Transmission device and transmission method

Abstract

To provide a transmission device capable of increasing data reception quality in a propagation environment including LOS.SOLUTION: A transmission device includes: a signal processing circuit for generating a first control signal, a second control signal, a first transmission signal sequence after phase change, and a second transmission signal sequence after phase change; and a transmitter for transmitting the first control signal, the first transmission signal sequence after phase change, the second control signal, and the second transmission signal sequence after phase change. The transmission device performs phase change of a plurality of data symbols of a first modulation signal sequence and a plurality of data symbols of a second modulation signal sequence according to a first phase change value which changes periodically, generates the first transmission signal sequence and the second transmission signal sequence from the first modulation signal sequence after phase change and the second modulation signal sequency after phase change, and performs phase change for the first transmission signal sequence and the second transmission sequence according to a second phase change value which is constant in time.SELECTED DRAWING: Figure 22

Description

[Technical Field]

[0001] The present disclosure particularly relates to a transmitting device and a receiving device that perform communication using multiple antennas. [Background technology]

[0002] In a line-of-sight (LOS) environment where direct waves are dominant, a communication method using multiple antennas is called MIMO (Multiple-Input Multiple-Output), and one such method is described in Non-Patent Document 1 as a transmission method for obtaining good reception quality. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] “MIMO for DVB-NGH, the next generation mobile TV broadcasting,” IEEE Commun. Mag., vol.57, no.7, pp.130-137, July 2013. [Non-patent document 2] “Standard conformable antenna diversity techniques for OFDM and its application to the DVB-T system,” IEEE Globecom 2001, pp.3100-3105, Nov. 2001. [Non-patent document 3] IEEE P802.11n(D3.00) Draft STANDARD for Information Technology-Telecommunications and information exchange between systems-Local and metropolitan area networks-Specific requirements-Part11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications, 2007. Summary of the Invention

[0004] Non-limiting examples of the present disclosure provide a transmitting device that improves the reception quality of data in a propagation environment that includes LOS.

[0005] A transmitting device according to an aspect of the present disclosure includes: a signal processing circuit that generates a first control signal and a second control signal by performing a cyclic shift diversity method, and a phase-altered first transmission signal sequence z1(i) and a phase-altered second transmission signal sequence z2(i) by performing first signal processing and second signal processing, where i is a symbol number; and a transmitter that transmits the first control signal and the phase-altered first transmission signal sequence z1(i) and the second control signal and the phase-altered second transmission signal sequence z2(i) via multiple antennas in a single carrier mode, wherein the first signal processing performs phase alteration on a plurality of data symbols of a first modulated signal sequence s1(i) and a plurality of data symbols of a second modulated signal sequence s2(i) in accordance with a first phase alteration value that changes periodically with a period N, where N is an integer greater than or equal to 2. the first phase modification value applied to the first modulated signal sequence s1(i) is equal in absolute value to the first phase modification value applied to the second modulated signal sequence s2(i) but differs in sign; in the second signal processing, the first transmit signal sequence z1(i) and the second transmit signal sequence z2(i) are generated from the phase-modulated first modulated signal sequence s1(i) and the phase-modulated second modulated signal sequence s2(i), and phase modifications are performed on the first transmit signal sequence z1(i) and the second transmit signal sequence z2(i) according to a time-constant second phase modification value provided for each of the first transmit signal sequence z1(i) and the second transmit signal sequence z2(i); and the second phase modification value applied to the first transmit signal sequence z1(i) is different from the second phase modification value applied to the second transmit signal sequence z2(i).

[0006] A transmission method according to one aspect of the present disclosure is a transmission method executed by a transmitting device, the transmission method including the steps of: generating a first control signal and a second control signal by performing a cyclic shift diversity method; and generating a phase-altered first transmission signal sequence z1(i) and a phase-altered second transmission signal sequence z2(i) by performing first signal processing and second signal processing, where i is a symbol number; and transmitting the first control signal and the phase-altered first transmission signal sequence z1(i) and the second control signal and the phase-altered second transmission signal sequence z2(i) via multiple antennas in a single carrier mode, wherein the first signal processing performs phase alteration on a plurality of data symbols of a first modulated signal sequence s1(i) and a plurality of data symbols of a second modulated signal sequence s2(i) in accordance with a first phase alteration value that changes periodically with a period N, where N is an integer equal to or greater than 1. the first phase modification value applied to the first modulated signal sequence s1(i) has the same absolute value but a different sign from the first phase modification value applied to the second modulated signal sequence s2(i); in the second signal processing, the first transmit signal sequence z1(i) and the second transmit signal sequence z2(i) are generated from the phase-modulated first modulated signal sequence s1(i) and the phase-modulated second modulated signal sequence s2(i), and phase modifications are performed on the first transmit signal sequence z1(i) and the second transmit signal sequence z2(i) in accordance with a time-constant second phase modification value provided for each of the first transmit signal sequence z1(i) and the second transmit signal sequence z2(i); and the second phase modification value applied to the first transmit signal sequence z1(i) is different from the second phase modification value applied to the second transmit signal sequence z2(i).

[0007] These general and specific aspects may be implemented in any combination of systems, devices, and methods.

[0008] As described above, according to the present disclosure, it is possible to improve the reception quality of data in a propagation environment including LOS, thereby making it possible to provide high-quality communication services.

[0009] Further advantages and benefits of certain aspects of the present disclosure will become apparent from the specification and drawings. Such advantages and / or benefits may be provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of them may be provided to obtain one or more identical features. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a diagram showing an example of the configuration of a transmission device according to the present embodiment. [Figure 2] FIG. 2 is a diagram showing an example of the configuration of a signal processing unit in FIG. 1; [Figure 3] FIG. 2 is a diagram showing an example of the configuration of the radio section of FIG. 1; [Figure 4] FIG. 2 is a diagram showing an example of a frame configuration of the transmission signal of FIG. 1. [Figure 5] FIG. 2 is a diagram showing an example of a frame configuration of the transmission signal of FIG. 1. [Figure 6] FIG. 3 is a diagram showing an example of the configuration of a portion relating to control information generation in FIG. 2; [Figure 7] FIG. 2 is a diagram showing an example of the configuration of the antenna unit in FIG. 1; [Figure 8] FIG. 2 is a diagram showing a configuration example of a receiving device according to the present embodiment. [Figure 9] FIG. 2 is a diagram showing the relationship between a transmitting device and a receiving device. [Figure 10] FIG. 9 is a diagram showing an example of the configuration of the antenna unit in FIG. 8. [Figure 11] FIG. 6 is a diagram showing a part of the frame in FIG. 5; [Figure 12] FIG. 2 is a diagram showing an example of a modulation method used in the mapping unit of FIG. 1; [Figure 13] FIG. 2 is a diagram showing an example of a frame configuration of the transmission signal of FIG. 1. [Figure 14] FIG. 2 is a diagram showing an example of a frame configuration of the transmission signal of FIG. 1. [Figure 15] FIG. 1 shows an example of a configuration using a CCD. [Figure 16] FIG. 1 is a diagram showing an example of carrier allocation when OFDM is used. [Figure 17]FIG. 1 is a diagram showing an example of the configuration of a transmission device based on the DVB-NGH standard. [Figure 18] FIG. 2 is a diagram showing an example of the configuration of a signal processing unit in FIG. 1; [Figure 19] FIG. 2 is a diagram showing an example of the configuration of a signal processing unit in FIG. 1; [Figure 20] FIG. 2 is a diagram showing an example of the configuration of a signal processing unit in FIG. 1; [Figure 21] FIG. 2 is a diagram showing an example of the configuration of a signal processing unit in FIG. 1; [Figure 22] FIG. 2 is a diagram showing an example of the configuration of a signal processing unit in FIG. 1; [Figure 23] FIG. 1 is a diagram showing an example of the configuration of a base station. [Figure 24] FIG. 2 is a diagram showing an example of the configuration of a terminal. [Figure 25] FIG. 2 is a diagram showing an example of a frame structure of a modulated signal. [Figure 26] FIG. 2 is a diagram showing an example of communication between a base station and a terminal. [Figure 27] FIG. 2 is a diagram showing an example of communication between a base station and a terminal. [Figure 28] FIG. 2 is a diagram showing an example of the configuration of a signal processing unit in FIG. 1; [Figure 29] FIG. 2 is a diagram showing an example of the configuration of a signal processing unit in FIG. 1; [Figure 30] FIG. 2 is a diagram showing an example of the configuration of a signal processing unit in FIG. 1; [Figure 31] FIG. 2 is a diagram showing an example of the configuration of a signal processing unit in FIG. 1; [Figure 32] FIG. 2 is a diagram showing an example of the configuration of a signal processing unit in FIG. 1; [Figure 33] FIG. 2 is a diagram showing an example of the configuration of a signal processing unit in FIG. 1; [Figure 34] FIG. 1 is a diagram showing an example of a system configuration in a state in which a base station and a terminal are communicating with each other. [Figure 35] FIG. 2 is a diagram showing an example of communication between a base station and a terminal. [Figure 36] FIG. 10 is a diagram showing an example of data included in a reception capability notification symbol. [Figure 37] FIG. 10 is a diagram showing an example of data included in a reception capability notification symbol. [Figure 38] FIG. 10 is a diagram showing an example of data included in a reception capability notification symbol. [Figure 39]FIG. 2 is a diagram showing an example of a frame configuration of a transmission signal. [Figure 40] FIG. 2 is a diagram showing an example of a frame configuration of a transmission signal. [Figure 41] FIG. 1 is a diagram showing an example of the configuration of a receiving device. [Figure 42] FIG. 1 is a diagram showing an example of a frame configuration using a multicarrier transmission method. [Figure 43] FIG. 1 is a diagram showing an example of a frame configuration using a single carrier transmission method. [Figure 44] FIG. 1 is a diagram showing an example of the configuration of a transmission device. [Figure 45] FIG. 10 is a diagram showing an example of a symbol arrangement method on the time axis. [Figure 46] FIG. 10 is a diagram showing an example of a symbol arrangement method on the frequency axis. [Figure 47] FIG. 10 is a diagram showing an example of a symbol arrangement method on the time and frequency axes. [Figure 48] FIG. 10 is a diagram showing an example of a symbol arrangement method on the time axis. [Figure 49] FIG. 10 is a diagram showing an example of a symbol arrangement method on the frequency axis. [Figure 50] FIG. 10 is a diagram showing an example of a symbol arrangement method on the time and frequency axes. [Figure 51] FIG. 2 is a diagram showing an example of the configuration of a modulated signal. [Figure 52] FIG. 2 is a diagram showing an example of a frame configuration when a modulated signal is transmitted; [Figure 53] FIG. 2 is a diagram showing an example of a frame configuration when a modulated signal is transmitted; [Figure 54] FIG. 2 is a diagram showing an example of the configuration of a signal processing unit in the transmitting device. [Figure 55] FIG. 2 is a diagram showing an example of the configuration of a radio unit in a transmitting device. [Figure 56] FIG. 2 is a diagram showing an example of the configuration of a signal processing unit in the transmitting device. [Figure 57] FIG. 2 is a diagram showing an example of the configuration of a modulated signal. [Figure 58] FIG. 2 is a diagram showing an example of a frame configuration when a modulated signal is transmitted; [Figure 59] FIG. 10 is a diagram showing an example in which phase change units are arranged before and after a weighting synthesis unit. [Figure 60] FIG. 10 is a diagram showing an example in which phase change units are arranged before and after a weighting synthesis unit. [Figure 61] FIG. 10 is a diagram showing an example in which phase change units are arranged before and after a weighting synthesis unit. [Figure 62] FIG. 10 is a diagram showing an example in which phase change units are arranged before and after a weighting synthesis unit. [Figure 63] FIG. 10 is a diagram showing an example in which phase change units are arranged before and after a weighting synthesis unit. [Figure 64] FIG. 10 is a diagram showing an example in which phase change units are arranged before and after a weighting synthesis unit. [Figure 65] FIG. 10 is a diagram showing an example in which phase change units are arranged before and after a weighting synthesis unit. [Figure 66] FIG. 10 is a diagram showing an example in which phase change units are arranged before and after a weighting synthesis unit. [Figure 67] FIG. 10 is a diagram showing an example in which phase change units are arranged before and after a weighting synthesis unit. [Figure 68] FIG. 4 is a diagram for explaining the operation of a mapping unit. [Figure 69] FIG. 10 is a diagram showing an example of a signal point arrangement in mapping. [Figure 70] FIG. 10 is a diagram showing an example of a signal point arrangement in mapping. [Figure 71] FIG. 10 is a diagram showing an example of a signal point arrangement in mapping. [Figure 72] FIG. 10 is a diagram showing an example of a signal point arrangement in mapping. [Figure 73] FIG. 1 is a diagram showing an example of the configuration of a transmission device. [Figure 74] FIG. 4 is a diagram showing the operation of a mapping unit. [Figure 75] FIG. 4 is a diagram showing the operation of a mapping unit. [Figure 76] FIG. 4 is a diagram showing the operation of a mapping unit. [Figure 77] FIG. 4 is a diagram showing the operation of a mapping unit. [Figure 78] FIG. 4 is a diagram showing the operation of a mapping unit. DETAILED DESCRIPTION OF THE INVENTION

[0011] (Communication methods in LOS environments) In an LOS environment where direct waves are dominant, a communication method using multiple antennas, such as a communication method called MIMO, is known as a transmission method for obtaining good reception quality, and there is a method described in Non-Patent Document 1.

[0012] FIG. 17 shows an example of the configuration of a transmitting device based on the DVB-NGH (Digital Video Broadcasting - Next Generation Handheld) standard, as described in Non-Patent Document 1, when there are two transmitting antennas and two modulated transmission signals (transmission streams). In the transmitting device, data 003 coded by a coding unit 002 is divided into data 005A and data 005B by a dividing unit 004. Data 005A is interleaved by an interleaver 004A and mapped by a mapping unit 006A. Similarly, data 005B is interleaved by an interleaver 004B and mapped by a mapping unit 006B. Weighting and combining units 008A and 008B receive mapped signals 007A and 007B, respectively, and perform weighting and combining to generate weighted and combined signals 009A and 016B. The weighted and combined signal 016B is then phase-shifted. Then, the radio units 010A and 010B perform processes such as processing related to OFDM (orthogonal frequency division multiplexing), frequency conversion, and amplification, and transmit a transmission signal 011A from the antenna 012A and a transmission signal 011B from the antenna 012B.

[0013] Conventional configurations do not take into consideration the combined transmission of single-stream signals, and in such cases, it is considered advisable to introduce a new transmission method to improve the reception quality of data, particularly in single-stream receiving devices.

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0015] (Embodiment 1) The transmission method, transmission device, reception method, and reception device of this embodiment will be described in detail.

[0016] 1 shows an example of the configuration of a transmitting device such as a base station, an access point, or a broadcasting station in this embodiment. Error correction coding unit 102 receives data 101 and control signal 100 as input, performs error correction coding based on information about the error correction code included in control signal 100 (e.g., information about the error correction code, code length (block length), and coding rate), and outputs coded data 103. Note that error correction coding unit 102 may include an interleaver, and if it does include an interleaver, it may rearrange the data after coding and output coded data 103.

[0017] Mapping section 104 receives encoded data 103 and control signal 100 as input, performs mapping corresponding to the modulation scheme based on information about the modulated signal included in control signal 100, and outputs baseband signal 105_1, which is a mapped signal, and baseband signal 105_2, which is a mapped signal. Note that mapping section 104 uses a first sequence to generate mapped signal 105_1, and a second sequence to generate mapped signal 105_2. At this time, the first sequence and the second sequence are different.

[0018] Signal processing unit 106 receives mapped signals 105_1 and 105_2, signal group 110, and control signal 100 as input, performs signal processing based on control signal 100, and outputs processed signals 106_A and 106_B. Here, processed signal 106_A is represented as u1(i), and processed signal 106_B is represented as u2(i). i is a symbol number, and is an integer equal to or greater than 0, for example. Signal processing will be described later with reference to FIG. 2.

[0019] Radio unit 107_A receives processed signal 106_A and control signal 100, processes processed signal 106_A based on control signal 100, and outputs transmission signal 108_A. Transmission signal 108_A is then output as a radio wave from antenna unit #A 109_A.

[0020] Similarly, radio unit 107_B receives processed signal 106_B and control signal 100, processes processed signal 106_B based on control signal 100, and outputs transmission signal 108_B. Transmission signal 108_B is then output as a radio wave from antenna unit #B 109_B.

[0021] Antenna unit #A 109_A receives control signal 100. Based on control signal 100, it processes transmission signal 108_A and outputs it as radio waves. However, antenna unit #A 109_A does not necessarily receive control signal 100 as input.

[0022] Similarly, antenna unit #B 109_B receives control signal 100. In this case, it processes transmission signal 108_B based on control signal 100 and outputs a radio wave. However, antenna unit #B 109_B does not necessarily receive control signal 100 as input.

[0023] The control signal 100 may be generated based on information transmitted by the device in FIG. 1 that is the communication partner, or the device in FIG. 1 may have an input unit and the control signal 100 may be generated based on information input from the input unit.

[0024] 2 shows an example of the configuration of signal processing unit 106 in FIG. 1. Weighting combination unit (precoding unit) 203 receives mapped signal 201A (mapped signal 105_1 in FIG. 1), mapped signal 201B (mapped signal 105_2 in FIG. 1), and control signal 200 (control signal 100 in FIG. 1), performs weighting combination (precoding) based on control signal 200, and outputs weighted signal 204A and weighted signal 204B. In this case, mapped signal 201A is represented as s1(t), mapped signal 201B as s2(t), weighted signal 204A as z1(t), and weighted signal 204B as z2'(t). Note that t represents time, for example. s1(t), s2(t), z1(t), and z2'(t) are defined as complex numbers. Therefore, they may be real numbers.

[0025] The weighting synthesis unit (precoding unit) 203 performs the following calculation.

[0026]

number

[0027] In equation (1), a, b, c, and d are defined as complex numbers. Note that a, b, c, and d may also be real numbers. Note that i is the symbol number.

[0028] Phase shifter 205B receives weighted and combined signal 204B and control signal 200 as input, and performs a phase shift on weighted and combined signal 204B based on control signal 200, outputting phase-shifted signal 206B. Phase-shifted signal 206B is represented by z2(t), which is defined as a complex number. z2(t) may also be a real number.

[0029] The specific operation of the phase changer 205B will be described. For example, the phase changer 205B applies a phase change of y(i) to z2'(i). Therefore, it can be expressed as z2(i) = y(i) × z2'(i), where i is the symbol number and is an integer equal to or greater than 0.

[0030] For example, the phase change value is set as follows: N is an integer equal to or greater than 2, and N is the phase change period. Setting N to an odd number equal to or greater than 3 may improve the data reception quality.

[0031]

number

[0032] j is the imaginary unit. However, the formula (2) is merely an example and is not limited to this. Therefore, the phase change value y(i)=e j×δ(i) It is expressed as:

[0033] In this case, z1(i) and z2(i) can be expressed by the following equations:

[0034]

number

[0035] Note that δ(i) is a real number. Furthermore, z1(i) and z2(i) are transmitted from a transmitting device at the same time and at the same frequency (same frequency band).

[0036] In equation (3), the phase change value is not limited to equation (2), and for example, a method of periodically and regularly changing the phase is conceivable.

[0037] The matrices (precoding matrices) in equations (1) and (3) are

[0038]

number

[0039] For example, the matrix F may be one of the following matrices:

[0040]

number

[0041]

number

[0042]

number

[0043]

number

[0044]

number

[0045]

number

[0046]

number

[0047]

number

[0048] In addition, in formulas (5), (6), (7), (8), (9), (10), (11), and (12), α may be a real number or an imaginary number, and β may be a real number or an imaginary number. However, α is not 0 (zero). And β is also not 0 (zero).

[0049]

number

[0050]

number

[0051]

number

[0052]

number

[0053]

number

[0054]

number

[0055]

number

[0056]

number

[0057] In equations (13), (15), (17), and (19), β may be a real number or an imaginary number. However, β is not 0 (zero). (θ is a real number.)

[0058]

number

[0059]

number

[0060]

number

[0061]

number

[0062]

number

[0063]

number

[0064]

number

[0065]

number

[0066]

number

[0067]

number

[0068]

number

[0069]

number

[0070] However, θ 11 (i), θ 21 (i), λ(i) are functions of symbol number i and are real numbers. λ is, for example, a fixed value, a real number, and does not have to be a fixed value. α may be a real number or an imaginary number. β may be a real number or an imaginary number. However, α is not 0 (zero). And β is also not 0 (zero). Also, θ 11 , θ 21 is a real number.

[0071] Furthermore, in addition to these, it is also possible to implement each embodiment of the present disclosure by using any of the precoding matrices shown below.

[0072]

number

[0073]

number

[0074]

number

[0075]

number

[0076] In addition, β in equations (34) and (36) may be a real number or an imaginary number, but β is not 0 (zero).

[0077] Insertion section 207A receives weighted combined signal 204A, pilot symbol signal pa(t) 251A at time t, preamble signal 252, control information symbol signal 253, and control signal 200 as input, and outputs baseband signal 208A based on the frame configuration, based on the frame configuration information included in control signal 200.

[0078] Similarly, insertion unit 207B receives as input phase-changed signal 206B, pilot symbol signal pb(t) 251B at time t, preamble signal 252, control information symbol signal 253, and control signal 200, and outputs baseband signal 208B based on the frame configuration, based on the frame configuration information included in control signal 200.

[0079] Phase changer 209B receives baseband signal 208B and control signal 200, changes the phase of baseband signal 208B based on control signal 200, and outputs phase-changed signal 210B. Baseband signal 208B is a function of symbol number i, expressed as x'(i). Then, phase-changed signal x(i) 210B is expressed as x(i)=e j×ε(i) It can be expressed as ×x'(i), where i is an integer greater than or equal to 0, and j is the imaginary unit.

[0080] As will be explained later, the operation of phase changer 209B may be CDD (Cyclic Delay Diversity) or CSD (Cyclic Shift Diversity) as described in Non-Patent Document 2 and Non-Patent Document 3. Hereinafter, these will be referred to as CDD / CSD. Phase changer 209B then performs phase change on symbols present in the frequency axis direction. That is, phase changer 209B performs phase change on data symbols, pilot symbols, control information symbols, etc.

[0081] Fig. 3 shows an example of the configuration of radio units 107_A and 107_B in Fig. 1. Serial-to-parallel conversion unit 302 receives signal 301 and control signal 300 (control signal 100 in Fig. 1) as input, performs serial-to-parallel conversion based on control signal 300, and outputs signal 303 after serial-to-parallel conversion.

[0082] The inverse Fourier transform unit 304 receives the serial-to-parallel converted signal 303 and the control signal 300 as input, and performs an inverse Fourier transform, for example, an inverse fast Fourier transform (IFFT), based on the control signal 300, and outputs a post-inverse Fourier transform signal 305.

[0083] Processing unit 306 receives signal 305 after inverse Fourier transform and control signal 300 as input, performs processing such as frequency conversion and amplification based on control signal 300 , and outputs modulated signal 307 .

[0084] For example, if signal 301 is signal 106_A after signal processing in Fig. 1, modulated signal 307 corresponds to transmission signal 108_A in Fig. 1. Also, if signal 301 is signal 106_B after signal processing in Fig. 1, modulated signal 307 corresponds to transmission signal 108_B in Fig. 1.

[0085] FIG. 4 shows the frame structure of the transmission signal 108_A in FIG. 1. In FIG. 4, the horizontal axis represents frequency (carrier) and the vertical axis represents time. Since a multi-carrier transmission method such as OFDM is used, symbols exist in the carrier direction. FIG. 4 shows symbols for all carriers. Also, FIG. 4 shows symbols from time $1 to time $11.

[0086] Fig. 4 shows pilot symbols 401 (pilot signal 251A in Fig. 2), data symbols 402, and other symbols 403. In this case, the pilot symbols are, for example, PSK (Phase Shift Keying) symbols, and are symbols used by a receiving device receiving this frame to perform channel estimation (estimation of propagation path fluctuations), frequency offset, and phase fluctuation estimation, and it is preferable that, for example, the transmitting device in Fig. 1 and the receiving device receiving the frame in Fig. 4 share the same method of transmitting pilot symbols.

[0087] Incidentally, the mapped signal 201A (mapped signal 105_1 in FIG. 1) is named "stream #1," and the mapped signal 201B (mapped signal 105_2 in FIG. 1) is named "stream #2." This also applies to the following description.

[0088] The data symbol 402 is a symbol corresponding to the baseband signal 208A generated by the signal processing according to FIG. 2, and therefore the data symbol 402 is either a "symbol including both a symbol of "Stream #1" and a symbol of "Stream #2", or a "symbol of "Stream #1", or a "symbol of "Stream #2", which is determined by the configuration of the precoding matrix used in the weighting and combining unit 203.

[0089] The other symbols 403 are symbols corresponding to the preamble signal 242 and the control information symbol signal 253 in Fig. 2. However, the other symbols may include symbols other than the preamble and the control information symbols. In this case, the preamble may transmit data (for control) and may be composed of symbols for signal detection, symbols for frequency synchronization and time synchronization, symbols for channel estimation (symbols for estimating propagation path fluctuations), etc. The control information symbols are symbols containing control information that enable a receiving device that receives the frame in Fig. 4 to demodulate and decode the data symbols.

[0090] For example, all carriers from time $1 to time $4 in FIG. 4 are other symbols 403. At time $5, Carrier 1 to carrier 11 are data symbols 402. Carrier 12 will have pilot symbol 401, Carrier 13 to carrier 23 are data symbols 402, Carrier 24 has pilot symbol 401, and the rest of the description is omitted. At time $6, Carrier 1 and Carrier 2 become data symbols 402, Carrier 3 has pilot symbol 401, and the rest of the description is omitted. - The description from time $7 to time $10 is omitted. At time $11, Carrier 1 to Carrier 29 are omitted. Carrier 30 at time $11 becomes pilot symbol 401, At time $11, carriers 31 to 36 are data symbols 402.

[0091] Fig. 5 shows the frame structure of transmission signal 108_B in Fig. 1. In Fig. 5, the horizontal axis represents frequency (carrier) and the vertical axis represents time. Since a multi-carrier transmission method such as OFDM is used, symbols exist in the carrier direction. Fig. 5 shows symbols for all carriers. Fig. 5 also shows symbols from time $1 to time $11.

[0092] 5 shows pilot symbols 501 (pilot signal 251B in FIG. 2), data symbols 502, and other symbols 503. In this case, the pilot symbols are, for example, PSK symbols, and are symbols used by a receiving device receiving this frame to perform channel estimation (estimation of propagation path fluctuations), frequency offset, and phase fluctuation estimation, and it is preferable that, for example, the transmitting device in FIG. 1 and the receiving device receiving the frame in FIG. 5 share the same method of transmitting pilot symbols.

[0093] Data symbol 502 is a symbol corresponding to baseband signal 208B generated by signal processing according to FIG. 2, and therefore data symbol 502 is either a "symbol including both a symbol of "Stream #1" and a symbol of "Stream #2", or a "symbol of "Stream #1", or a "symbol of "Stream #2", which is determined by the configuration of the precoding matrix used in weighting and combining unit 203.

[0094] Other symbols 503 are symbols corresponding to the preamble signal 252 and control information symbol signal 253 in Fig. 2. However, the other symbols may include symbols other than the preamble and control information symbols. In this case, the preamble may transmit data (for example, control data) and may be composed of symbols for signal detection, symbols for frequency synchronization and time synchronization, symbols for channel estimation, etc. The control information symbols are symbols including control information that enables a receiving device that receives the frame in Fig. 5 to demodulate and decode the data symbols.

[0095] For example, in Figure 5 From time $1 to time $4, All carriers are other symbols 403. At time $5, Carrier 1 to carrier 11 are data symbols 402, Carrier 12 will have pilot symbol 401, Carrier 13 to carrier 23 are data symbols 402, Carrier 24 becomes pilot symbol 401, and thereafter, description of the carrier at time $5 is omitted. At time $6, Carrier 1 and Carrier 2 become data symbols 402, Carrier 3 becomes pilot symbol 401, and thereafter, description of the carrier at time $6 is omitted. The entries from time $7 to time $10 are omitted. At time $11, The descriptions of carriers 1 to 29 are omitted. Carrier 30 will become pilot symbol 401, Carrier 31 to carrier 36 are data symbols 402 .

[0096] When a symbol exists on carrier A, time $B in Figure 4 and a symbol exists on carrier A, time $B in Figure 5, the symbol on carrier A, time $B in Figure 4 and the symbol on carrier A, time $B in Figure 5 are transmitted at the same time and on the same frequency. Note that the frame structure is not limited to Figures 4 and 5, and Figures 4 and 5 are merely examples of frame structures.

[0097] The other symbols in Figures 4 and 5 are symbols corresponding to "preamble signal 252 and control information symbol signal 253 in Figure 2", and therefore, when other symbols 503 in Figure 5 at the same time and on the same frequency (same carrier) as other symbols 403 in Figure 4 transmit control information, they transmit the same data (same control information).

[0098] It is assumed that the receiving device receives the frame in Figure 4 and the frame in Figure 5 simultaneously, but the receiving device can obtain the data transmitted by the transmitting device even if it receives the frame in Figure 4 or the frame in Figure 5.

[0099] FIG. 6 shows an example of the configuration of a portion related to control information generation for generating control information symbol signal 253 in FIG.

[0100] Control information mapping section 602 receives control information data 601 and control signal 600 as input, performs mapping on control information data 601 using a modulation method based on control signal 600, and outputs control information mapped signal 603. Note that control information mapped signal 603 corresponds to control information symbol signal 253 in FIG. 2 .

[0101] Fig. 7 shows an example of the configuration of antenna unit #A 109_A and antenna unit #B 109_B in Fig. 1. In this example, antenna unit #A 109_A and antenna unit #B 109_B are configured with a plurality of antennas.

[0102] The distributor 702 receives the transmission signal 701, distributes it, and outputs transmission signals 703_1, 703_2, 703_3, and 703_4.

[0103] The multiplication unit 704_1 receives the transmission signal 703_1 and the control signal 700 as input, multiplies the transmission signal 703_1 by a multiplication coefficient based on the information of the multiplication coefficient included in the control signal 700, and outputs the multiplied signal 705_1, which is output as a radio wave from the antenna 706_1.

[0104] If the transmitted signal 703_1 is Tx1(t) and the multiplication coefficient is W1, the signal 705_1 after multiplication is expressed as Tx1(t)×W1, where t indicates time and W1 can be defined as a complex number, and therefore may be a real number.

[0105] The multiplication unit 704_2 receives the transmission signal 703_2 and the control signal 700 as input, multiplies the transmission signal 703_2 by a multiplication coefficient based on the information of the multiplication coefficient included in the control signal 700, and outputs the multiplied signal 705_2, which is output as a radio wave from the antenna 706_2.

[0106] If the transmission signal 703_2 is Tx2(t) and the multiplication coefficient is W2, the signal 705_2 after multiplication is expressed as Tx2(t)×W2, where t indicates time and W2 can be defined as a complex number, and therefore may be a real number.

[0107] The multiplication unit 704_3 receives the transmission signal 703_3 and the control signal 700 as input, multiplies the transmission signal 703_3 by a multiplication coefficient based on the information of the multiplication coefficient included in the control signal 700, and outputs the multiplied signal 705_3, which is output as a radio wave from the antenna 706_3.

[0108] If the transmit signal 703_3 is Tx3(t) and the multiplication coefficient is W3, the signal 705_3 after multiplication is expressed as Tx3(t)×W3. W3 can be defined as a complex number, and therefore may be a real number.

[0109] The multiplication unit 704_4 receives the transmission signal 703_4 and the control signal 700 as input, and multiplies the transmission signal 703_4 by the multiplication coefficient based on the information on the multiplication coefficient included in the control signal 700, and outputs the multiplied signal 705_4, which is output as a radio wave from the antenna 706_4.

[0110] If the transmit signal 703_4 is Tx4(t) and the multiplication coefficient is W4, the signal 705_4 after multiplication is expressed as Tx4(t)×W4. W4 can be defined as a complex number, and therefore may be a real number.

[0111] It should be noted that "the absolute value of W1, the absolute value of W2, the absolute value of W3, and the absolute value of W4 may be equal." In this case, it is equivalent to a phase change. Naturally, the absolute values ​​of W1, W2, W3, and W4 do not have to be equal.

[0112] 7, the antenna unit is described as being configured with four antennas, but the number of antennas is not limited to four, and may be configured with two or more antennas. The antenna unit may also be configured with four antennas and four multiplication units.

[0113] When antenna unit #A 109_A in Fig. 1 has the configuration shown in Fig. 7, transmission signal 701 corresponds to transmission signal 108_A in Fig. 1. When antenna unit #B 109_B in Fig. 1 has the configuration shown in Fig. 7, transmission signal 701 corresponds to transmission signal 108_B in Fig. 1, and corresponds to transmission signal 108_B in Fig. 1. However, antenna unit #A 109_A and antenna unit #B 109_B do not have to be configured as shown in Fig. 7, and as described above, the antenna unit does not need to receive control signal 100 as an input.

[0114] FIG. 8 shows an example of the configuration of a receiving device that receives a modulated signal when the transmitting device of FIG. 1 transmits a transmission signal having the frame configuration of, for example, FIG. 4 or FIG.

[0115] Radio section 803X receives signal 802X received by antenna section #X 801X as input, performs processing such as frequency conversion and Fourier transform, and outputs baseband signal 804X.

[0116] Similarly, radio section 803Y receives signal 802Y received by antenna section #Y 801Y as input, performs processing such as frequency conversion and Fourier transform, and outputs baseband signal 804Y.

[0117] 8 shows antenna unit #X 801X and antenna unit #Y 801Y configured to receive control signal 810 as input, they may also be configured not to receive control signal 810. Operation when control signal 810 is present as an input will be described in detail later.

[0118] Incidentally, the relationship between a transmitting device and a receiving device is shown in Fig. 9. Antennas 901_1 and 901_2 in Fig. 9 are transmitting antennas, and the antenna 901_1 in Fig. 9 corresponds to the antenna unit #A 109_A in Fig. 1. The antenna 901_2 in Fig. 9 corresponds to the antenna unit #B 109_B in Fig. 1.

[0119] 9 are receiving antennas, and the antenna 902_1 in Fig. 9 corresponds to the antenna unit #X 801X in Fig. 8. The antenna 902_2 in Fig. 9 corresponds to the antenna unit #Y 801Y in Fig. 8.

[0120] 9, a signal transmitted from transmitting antenna 901_1 is denoted by u1(i), a signal transmitted from transmitting antenna 901_2 is denoted by u2(i), a signal received by receiving antenna 902_1 is denoted by r1(i), and a signal received by receiving antenna 902_2 is denoted by r2(i). Note that i indicates a symbol number and is, for example, an integer equal to or greater than 0.

[0121] The propagation coefficient from the transmitting antenna 901_1 to the receiving antenna 902_1 is h11(i), the propagation coefficient from the transmitting antenna 901_1 to the receiving antenna 902_2 is h21(i), the propagation coefficient from the transmitting antenna 901_2 to the receiving antenna 902_1 is h12(i), and the propagation coefficient from the transmitting antenna 901_2 to the receiving antenna 902_2 is h22(i). Then, the following relational expressions are established.

[0122]

number

[0123] Note that n1(i) and n2(i) are noise.

[0124] The channel estimation unit 805_1 for modulated signal u1 in FIG. 8 receives baseband signal 804X as input, and estimates the channel of modulated signal u1, that is, estimates h11(i) in equation (37), using the preamble and / or pilot symbols in FIGS. 4 and 5, and outputs channel estimation signal 806_1.

[0125] The channel estimation unit 805_2 for modulated signal u2 receives baseband signal 804X as input, and estimates the channel of modulated signal u2, that is, estimates h12(i) in equation (37), using the preamble and / or pilot symbols in Figures 4 and 5, and outputs channel estimation signal 806_2.

[0126] The channel estimation unit 807_1 for modulated signal u1 receives baseband signal 804Y as input, and estimates the channel of modulated signal u1, that is, estimates h21(i) in equation (37), using the preamble and / or pilot symbols in Figures 4 and 5, and outputs channel estimation signal 808_1.

[0127] The channel estimation unit 807_2 for modulated signal u2 receives baseband signal 804Y as input, and estimates the channel of modulated signal u2, that is, estimates h22(i) in equation (37) using the preamble and / or pilot symbols in Figures 4 and 5, and outputs channel estimation signal 808_2.

[0128] Control information decoding section 809 receives baseband signals 804X and 804Y as input, demodulates and decodes the control information included in the "other symbols" in FIGS. 4 and 5, and outputs control signal 810 including the control information.

[0129] The signal processing unit 811 receives the channel estimation signals 806_1, 806_2, 808_1, 808_2, the baseband signals 804X, 804Y, and the control signal 810 as input, and performs demodulation and decoding using the relationship in equation (37) and based on the control information in the control signal 810 (e.g., information on the modulation method and the method related to the error correction code), and outputs received data 812.

[0130] Note that control signal 810 does not have to be generated by the method shown in Fig. 8. For example, control signal 810 in Fig. 8 may be generated based on information transmitted by a device that is the communication partner (Fig. 1) in Fig. 8, or the device in Fig. 8 may be equipped with an input unit and may be generated based on information input from the input unit.

[0131] Fig. 10 shows an example of the configuration of antenna unit #X 801X and antenna unit #Y 801Y in Fig. 8. In this example, antenna unit #X 801X and antenna unit #Y 801Y are configured with multiple antennas.

[0132] Multiplication section 1003_1 receives as input a received signal 1002_1 received by antenna 1001_1 and a control signal 1000, multiplies the received signal 1002_1 by a multiplication coefficient based on information on the multiplication coefficient included in the control signal 1000, and outputs a multiplied signal 1004_1.

[0133] If the received signal 1002_1 is Rx1(t) and the multiplication coefficient is D1, the signal 1004_1 after multiplication is expressed as Rx1(t)×D1, where t indicates time and D1 can be defined as a complex number, and therefore may be a real number.

[0134] Multiplication section 1003_2 receives as input a received signal 1002_2 received by antenna 1001_2 and a control signal 1000, multiplies the received signal 1002_2 by a multiplication coefficient based on information on the multiplication coefficient included in the control signal 1000, and outputs a multiplied signal 1004_2.

[0135] If the received signal 1002_2 is Rx2(t) and the multiplication coefficient is D2, the signal 1004_2 after multiplication is expressed as Rx2(t)×D2. D2 can be defined as a complex number, and therefore may be a real number.

[0136] Multiplication section 1003_3 receives as input a received signal 1002_3 received by antenna 1001_3 and a control signal 1000, multiplies the received signal 1002_3 by a multiplication coefficient based on information on the multiplication coefficient included in the control signal 1000, and outputs a multiplied signal 1004_3.

[0137] If the received signal 1002_3 is Rx3(t) and the multiplication coefficient is D3, the signal 1004_3 after multiplication is expressed as Rx3(t)×D3. D3 can be defined as a complex number, and therefore may be a real number.

[0138] Multiplication section 1003_4 receives as input a received signal 1002_4 received by antenna 1001_4 and a control signal 1000, multiplies the received signal 1002_4 by a multiplication coefficient based on information on the multiplication coefficient included in the control signal 1000, and outputs a multiplied signal 1004_4.

[0139] If the received signal 1002_4 is Rx4(t) and the multiplication coefficient is D4, the signal 1004_4 after multiplication is expressed as Rx4(t)×D4. D4 can be defined as a complex number, and therefore may be a real number.

[0140] The combining unit 1005 receives the multiplied signals 1004_1, 1004_2, 1004_3, and 1004_4 as input, combines the multiplied signals 1004_1, 1004_2, 1004_3, and 1004_4, and outputs a combined signal 1006. The combined signal 1006 is expressed as Rx1(t)×D1+Rx2(t)×D2+Rx3(t)×D3+Rx4(t)×D4.

[0141] 10, an example in which the antenna unit is configured with four antennas is described, but the number of antennas is not limited to four and may be two or more antennas. The antenna unit may also be configured with four antennas and four multiplication units.

[0142] When antenna unit #X 801X in Fig. 8 has the configuration shown in Fig. 10, received signal 802X corresponds to combined signal 1006 in Fig. 10, and control signal 710 corresponds to control signal 1000 in Fig. 10. When antenna unit #Y 801Y in Fig. 8 has the configuration shown in Fig. 10, received signal 802Y corresponds to combined signal 1006 in Fig. 10, and control signal 710 corresponds to control signal 1000 in Fig. 10. However, antenna unit #X 801X and antenna unit #Y 801Y do not have to have the configuration shown in Fig. 10, and the antenna units described above do not have to receive control signal 710 as an input.

[0143] In addition, the control signal 800 may be generated based on information sent by the device with which the communication is made, or the device may have an input unit and the control signal 800 may be generated based on information input from that input unit.

[0144] Next, as shown in Fig. 1, signal processing unit 106 of the transmitting device is inserted with phase shifting unit 205B and phase shifting unit 209B as shown in Fig. 2. The features and effects of this will be described.

[0145] As explained using Figures 4 and 5, phase change section 205B performs precoding (weighting and combining) on ​​mapped signal s1(i) 201A obtained by mapping using a first sequence and mapped signal s2(i) 201B obtained by mapping using a second sequence, and performs a phase change on one of the resulting weighted and combined signals 204A, 204B, where i is a symbol number and is an integer equal to or greater than 0.

[0146] Then, the weighted and combined signal 204A and the phase-changed signal 206B are transmitted at the same frequency and at the same time. Therefore, in Figures 4 and 5, a phase change is applied to the data symbol 502 in Figure 5.

[0147] In the case of Fig. 2, phase change section 205B performs the phase change on weighted and combined signal 204B, and therefore performs the phase change on data symbol 502 in Fig. 5. When performing the phase change on weighted and combined signal 204A, the phase change is performed on data symbol 402 in Fig. 4. This point will be explained later.

[0148] For example, Fig. 11 shows carrier 1 to carrier 5 and time $4 to time $6 extracted from the frame in Fig. 5. Note that Fig. 11 shows pilot symbols 501, data symbols 502, and other symbols 503, just like Fig. 5.

[0149] As described above, in the symbols shown in FIG. 11, phase change unit 205B applies phase change to the data symbols at (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6).

[0150] Therefore, the phase change value for the data symbol shown in FIG. 11 is (Carrier 1, Time $5) j×δ15(i) "year, (Carrier 2, Time $5) j×δ25(i) "year, (Carrier 3, Time $5) j×δ35(i) "year, (Carrier 4, Time $5) j×δ45(i) "year, (Carrier 5, Time $5) j×δ55(i) "year, (Carrier 1, Time $6) j×δ16(i) "year, (Carrier 2, time $6) j×δ26(i) "year, (Carrier 4, Time $6) j×δ46(i) "year, (Carrier 5, Time $6) j×δ56(i) "

[0151] On the other hand, in the symbol shown in Figure 11, Other symbols in (carrier 1, time $4), (carrier 2, time $4), (carrier 3, time $4), (carrier 4, time $4), and (carrier 5, time $4), and the pilot symbol in (carrier 3, time $6) are not subject to phase modification by phase modification unit 205B.

[0152] This is a characteristic feature of phase changer 205B. Note that, as shown in Fig. 4, data carriers are allocated at the "same carrier, same time" as the data symbols in (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6), which are the targets of phase change in Fig. 11.

[0153] That is, in Figure 4, (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6) are data symbols.

[0154] That is, data symbols undergoing MIMO transmission are the targets of phase modification by phase modification section 205 B. Performing MIMO transmission means transmitting a plurality of streams.

[0155] An example of the phase change that the phase change unit 205B applies to the data symbols is a method of performing a regular phase change on the data symbols, for example, a phase change with a period of N, as shown in equation (2). However, the method of changing the phase of the data symbols is not limited to this.

[0156] By doing so, it is possible to obtain the effect of improving the reception quality of data in a receiving device for data symbols undergoing MIMO transmission in an environment where direct waves are dominant, for example, an LOS environment. This effect will now be explained.

[0157] For example, the modulation method used in the mapping unit 104 in FIG. 1 is QPSK (Quadrature Phase Shift Keying). The mapped signal 201A in FIG. 2 is a QPSK signal, and the mapped signal 201B is also a QPSK signal. In other words, two QPSK streams are transmitted. Then, the signal processing unit 811 in FIG. 8 obtains 16 candidate signal points using, for example, channel estimation signals 806_1 and 806_2. QPSK can transmit 2 bits, and a total of 4 bits are transmitted using the two streams. Therefore, 2 4 = 16 candidate signal points. Note that another 16 candidate signal points can also be obtained using channel estimation signals 808_1 and 808_2, but the explanation is similar, so the explanation will focus on the 16 candidate signal points obtained using channel estimation signals 806_1 and 806_2.

[0158] An example of this state is shown in Figures 12A and 12B. In both Figures 12A and 12B, the horizontal axis is in-phase I and the vertical axis is quadrature Q, and there are 16 candidate signal points on the in-phase I-quadrature Q plane. One of the 16 candidate signal points is the signal point transmitted by the transmitting device. For this reason, they are called "16 candidate signal points."

[0159] In an environment where direct waves are dominant, for example, an LOS environment, the first case is considered as "a case where phase change unit 205B of FIG. 2 does not exist, that is, a case where phase change is not performed by phase change unit 205B of FIG. 2."

[0160] In the "first case," no phase change is performed, which may result in the state shown in Fig. 12A. When the state shown in Fig. 12A occurs, there are areas where signal points are dense, that is, where the distance between signal points is short, such as "signal points 1201 and 1202," "signal points 1203, 1204, 1205 and 1206," and "signal points 1207 and 1208," which may result in a decrease in data reception quality in the receiving device shown in Fig. 8.

[0161] To overcome this phenomenon, phase shifter 205B is inserted in Fig. 2. When phase shifter 205B is inserted, symbol number i will have a mixture of symbol numbers where signal points are densely packed, as in Fig. 12A, and symbol numbers where the distance between signal points is long, as in Fig. 12B. To address this situation, error correction coding is introduced, making it possible to obtain high error correction capabilities, and high data reception quality can be achieved in the receiving device of Fig. 8.

[0162] 2, phase modification section 205B in Fig. 2 does not modify the phase of "pilot symbols and preambles" used for channel estimation to demodulate (detect) data symbols, such as pilot symbols and preambles. This makes it possible to achieve, for data symbols, "a mixture of symbol numbers where there are dense signal points as in Fig. 12A and symbol numbers where the distance between signal points is long, depending on the symbol number i."

[0163] However, even if phase change is performed in phase change unit 205B of FIG. 2 on "pilot symbols and preambles" for channel estimation to demodulate (detect) data symbols, such as pilot symbols and preambles, there are cases where "in data symbols, it is possible to achieve a mixture of symbol numbers where "areas where signal points are densely packed" as in FIG. 12A and symbol numbers where "the distance between signal points is long" as in FIG. 12B, depending on symbol number i."

[0164] In this case, some condition is added to the phase change of the pilot symbols and preambles. For example, a method can be considered in which a different rule is set from the rule for phase change of the data symbols, and "phase change is applied to the pilot symbols and / or preambles." As an example, there is a method in which phase change is applied to the data symbols regularly with a period of N, and phase change is applied to the pilot symbols and / or preambles regularly with a period of M. N and M are integers equal to or greater than 2.

[0165] As described above, phase changer 209B receives baseband signal 208B and control signal 200 as input, changes the phase of baseband signal 208B based on control signal 200, and outputs phase-changed signal 210B. Baseband signal 208B is a function of symbol number i, expressed as x'(i). Then, phase-changed signal 210B(x(i)) is expressed as x(i)=e j×ε(i) It can be expressed as ×x'(i), where i is an integer greater than or equal to 0 and j is the imaginary unit.

[0166] The operation of the phase change unit 209B may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. The phase change unit 209B is characterized in that it performs phase change on symbols present in the frequency axis direction (it applies phase change to data symbols, pilot symbols, control information symbols, etc.).

[0167] Therefore, in this case, the symbol targeted by symbol number i is a data symbol, a pilot symbol, a control information symbol, a preamble (or other symbol), and so on.

[0168] In the case of Fig. 2, phase change section 209B applies a phase change to baseband signal 208B, and therefore applies a phase change to each symbol shown in Fig. 5. When applying a phase change to baseband signal 208A in Fig. 2, a phase change is applied to each symbol shown in Fig. 4. This point will be explained later.

[0169] Therefore, in the frame of FIG. 5, phase change section 209B of FIG. 2 applies phase change to all symbols (other symbols 503) of all carriers at time $1.

[0170] Similarly, the phase change unit 209B in FIG. 2 performs phase change on the following symbols: "All symbols of all carriers at time $2 (other symbols 503)" "All symbols of all carriers at time $3 (other symbols 503)" "All symbols of all carriers at time $4 (other symbols 503)" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $5" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $6" "All symbols of all carriers at time $7 (pilot symbol 501 or data symbol 502)" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $8" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $9" "All symbols of all carriers at time $10 (pilot symbol 501 or data symbol 502)" "All symbols of all carriers at time $11 (pilot symbol 501 or data symbol 502)" The following time and carrier information will be omitted.

[0171] FIG. 13 shows a frame configuration of transmission signal 108_A of FIG. 1 that is different from that of FIG. 4. In FIG. 13, components that operate in the same way as in FIG. 4 are given the same numbers. In FIG. 13, the horizontal axis is frequency (carrier) and the vertical axis is time. As in FIG. 4, a multi-carrier transmission method such as OFDM is used, so symbols exist in the carrier direction. As in FIG. 4, FIG. 13 shows symbols of all carriers. As in FIG. 4, FIG. 13 shows symbols from time $1 to time $11.

[0172] In FIG. 13, in addition to pilot symbols 401 (pilot signals 251A in FIG. 2), data symbols 402, and other symbols 403, null symbols 1301 are inserted.

[0173] The null symbol 1301 has an in-phase component I of zero (0) and a quadrature component Q of zero (0). Note that although it is called a "null symbol" here, it is not limited to this name.

[0174] 13, null symbols are inserted into carrier 19. Note that the method of inserting null symbols is not limited to the configuration shown in FIG. 13, and for example, null symbols may be inserted at a specific time, at a specific frequency and time domain, continuously in the time and frequency domain, or discretely in the time and frequency domain.

[0175] FIG. 14 shows a frame configuration different from that of FIG. 5 of transmission signal 108_B in FIG. 1. In FIG. 14, components that operate in the same way as in FIG. 5 are assigned the same numbers. In FIG. 14, the horizontal axis is frequency (carrier) and the vertical axis is time. As in FIG. 5, a multi-carrier transmission method such as OFDM is used, so symbols exist in the carrier direction. As in FIG. 5, FIG. 14 shows symbols of all carriers. As in FIG. 5, FIG. 14 shows symbols from time $1 to time $11.

[0176] In FIG. 14, in addition to pilot symbols 501 (pilot signals 251B in FIG. 2), data symbols 502, and other symbols 503, null symbols 1301 are inserted.

[0177] The null symbol 1301 has an in-phase component I of zero (0) and a quadrature component Q of zero (0). Note that although it is called a "null symbol" here, it is not limited to this name.

[0178] 14, null symbols are inserted into carrier 19. Note that the method of inserting null symbols is not limited to the configuration shown in FIG. 14, and for example, null symbols may be inserted at a specific time, at a specific frequency and time domain, continuously in the time and frequency domain, or discretely in the time and frequency domain.

[0179] When a symbol exists on carrier A, time $B in Figure 13 and a symbol exists on carrier A, time $B in Figure 14, the symbol on carrier A, time $B in Figure 13 and the symbol on carrier A, time $B in Figure 14 are transmitted at the same time and on the same frequency. Note that the frame structures in Figures 13 and 14 are merely examples.

[0180] The other symbols in Figures 13 and 14 are symbols corresponding to "preamble signal 252 and control information symbol signal 253 in Figure 2", and therefore, when other symbols 503 in Figure 14 at the same time and on the same frequency (same carrier) as other symbols 403 in Figure 13 transmit control information, they transmit the same data (same control information).

[0181] It is assumed that the receiving device receives the frame in Figure 13 and the frame in Figure 14 simultaneously, but the receiving device can obtain the data transmitted by the transmitting device even if it receives the frame in Figure 13 or the frame in Figure 14.

[0182] Phase changer 209B receives baseband signal 208B and control signal 200, changes the phase of baseband signal 208B based on control signal 200, and outputs phase-changed signal 210B. Baseband signal 208B is a function of symbol number i, expressed as x'(i). Then, phase-changed signal 210B(x(i)) is expressed as x(i)=e j×ε(i) ×x'(i), where i is an integer equal to or greater than 0, and j is an imaginary unit. The operation of the phase changer 209B may be CDD or CSD as described in Non-Patent Document 2 and Non-Patent Document 3.

[0183] Then, the phase changer 209B performs a phase change on symbols present in the frequency axis direction. That is, the phase changer 209B performs a phase change on data symbols, pilot symbols, control information symbols, etc. At this time, null symbols can also be considered to be targets of phase change. Therefore, the symbols targeted by symbol number i are data symbols, pilot symbols, control information symbols, preambles (other symbols), null symbols, etc.

[0184] However, because the in-phase component I is zero (0) and the quadrature component Q is zero (0), even if a phase change is performed on a null symbol, the signal before and after the phase change are the same. Therefore, it is also possible to interpret that a null symbol is not subject to phase change. In the case of FIG. 2, phase change unit 209B performs a phase change on baseband signal 208B, and therefore performs a phase change on each symbol shown in FIG. 14. When a phase change is performed on baseband signal 208A in FIG. 2, a phase change is performed on each symbol shown in FIG. 13. This point will be explained later.

[0185] Therefore, in the frame of Fig. 14, the phase change unit 209B of Fig. 2 applies a phase change to all symbols (other symbols 503) of all carriers at time $1. However, the handling of the phase change of the null symbol 1301 is as explained above.

[0186] Similarly, the phase change unit 209B in FIG. 2 performs phase change on the following symbols: "All symbols of all carriers at time $2 (other symbols 503)" "All symbols of all carriers at time $3 (other symbols 503)" "All symbols of all carriers at time $4 (other symbols 503)" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $5" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $6" "All symbols of all carriers at time $7 (pilot symbol 501 or data symbol 502)" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $8" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $9" "All symbols of all carriers at time $10 (pilot symbol 501 or data symbol 502)" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $11", however, the handling of the phase change of the null symbol 1301 is as explained above. The following description will be omitted.

[0187] The phase change value in phase changer 209B is represented as Ω(i). Baseband signal 208B is x'(i), and phase-changed signal 210B is x(i). Therefore, x(i) = Ω(i) × x'(i) holds. For example, the phase change value is set as follows: Q is an integer equal to or greater than 2, and Q is the period of the phase change.

[0188]

number

[0189] j is the imaginary unit. However, Equation (38) is merely an example and is not limited to this.

[0190] For example, Ω(i) may be set to perform a phase change with a period Q.

[0191] 5 and 14, the same phase change value may be given to the same carrier, and the phase change value may be set for each carrier. For carrier 1 in Figures 5 and 14, the phase change value is set regardless of the time.

[0192]

number

[0193] Let's say. For carrier 2 in Figures 5 and 14, the phase change value is set regardless of the time.

[0194]

number

[0195] Let's say. For carrier 3 in Figures 5 and 14, the phase change value is set regardless of the time.

[0196]

number

[0197] Let's say. For carrier 4 in Figures 5 and 14, the phase change value is set regardless of the time.

[0198]

number

[0199] The rest of the description is omitted.

[0200] The above is an example of the operation of the phase changer 209B in FIG.

[0201] The effects obtained by the phase changer 209B in FIG. 2 will be described.

[0202] Other symbols 403, 503 in the "frames of Figs. 4 and 5" or "frames of Figs. 13 and 14" contain control information symbols. As described above, other symbol 503 in Fig. 5, which transmits control information at the same time and on the same frequency (same carrier) as other symbol 403, transmits the same data (same control information).

[0203] Now, consider the following case.

[0204] Case 2: The control information symbols are transmitted using either the antenna unit #A 109_A or the antenna unit #B 109_B in FIG.

[0205] When transmitting as in "Case 2," the number of antennas that transmit control information symbols is one, and therefore the spatial diversity gain is smaller than when "control information symbols are transmitted using both antenna unit #A 109_A and antenna unit #B 109_B," and therefore, in "Case 2," the reception quality of data is reduced even when received by the receiving device of Fig. 8. Therefore, in terms of improving the reception quality of data, it is better to "transmit control information symbols using both antenna unit #A 109_A and antenna unit #B 109_B."

[0206] Case 3: Control information symbols are transmitted using both antenna unit #A 109_A and antenna unit #B 109_B in Fig. 1. However, phase change is not performed in phase change unit 209B in Fig. 2.

[0207] When transmitting as in "Case 3," the modulated signal transmitted from antenna unit #A 109_A and the modulated signal transmitted from antenna unit #B 109_B are the same or have a specific phase shift, so depending on the radio wave propagation environment, the receiving device in Figure 8 may receive a poor signal, and both modulated signals may be affected by the same multipath. This can cause a phenomenon in which the data reception quality in the receiving device in Figure 8 deteriorates.

[0208] To mitigate this phenomenon, phase change unit 209B is provided in Fig. 2. This changes the phase in the time or frequency direction, thereby reducing the possibility of a poorly received signal in the receiving device of Fig. 8. Furthermore, since there is a high possibility that the influence of multipath on the modulated signal transmitted from antenna unit #A 109_A is different from the influence of multipath on the modulated signal transmitted from antenna unit #B 109_B, there is a high possibility that diversity gain can be obtained, thereby improving the data reception quality in the receiving device of Fig. 8.

[0209] For the above reasons, in FIG. 2, phase change section 209B is provided to change the phase.

[0210] In addition to the control information symbols, other symbols 403 and other symbols 503 include, for example, symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation, in order to demodulate and decode the control information symbols. Also, the "frames of Figures 4 and 5" or the "frames of Figures 13 and 14" include pilot symbols 401 and 501, and by using these, it is possible to demodulate and decode the control information symbols with higher accuracy.

[0211] 4 and 5 or the frames of FIGS. 13 and 14, multiple streams are transmitted using the same frequency (frequency band) and the same time, that is, MIMO transmission, by data symbols 402 and data symbols 502. To demodulate these data symbols, symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation, which are included in other symbols 403 and other symbols 503, are used.

[0212] At this time, the phases of "the symbols for signal detection, the symbols for frequency synchronization and time synchronization, and the symbols for channel estimation included in other symbols 403 and other symbols 503" are changed by phase change unit 209B as described above.

[0213] Under such circumstances, if this processing is not reflected on data symbol 402 and data symbol 502 (in the case of the above explanation, on data symbol 502), when demodulating and decoding data symbol 402 and data symbol 502 in the receiving device, demodulation and decoding must be performed that reflects the processing for the phase change performed by phase change unit 209B, and this processing is likely to become complicated. This is because the phases of "symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation, which are included in other symbols 403 and other symbols 503," have been changed by phase change unit 209B.

[0214] However, as shown in FIG. 2, when phase change section 209B performs a phase change on data symbol 402 and data symbol 502 (data symbol 502 in the above description), there is an advantage that the receiving device can easily demodulate and decode data symbol 402 and data symbol 502 using a channel estimation signal (a propagation path fluctuation estimation signal) estimated using "other symbols 403 and, which are included in other symbols 503, symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation."

[0215] In addition, as shown in FIG. 2, when phase change section 209B applies a phase change to data symbol 402 and data symbol 502 (data symbol 502 in the above description), it is possible to reduce the effect of a sudden drop in field strength on the frequency axis in multipath, which may result in an improvement in the reception quality of data for data symbol 402 and data symbol 502.

[0216] In this way, the difference between "the target symbols for which phase modification is performed by phase modification section 205B" and "the target symbols for which phase modification is performed by phase modification section 209B" is a distinctive feature.

[0217] As described above, by performing a phase change using phase change unit 205B in FIG. 2, it is possible to obtain the effect of improving the reception quality of data at the receiving device for data symbol 402 and data symbol 502, for example, in an LOS environment, and by performing a phase change using phase change unit 209B in FIG. 2, it is possible to obtain the effect of improving the reception quality at the receiving device for control information symbols included in, for example, "the frames in FIGS. 4 and 5" or "the frames in FIGS. 13 and 14", and simplifying the operations of demodulating and decoding data symbol 402 and data symbol 502.

[0218] In addition, by performing a phase change using phase change unit 205B in Figure 2, it is possible to obtain the effect of improving the reception quality of data at the receiving device for data symbol 402 and data symbol 502, for example, in an LOS environment.Furthermore, by performing a phase change on data symbol 402 and data symbol 502 using phase change unit 209B in Figure 2, the reception quality of data symbol 402 and data symbol 502 is improved.

[0219] Note that, although FIG. 2 illustrates a configuration in which phase change unit 209B is provided after insertion unit 207B and performs a phase change on baseband signal 208B, the configuration for obtaining both the effects of the phase change by phase change unit 205B and the effects of the phase change by phase change unit 209B described above is not limited to the configuration shown in FIG. 2.

[0220] For example, a modified configuration may be adopted in which phase change unit 209B is removed from the configuration of FIG. 2, baseband signal 208B output from insertion unit 207B is used as signal processed signal 106_B, phase change unit 209A that performs the same operation as phase change unit 209B is added subsequent to insertion unit 207A, and phase-changed signal 210A obtained by phase-changing baseband signal 208A by phase change unit 209A is used as signal processed signal 106_A.

[0221] Even with this configuration, as in the case of Figure 2 described above, by performing a phase change using phase change unit 205B, it is possible to obtain the effect of improving the reception quality of data at the receiving device for data symbol 402 and data symbol 502, for example, in an LOS environment, and further by performing a phase change using phase change unit 209A for data symbol 402 and data symbol 502, it is possible to obtain the effect of improving the reception quality of data symbol 402 and data symbol 502.

[0222] Furthermore, it is possible to obtain an effect that the reception quality of the control information symbols included in the "frames of FIGS. 4 and 5" or the "frames of FIGS. 13 and 14" at the receiving device is improved.

[0223] (Supplementary Note 1) In the first embodiment and the like, it has been stated that the operation of the "phase change unit B" may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. A supplementary explanation will be given on this point.

[0224] A configuration when CDD / CSD is used is shown in Fig. 15. This is a modulated signal 1501 when no cyclic delay is applied, and is represented as X[n].

[0225] A cyclic delay unit 1502_1 receives a modulated signal 1501, performs cyclic delay processing, and outputs a signal 1503_1 after the cyclic delay processing. If the signal 1503_1 after the cyclic delay processing is X1[n], X1[n] is given by the following equation.

[0226]

number

[0227] Note that δ1 is the amount of cyclic delay (δ1 is an integer greater than or equal to 0), and X[n] is composed of N samples (N is an integer greater than or equal to 2), so n is an integer greater than or equal to 0 and less than or equal to N-1. Furthermore, mod represents modulo, and "A mod B" means "the remainder when A is divided by B." ... Cyclic delay section 1502_M receives modulated signal 1501 as input, performs cyclic delay processing, and outputs signal 1503_M after cyclic delay processing. If signal 1503_M after cyclic delay processing is XM[n], XM[n] is given by the following equation.

[0228]

number

[0229] It should be noted that ΔM is the amount of cyclic delay (ΔM is an integer equal to or greater than 0), and X[n] is made up of N samples (N is an integer equal to or greater than 2), and therefore n is an integer equal to or greater than 0 and equal to or less than N−1.

[0230] Therefore, cyclic delay unit 1502_i receives modulated signal 1501 as input, performs cyclic delay processing, and outputs signal 1503_i after cyclic delay processing. If signal 1503_i after cyclic delay processing is Xi[n], Xi[n] is given by the following equation: i is an integer between 1 and M, and M is an integer greater than or equal to 1.

[0231]

number

[0232] Here, δi is the amount of cyclic delay (δi is an integer equal to or greater than 0), and X[n] is composed of N samples (N is an integer equal to or greater than 2), so n is an integer equal to or greater than 0 and equal to or less than N-1.

[0233] Then, signal 1503_i after cyclic delay processing is transmitted from antenna i. Therefore, signal 1503_1 after cyclic delay processing, ..., signal 1503_M after cyclic delay processing are transmitted from different antennas. Note that, although the above explanation has been given using a discrete signal as an example, similar processing can be performed on a continuous signal as well.

[0234] By doing so, a diversity effect can be obtained by cyclic delay, and for example, the adverse effects of delayed waves can be reduced, and the receiving device can achieve the effect of improving the reception quality of data.

[0235] For example, the phase changer 209B in FIG. 2 may be replaced with the cyclic delay unit shown in FIG. 15, and the operation of the phase changer 209B may be the same as that of the cyclic delay unit.

[0236] 2, a cyclic delay amount δ (δ is an integer equal to or greater than 0) is applied, and the input signal to phase shifter 209B is represented as Y[n]. When the output signal of phase shifter 209B is represented as Z[n], Z[n] is given by the following equation.

[0237]

number

[0238] It should be noted that Y[n] is made up of N samples (N is an integer of 2 or more), and therefore n is an integer of 0 or more and N-1 or less.

[0239] Next, the relationship between the amount of cyclic delay and phase change will be described.

[0240] For example, consider the case where CDD / CSD is applied to OFDM. When OFDM is used, the carrier arrangement is as shown in FIG.

[0241] In Figure 16, 1601 is a symbol, the horizontal axis is frequency (carrier number), and the carriers are arranged in ascending order from low to high frequency. Therefore, if the carrier with the lowest frequency is "Carrier 1," then it is followed by "Carrier 2," "Carrier 3," "Carrier 4," and so on.

[0242] Then, for example, a cyclic delay amount τ is applied in phase changer 209B in Fig. 2. Then, the phase change value Ω[i] in "carrier i" is expressed as follows:

[0243]

number

[0244] It should be noted that μ is a value that can be calculated from the amount of cyclic delay, FFT (Fast Fourier Transform) size, and the like.

[0245] If the baseband signal for "carrier i" at time t before the phase change (before the cyclic delay processing) is v'[i][t], then the signal v[i][t] for "carrier i" at time t after the phase change can be expressed as v[i][t] = Ω[i] × v'[i][t].

[0246] (Supplementary Note 2) Naturally, the embodiments and other contents described in this specification may be combined and implemented.

[0247] Furthermore, each embodiment and other contents are merely examples, and for example, even if a "modulation method, error correction coding method (error correction code to be used, code length, coding rate, etc.), control information, etc." is exemplified, it is possible to implement the same configuration even if a different "modulation method, error correction coding method (error correction code to be used, code length, coding rate, etc.), control information, etc." is applied.

[0248] Regarding the modulation method, even if a modulation method other than the modulation methods described in this disclosure is used, it is possible to implement the embodiments and other contents described in this disclosure. For example, APSK (Amplitude Phase Shift Keying) (e.g., 16APSK, 64APSK, 128APSK, 256APSK, 1024APSK, 4096APSK, etc.), PAM (Pulse Amplitude Modulation) (e.g., 4PAM, 8PAM, 16PAM, 64PAM, 128PAM, 256PAM, 1024PAM, 4096PAM, etc.), PSK (e.g., BPSK, QPSK, 8PSK, 16PSK, 64PSK, 128PSK, 256PSK, 1024PSK, 4096PSK, etc.), QAM (Quadrature Amplitude Modulation) (e.g., 4QAM, 8QAM, 16QAM, 64QAM, 128QAM, 256QAM, etc.), For each modulation method, uniform mapping or non-uniform mapping may be used.

[0249] Furthermore, the method of arranging 2, 4, 8, 16, 64, 128, 256, 1024, etc. signal points on the IQ plane (modulation methods having 2, 4, 8, 16, 64, 128, 256, 1024, etc. signal points) is not limited to the signal point arrangement method of the modulation method shown in this disclosure. Therefore, the function of outputting in-phase components and quadrature components based on a plurality of bits becomes the function of the mapping unit, and then performing precoding and phase change becomes one effective function of this disclosure.

[0250] In this disclosure, when "∀" and "∃" are present, "∀" represents a universal quantifier, and "∃" represents an existential quantifier.

[0251] Also, in this disclosure, when there is a complex plane, the unit of phase, such as argument, is "radian."

[0252] Using the complex plane, complex numbers can be expressed in polar form as polar coordinates. When a point (a, b) on the complex plane corresponds to the complex number z = a + jb (a and b are real numbers, and j is the imaginary unit), if this point is expressed as [r, θ] in polar coordinates, then a=r×cosθ, b=r×sinθ

[0253]

number

[0254] holds, r is the absolute value of z (r = |z|), and θ is the argument. And z = a + jb is r×e jθ It is expressed as follows.

[0255] In the present disclosure, the receiving device and the antenna of the terminal may be separate devices. For example, the receiving device may have an interface that inputs, via a cable, a signal received by the antenna or a signal that has been frequency-converted from the signal received by the antenna, and the receiving device performs subsequent processing.

[0256] The data and information obtained by the receiving device are then converted into video and sound, which are displayed on a display (monitor) or output from a speaker. Furthermore, the data and information obtained by the receiving device may be subjected to signal processing related to video and sound, and output from an RCA terminal (video terminal, audio terminal), USB (Universal Serial Bus), HDMI (registered trademark) (High-Definition Multimedia Interface), digital terminal, etc., provided in the receiving device. The effects of the present disclosure can be achieved without performing signal processing related to video and sound.

[0257] In the present disclosure, the transmitting device may be, for example, communication and broadcasting equipment such as a broadcast station, a base station, an access point, a terminal, a mobile phone, etc., and the receiving device may be, for example, communication equipment such as a television, a radio, a terminal, a personal computer, a mobile phone, an access point, a base station, etc. In addition, the transmitting device and receiving device in the present disclosure may be equipment having a communication function, and may be configured to be connectable via some kind of interface to a device for executing an application, such as a television, a radio, a personal computer, or a mobile phone.

[0258] In this embodiment, symbols other than data symbols, such as pilot symbols (preambles, unique words, postambles, reference symbols, etc.), control information symbols, etc. may be arranged in any manner in a frame. Here, they are called pilot symbols and control information symbols, but any naming method may be used; what is important is the function itself.

[0259] The pilot symbols may be known symbols modulated by PSK modulation in the transmitter and receiver, and the receiver uses these symbols to perform frequency synchronization, time synchronization, channel estimation (CSI (Channel State Information) estimation) (for each modulated signal), signal detection, etc. Note that by synchronizing the receiver, the receiver may be able to know the pilot symbols transmitted by the transmitter.

[0260] In addition, the control information symbols are symbols for transmitting information that needs to be transmitted to the communication partner in order to realize communication other than data (e.g., application data), such as the modulation method and error correction coding method and coding rate of the error correction coding method used in the communication, and setting information in the upper layer.

[0261] The present disclosure is not limited to the embodiments and can be implemented with various modifications. For example, in the embodiments, the case where the communication method is performed as a communication device is described, but the present disclosure is not limited to this and the communication method can also be implemented as software.

[0262] Furthermore, although the above describes a precoding switching method in a method of transmitting two modulated signals from two antennas, the present invention is not limited to this, and can also be implemented as a precoding switching method in which the precoding weight (precoding matrix) is changed in a similar manner in a method of performing precoding on four mapped signals to generate four modulated signals and transmitting them from four antennas, that is, performing precoding on N mapped signals to generate N modulated signals and transmitting them from N antennas.

[0263] In this disclosure, terms such as "precoding" and "precoding weight" are used, but the names themselves may be any name, and in this disclosure, the signal processing itself is important.

[0264] The streams s1(t) and s2(t) may transmit different data or the same data.

[0265] The single antenna shown in the drawings, both the transmitting antenna of the transmitting device and the receiving antenna of the receiving device, may be configured with multiple antennas.

[0266] The transmitting device notifies the receiving device of the transmission method (MIMO, SISO, space-time block coding, interleaving), modulation method, and error correction coding method, which are contained in the frame transmitted by the transmitting device. The receiving device changes its operation by obtaining this information.

[0267] For example, a program for executing the above-described communication method may be stored in advance in a ROM (Read Only Memory), and the program may be run by a CPU (Central Processor Unit).

[0268] In addition, a program for executing the above-mentioned communication method may be stored in a computer-readable storage medium, and the program stored in the storage medium may be recorded in the computer's RAM (Random Access Memory), causing the computer to operate in accordance with the program.

[0269] Each configuration of the above-described embodiments may be realized as an LSI (Large Scale Integration), which is typically an integrated circuit. These may be individually implemented as single chips, or may be implemented as a single chip that includes all or part of the configuration of each embodiment.

[0270] Here, we refer to LSI, but depending on the level of integration, it may also be called IC (Integrated Circuit), system LSI, super LSI, or ultra LSI. Furthermore, the method of integration is not limited to LSI, and it may be realized using dedicated circuits or general-purpose processors. It is also possible to use FPGAs (Field Programmable Gate Arrays), which can be programmed after LSI manufacturing, or reconfigurable processors, which allow the connections and settings of circuit cells within LSI to be reconfigured.

[0271] Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derivative technologies, it is natural that such technology may be used to integrate functional blocks. The application of biotechnology is also a possibility.

[0272] The present disclosure can be widely applied to wireless systems that transmit different modulated signals from multiple antennas, and can also be applied to MIMO transmission in wired communication systems with multiple transmission points (e.g., PLC (Power Line Communication) systems, optical communication systems, and DSL (Digital Subscriber Line) systems).

[0273] (Embodiment 2) In this embodiment, a method of implementing a configuration different from that shown in FIG. 2 in the first embodiment will be described.

[0274] FIG. 1 shows an example of the configuration of a transmitting device such as a base station, an access point, or a broadcasting station in this embodiment, and details have been explained in the first embodiment, so explanation will be omitted.

[0275] Signal processing unit 106 receives mapped signals 105_1 and 105_2, signal group 110, and control signal 100 as input, performs signal processing based on control signal 100, and outputs processed signals 106_A and 106_B. Here, processed signal 106_A is represented as u1(i), and processed signal 106_B is represented as u2(i). i is a symbol number, and is an integer equal to or greater than 0, for example. Details of the signal processing will be described with reference to FIG. 18.

[0276] 18 shows an example of the configuration of signal processing unit 106 in FIG. 1. Weighting combination unit (precoding unit) 203 receives mapped signal 201A (mapped signal 105_1 in FIG. 1), mapped signal 201B (mapped signal 105_2 in FIG. 1), and control signal 200 (control signal 100 in FIG. 1), performs weighting combination (precoding) based on control signal 200, and outputs weighted signal 204A and weighted signal 204B. In this case, mapped signal 201A is represented as s1(t), mapped signal 201B as s2(t), weighted signal 204A as z1(t), and weighted signal 204B as z2'(t). Note that t represents time, for example. s1(t), s2(t), z1(t), and z2'(t) are defined as complex numbers, and therefore may be real numbers.

[0277] Here, it is treated as a function of time, but it may be a function of "frequency (carrier number)", or a function of "time and frequency". It may also be a function of "symbol number". This is also the same as in the first embodiment.

[0278] The weighting and combining unit (precoding unit) 203 performs the calculation of equation (1).

[0279] Phase shifter 205B receives weighted and combined signal 204B and control signal 200 as input, and performs a phase shift on weighted and combined signal 204B based on control signal 200, outputting phase-shifted signal 206B. Phase-shifted signal 206B is represented by z2(t), which is defined as a complex number and may be a real number.

[0280] The specific operation of the phase changer 205B will be described. For example, the phase changer 205B applies a phase change of y(i) to z2'(i). Therefore, it can be expressed as z2(i) = y(i) × z2'(i), where i is the symbol number and is an integer equal to or greater than 0.

[0281] For example, the phase change value is set as shown in equation (2). N is an integer equal to or greater than 2, and N is the phase change period. Note that if N is set to an odd number equal to or greater than 3, there is a possibility that the data reception quality will improve. However, equation (2) is merely an example, and is not limited to this. Therefore, the phase change value y(i)=e j×δ(i) It is expressed as:

[0282] In this case, z1(i) and z2(i) can be expressed by equation (3). Note that δ(i) is a real number. Then, z1(i) and z2(i) are transmitted from the transmitting device at the same time and at the same frequency (same frequency band). In equation (3), the phase change value is not limited to equation (2), and for example, a method of periodically and regularly changing the phase is also possible.

[0283] As explained in the first embodiment, the (precoding) matrices in the formulas (1) and (3) can be the formulas (5) to (36), etc. However, the precoding matrices are not limited to these, and the same applies to the first embodiment.

[0284] Insertion section 207A receives weighted and combined signal 204A, pilot symbol signal pa(t) 251A, preamble signal 252, control information symbol signal 253, and control signal 200 as input, and outputs baseband signal 208A based on the frame configuration, based on the frame configuration information included in control signal 200. Here, t represents time.

[0285] Similarly, insertion unit 207B receives phase-shifted signal 206B, pilot symbol signal pb(t) 251B, preamble signal 252, control information symbol signal 253, and control signal 200 as input, and outputs baseband signal 208B based on the frame configuration, based on the frame configuration information included in control signal 200.

[0286] Phase changer 209A receives baseband signal 208A and control signal 200, changes the phase of baseband signal 208A based on control signal 200, and outputs phase-changed signal 210A. Baseband signal 208A is a function of symbol number i, expressed as x'(i). Then, phase-changed signal 210A(x(i)) is expressed as x(i)=e j×ε(i) It can be expressed as ×x'(i), where i is an integer greater than or equal to 0 and j is the imaginary unit.

[0287] As described in the first embodiment and the like, the operation of phase changer 209A may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209A performs phase change on symbols present in the frequency axis direction. That is, phase changer 209A performs phase change on data symbols, pilot symbols, control information symbols, etc.

[0288] FIG. 3 shows an example of the configuration of radio units 107_A and 107_B in FIG. 1, FIG. 4 shows the frame configuration of transmission signal 108_A in FIG. 1, and FIG. 5 shows the frame configuration of transmission signal 108_B in FIG. 1. Since detailed explanations have been given in embodiment 1, explanations will be omitted.

[0289] When a symbol exists on carrier A, time $B in Figure 4 and a symbol exists on carrier A, time $B in Figure 5, the symbol on carrier A, time $B in Figure 4 and the symbol on carrier A, time $B in Figure 5 are transmitted at the same time and on the same frequency. Note that the frame structure is not limited to Figures 4 and 5, and Figures 4 and 5 are merely examples of frame structures.

[0290] The other symbols in Figures 4 and 5 are symbols corresponding to "preamble signal 252 and control information symbol signal 253 in Figure 2", and therefore, when other symbols 503 in Figure 5 at the same time and on the same frequency (same carrier) as other symbols 403 in Figure 4 transmit control information, they transmit the same data (same control information).

[0291] It is assumed that the receiving device receives the frame in Figure 4 and the frame in Figure 5 simultaneously, but the receiving device can obtain the data transmitted by the transmitting device even if it receives the frame in Figure 4 or the frame in Figure 5.

[0292] FIG. 6 shows an example of the configuration of a portion related to control information generation for generating control information signal 253 in FIG. 2, and as detailed explanation has been given in the first embodiment, explanation thereof will be omitted.

[0293] Fig. 7 shows an example of the configuration of antenna unit #A 109_A and antenna unit #B 109_B in Fig. 1. Fig. 7 shows an example in which antenna unit #A 109_A and antenna unit #B 109_B are configured with multiple antennas, and as detailed explanations have been given in embodiment 1, explanations will be omitted.

[0294] Figure 8 shows an example of the configuration of a receiving device that receives a modulated signal when the transmitting device of Figure 1 transmits a transmission signal having the frame structure of Figures 4 and 5, for example. Since a detailed explanation has been given in embodiment 1, a detailed explanation will be omitted here.

[0295] Fig. 10 shows an example of the configuration of antenna unit #X 801X and antenna unit #Y 801Y in Fig. 8. Fig. 10 shows an example in which antenna unit #X 801X and antenna unit #Y 801Y are configured with multiple antennas, and as this was explained in detail in embodiment 1, a detailed explanation will be omitted.

[0296] Next, as shown in Fig. 1, signal processing unit 106 of the transmitting device has phase change unit 205B and phase change unit 209A inserted therein, as shown in Fig. 18. The characteristics and effects of this will be described.

[0297] As explained using Figures 4 and 5, phase change section 205B performs precoding (weighting and combining) on ​​mapped signal s1(i) 201A obtained by mapping using a first sequence and mapped signal s2(i) 201B obtained by mapping using a second sequence, and performs a phase change on one of the resulting weighted and combined signals 204A, 204B, where i is a symbol number and is an integer equal to or greater than 0.

[0298] Then, weighted and combined signal 204A and phase-shifted signal 206B are transmitted at the same frequency and at the same time. Therefore, in Figs. 4 and 5, a phase shift is performed on data symbol 502 in Fig. 5. In Fig. 18, phase shift section 205 performs a phase shift on weighted and combined signal 204B, and therefore performs a phase shift on data symbol 502 in Fig. 5. When performing a phase shift on weighted and combined signal 204A, a phase shift is performed on data symbol 402 in Fig. 4. This point will be explained later.

[0299] For example, Fig. 11 shows carrier 1 to carrier 5 and time $4 to time $6 extracted from the frame of Fig. 5. As in Fig. 5, pilot symbols 501, data symbols 502, and other symbols 503 are shown.

[0300] As described above, in the symbols shown in FIG. 11, phase change unit 205B applies phase change to the data symbols at (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6).

[0301] Therefore, the phase change value for the data symbol shown in FIG. 11 is "e j×δ15(i) " and (carrier 2, time $5) "e j×δ25(i) " and (carrier 3, time $5) is "e j×δ35(i)" and (carrier 4, time $5) is "e j×δ45(i) " and (carrier 5, time $5) is "e j×δ55(i) " and (Carrier 1, Time $6) is "e j×δ16(i) " and (carrier 2, time $6) is "e j×δ26(i) " and (carrier 4, time $6) is "e j×δ46(i) " and (carrier 5, time $6) is "e j×δ56(i) "

[0302] On the other hand, in the symbols shown in Figure 11, other symbols in (carrier 1, time $4), (carrier 2, time $4), (carrier 3, time $4), (carrier 4, time $4), and (carrier 5, time $4), and the pilot symbol in (carrier 3, time $6) are not subject to phase modification by phase modification unit 205B.

[0303] This is a characteristic feature of phase changer 205B. Note that in Fig. 4, data carriers are allocated at the "same carrier, same time" as the data symbols in (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6), which are the targets of phase change in Fig. 11.

[0304] That is, in Figure 4, (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6) are data symbols.

[0305] That is, data symbols undergoing MIMO transmission, which transmits a plurality of streams, are the targets of phase modification by phase modification section 205B.

[0306] An example of the phase change that the phase change unit 205B applies to the data symbols is a method of performing a regular phase change, a phase change with a period of N, on the data symbols, as shown in equation (2). However, the method of changing the phase of the data symbols is not limited to this.

[0307] By doing so, in an environment where direct waves are dominant, for example, an LOS environment, it is possible to obtain an effect of improving the reception quality of data at a receiving device for data symbols that are undergoing MIMO transmission in which multiple streams are transmitted. This effect will now be explained.

[0308] For example, the modulation scheme used in mapping section 104 in Fig. 1 is QPSK. Mapped signal 201A in Fig. 18 is a QPSK signal, and mapped signal 201B is also a QPSK signal. In other words, two QPSK streams are transmitted.

[0309] Then, in the signal processing unit 811 in FIG. 8, for example, 16 candidate signal points are obtained using the channel estimation signals 806_1 and 806_2. QPSK can transmit 2 bits, and a total of 4 bits are transmitted by two streams. 4 = 16 candidate signal points. Note that another 16 candidate signal points can also be obtained using channel estimation signals 808_1 and 808_2, but the explanation is similar, so the explanation will focus on the 16 candidate signal points obtained using channel estimation signals 806_1 and 806_2.

[0310] An example of this state is shown in Figure 12. In both Figures 12A and 12B, the horizontal axis is in-phase I and the vertical axis is quadrature Q, and there are 16 candidate signal points on the in-phase I-quadrature Q plane. One of the 16 candidate signal points is the signal point transmitted by the transmitting device. For this reason, they are called "16 candidate signal points."

[0311] In an environment where direct waves are dominant, for example, an LOS environment, the first case is considered as "a case where phase change unit 205B of FIG. 18 does not exist, i.e., a case where phase change is not performed by phase change unit 205B of FIG. 18."

[0312] In the "first case," no phase change is performed, which may result in the state shown in Fig. 12A. When the state shown in Fig. 12A occurs, there are areas where signal points are densely packed, such as "signal points 1201 and 1202," "signal points 1203, 1204, 1205, and 1206," and "signal points 1207 and 1208," which may result in a decrease in data reception quality in the receiving device of Fig. 8.

[0313] To overcome this phenomenon, phase shifter 205B is inserted in Fig. 18. When phase shifter 205B is inserted, symbol numbers i will have a mixture of symbol numbers where "areas where signal points are densely packed" as in Fig. 12A and symbol numbers where "the distance between signal points is long" as in Fig. 12B. To address this situation, error correction coding is introduced, making it possible to obtain high error correction capabilities, and high data reception quality can be achieved in the receiving device of Fig. 8.

[0314] 18, phase modification section 205B in Fig. 18 does not modify the phase of "pilot symbols and preambles" used for channel estimation to demodulate (detect) data symbols, such as pilot symbols and preambles. This makes it possible to achieve, for data symbols, "a mixture of symbol numbers where "areas where signal points are densely packed" as in Fig. 12A and symbol numbers where "the distance between signal points is long" as in Fig. 12B, depending on symbol number i."

[0315] However, even if phase change is performed in phase change unit 205B of FIG. 18 on "pilot symbols and preambles" for channel estimation to demodulate (detect) data symbols, such as pilot symbols and preambles, there are cases where "in data symbols, it is possible to achieve a mixture of symbol numbers where "areas where signal points are densely packed" as in FIG. 12A and symbol numbers where "the distance between signal points is long" as in FIG. 12B, depending on symbol number i."

[0316] In this case, some conditions must be imposed on the phase change of the pilot symbols and preambles. For example, a method can be considered in which a different rule is established from the rule for phase change of the data symbols, and "phase change is applied to the pilot symbols and / or preambles." For example, there is a method in which phase change is applied to the data symbols regularly with a period of N, and phase change is applied to the pilot symbols and / or preambles regularly with a period of M. N and M are integers equal to or greater than 2.

[0317] As described above, phase changer 209A receives baseband signal 208A and control signal 200 as input, changes the phase of baseband signal 208A based on control signal 200, and outputs phase-changed signal 210A. Baseband signal 208A is a function of symbol number i, expressed as x'(i). Then, phase-changed signal 210A(x(i)) is expressed as x(i)=e j×ε(i) It can be expressed as ×x'(i), where i is an integer greater than or equal to 0 and j is the imaginary unit.

[0318] The operation of phase changer 209A may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209A performs phase change on symbols present in the frequency axis direction. Phase changer 209A performs phase change on data symbols, pilot symbols, control information symbols, etc. Therefore, in this case, the symbols targeted by symbol number i are data symbols, pilot symbols, control information symbols, preambles (other symbols), etc.

[0319] In FIG. 18, phase change section 209A applies a phase change to baseband signal 208A, and therefore applies a phase change to each symbol shown in FIG.

[0320] Therefore, in the frame of FIG. 4, phase change section 209A of FIG. 18 applies phase change to all symbols (other symbols 403) of all carriers at time $1.

[0321] Similarly, the phase change unit 209A in FIG. 18 performs phase change on the following symbols: "All symbols of all carriers at time $2 (other symbols 403)" "All symbols of all carriers at time $3 (other symbols 403)" "All symbols of all carriers at time $4 (other symbols 403)" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $5" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $6" "All symbols of all carriers at time $7 (pilot symbol 401 or data symbol 402)" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $8" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $9" "All symbols of all carriers at time $10 (pilot symbol 401 or data symbol 402)" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $11"; the rest of the description is omitted.

[0322] FIG. 13 shows a frame configuration different from that of FIG. 4 of the transmission signal 108_A in FIG. 1, and as detailed explanation has been given in the first embodiment, explanation will be omitted.

[0323] FIG. 14 shows a frame configuration different from that of FIG. 5 of the transmission signal 108_B in FIG. 1, and as detailed explanation has been given in the first embodiment, explanation will be omitted.

[0324] When a symbol exists on carrier A, time $B in Figure 13 and a symbol exists on carrier A, time $B in Figure 14, the symbol on carrier A, time $B in Figure 13 and the symbol on carrier A, time $B in Figure 14 are transmitted at the same time and on the same frequency. Note that the frame structures in Figures 13 and 14 are merely examples.

[0325] The other symbols in Figures 13 and 14 are symbols equivalent to "preamble signal 252 and control information symbol signal 253 in Figure 18", and therefore, when other symbols 503 in Figure 14 at the same time and on the same frequency (same carrier) as other symbols 403 in Figure 13 transmit control information, they transmit the same data (same control information).

[0326] It is assumed that the receiving device receives the frame in Figure 13 and the frame in Figure 14 simultaneously, but the receiving device can obtain the data transmitted by the transmitting device even if it receives the frame in Figure 13 or the frame in Figure 14.

[0327] Phase shifter 209A receives baseband signal 208A and control signal 200, shifts the phase of baseband signal 208A based on control signal 200, and outputs phase-shifted signal 210A. Baseband signal 208A is represented as a function of symbol number i, denoted as x'(i), where i is an integer equal to or greater than 0.

[0328] Then, the phase-shifted signal 210A(x(i)) is expressed as x(i)=e j×ε(i) ×x'(i) (j is the imaginary unit). The operation of phase changer 209A may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209A performs phase change on symbols present in the frequency axis direction. Phase changer 209A performs phase change on data symbols, pilot symbols, control information symbols, etc.

[0329] In this case, null symbols can also be considered to be targets of phase change. Therefore, in this case, the symbols targeted by symbol number i include data symbols, pilot symbols, control information symbols, preambles (other symbols), null symbols, etc.

[0330] However, since the null symbol has an in-phase component I of zero (0) and an orthogonal component Q of zero (0), even if a phase change is performed on the null symbol, the signal before and after the phase change is the same. Therefore, it is also possible to interpret the null symbol as not being subject to phase change. In the case of Figure 18, phase change unit 209A performs a phase change on baseband signal 208A, and therefore performs a phase change on each symbol shown in Figure 13.

[0331] Therefore, in the frame of Fig. 13, the phase change unit 209A of Fig. 18 performs phase change on all symbols (other symbols 403) of all carriers at time $1. However, the handling of the phase change on the null symbol 1301 is as explained above.

[0332] Similarly, the phase change unit 209A in FIG. 18 performs phase change on the following symbols: "For all symbols of all carriers at time $2 (other symbols 403)" "For all symbols of all carriers at time $3 (other symbols 403)" "For all symbols of all carriers at time $4 (other symbols 403)" "For all symbols of all carriers at time $5 (pilot symbol 401 or data symbol 402)" "For all symbols of all carriers at time $6 (pilot symbol 401 or data symbol 402)" "For all symbols of all carriers at time $7 (pilot symbol 401 or data symbol 402)" "For all symbols of all carriers at time $8 (pilot symbol 401 or data symbol 402)" "For all symbols of all carriers at time $9 (pilot symbol 401 or data symbol 402)" "For all symbols of all carriers at time $10 (pilot symbol 401 or data symbol 402)" "For all symbols of all carriers at time $11 (pilot symbol 401 or data symbol 402)" The following times will be omitted.

[0333] However, in the above description, the handling of the phase change of the null symbol 1301 is as explained above. Descriptions of other times and carriers are omitted.

[0334] The phase change value in phase changer 209A is represented as Ω(i). Baseband signal 208A is x'(i), and phase-changed signal 210A is x(i). Therefore, x(i) = Ω(i) × x'(i) holds.

[0335] For example, the phase change value is set as shown in equation (38). Q is an integer equal to or greater than 2, and Q is the period of the phase change. j is an imaginary unit. However, equation (38) is merely an example and is not limited to this.

[0336] For example, Ω(i) may be set to perform a phase change with a period Q.

[0337] 4 and 13, the same phase change value may be given to the same carrier, and the phase change value may be set for each carrier. For carrier 1 in Figures 4 and 13, the phase change value is set to equation (39) regardless of time. For carrier 2 in Figures 4 and 13, the phase change value is set to equation (40) regardless of time. For carrier 3 in Figures 4 and 13, the phase change value is set to equation (41) regardless of time. 4 and 13, the phase change value is set to Equation (42) regardless of time. Descriptions for other carriers are omitted.

[0338] The above is an example of the operation of the phase changer 209A in FIG.

[0339] The effects obtained by the phase changing section 209A in FIG. 18 will be described.

[0340] Other symbols 403, 503 in the "frames of Figs. 4 and 5" or "frames of Figs. 13 and 14" contain control information symbols. As described above, other symbol 503 in Fig. 5, which transmits control information at the same time and on the same frequency (same carrier) as other symbol 403, transmits the same data (same control information).

[0341] Now, consider Case 2, where "control information symbols are transmitted using either antenna unit #A 109_A or antenna unit #B 109_B in FIG. 1."

[0342] When transmitting as in "Case 2," the number of antennas that transmit control information symbols is one, and therefore the spatial diversity gain is smaller than when "control information symbols are transmitted using both antenna unit #A 109_A and antenna unit #B 109_B," and therefore, in "Case 2," the reception quality of data is reduced even when received by the receiving device of Fig. 8. Therefore, in terms of improving the reception quality of data, it is better to "transmit control information symbols using both antenna unit #A 109_A and antenna unit #B 109_B."

[0343] As Case 3, consider the case where "control information symbols are transmitted using both antenna unit #A 109_A and antenna unit #B 109_B in FIG. 1, but phase change is not performed in phase change unit 209A in FIG. 18."

[0344] When transmitting as in "Case 3," the modulated signal transmitted from antenna unit #A 109_A and the modulated signal transmitted from antenna unit #B 109_B are the same or have a specific phase shift, so depending on the radio wave propagation environment, the receiving device in Figure 8 may receive a very poor signal, and both modulated signals may be affected by the same multipath. This can cause a phenomenon in which the data reception quality in the receiving device in Figure 8 deteriorates.

[0345] To alleviate this phenomenon, phase change unit 209A is provided in Fig. 18. This changes the phase in the time or frequency direction, thereby reducing the possibility of a poorly received signal in the receiving device of Fig. 8. Furthermore, since there is a high possibility that the influence of multipath on the modulated signal transmitted from antenna unit #A 109_A is different from the influence of multipath on the modulated signal transmitted from antenna unit #B 109_B, there is a high possibility that diversity gain can be obtained, thereby improving the data reception quality in the receiving device of Fig. 8.

[0346] For the above reasons, in FIG. 18, a phase change section 209A is provided to change the phase.

[0347] In addition to the control information symbols, other symbols 403 and other symbols 503 include, for example, symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation, in order to demodulate and decode the control information symbols. Also, the "frames of Figures 4 and 5" or the "frames of Figures 13 and 14" include pilot symbols 401 and 501, and by using these, it is possible to demodulate and decode the control information symbols with higher accuracy.

[0348] 4 and 5 or the frames of FIGS. 13 and 14, MIMO transmission is performed to transmit multiple streams using the same frequency (frequency band) and the same time using data symbols 402 and data symbols 502. To demodulate these data symbols, symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation, which are included in other symbols 403 and other symbols 503, are used.

[0349] At this time, the phases of "the symbols for signal detection, the symbols for frequency synchronization and time synchronization, and the symbols for channel estimation included in other symbols 403 and other symbols 503" are changed by phase change unit 209A as described above.

[0350] In such a situation, if this processing is not reflected in data symbol 402 and data symbol 502 (in the above explanation, data symbol 402) and the receiving device demodulates and decodes data symbol 402 and data symbol 502, it is necessary to perform demodulation and decoding that reflects the processing for the phase change performed by phase change unit 209A, and this processing is likely to be complicated.

[0351] This is because the phases of "symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation included in other symbols 403 and other symbols 503" have been changed by phase change unit 209A.

[0352] However, as shown in FIG. 18, when phase change section 209A performs a phase change on data symbol 402 and data symbol 502 (data symbol 402 in the case of the above explanation), there is an advantage that the receiving device can easily demodulate and decode data symbol 402 and data symbol 502 using a channel estimation signal (a propagation path fluctuation estimation signal) estimated using "other symbols 403 and, which are included in other symbols 503, symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation."

[0353] In addition, as shown in FIG. 18, when phase change section 209A applies a phase change to data symbol 402 and data symbol 502 (in the above description, to data symbol 402), the effect of a sudden drop in field strength on the frequency axis in multipath can be reduced, which may result in an improvement in the reception quality of data for data symbol 402 and data symbol 502.

[0354] In this way, the characteristic feature is that "the target symbols for which phase change is performed by phase change section 205B" and "the target symbols for which phase change is performed by phase change section 209A" are different.

[0355] As described above, by performing a phase change using phase change unit 205B in FIG. 18, it is possible to obtain the effect of improving the reception quality of data at the receiving device for data symbol 402 and data symbol 502, for example, in an LOS environment, and by performing a phase change using phase change unit 209A in FIG. 18, it is possible to obtain the effect of improving the reception quality at the receiving device for control information symbols included in, for example, "the frames in FIGS. 4 and 5" or "the frames in FIGS. 13 and 14", and simplifying the operations of demodulating and decoding data symbol 402 and data symbol 502.

[0356] In addition, by performing a phase change using phase change unit 205B in Figure 18, it is possible to obtain the effect of improving the reception quality of data at the receiving device for data symbol 402 and data symbol 502, for example, in an LOS environment, and further, by performing a phase change on data symbol 402 and data symbol 502 using phase change unit 209A in Figure 18, the reception quality of data symbol 402 and data symbol 502 is improved.

[0357] It should be noted that Q in equation (38) may be an integer equal to or less than −2, and in this case, the period of phase change is the absolute value of Q. This point can also be applied to other embodiments.

[0358] (Embodiment 3) In this embodiment, a method of implementing a configuration different from that shown in FIG. 2 in the first embodiment will be described.

[0359] FIG. 1 shows an example of the configuration of a transmitting device such as a base station, an access point, or a broadcasting station in this embodiment, and details have been explained in the first embodiment, so explanation will be omitted.

[0360] Signal processing unit 106 receives mapped signals 105_1 and 105_2, signal group 110, and control signal 100 as input, performs signal processing based on control signal 100, and outputs processed signals 106_A and 106_B. Here, processed signal 106_A is represented as u1(i), and processed signal 106_B is represented as u2(i). i is a symbol number, and is an integer equal to or greater than 0, for example. Details of the signal processing will be described with reference to FIG. 19.

[0361] Fig. 19 shows an example of the configuration of signal processing unit 106 in Fig. 1. Weighting combination unit (precoding unit) 203 receives mapped signal 201A (mapped signal 105_1 in Fig. 1), mapped signal 201B (mapped signal 105_2 in Fig. 1), and control signal 200 (control signal 100 in Fig. 1), performs weighting combination (precoding) based on control signal 200, and outputs weighted signal 204A and weighted signal 204B.

[0362] In this case, mapped signal 201A is represented as s1(t), mapped signal 201B as s2(t), weighted signal 204A as z1(t), and weighted signal 204B as z2'(t). Note that t is, for example, time. s1(t), s2(t), z1(t), and z2'(t) are defined as complex numbers, and therefore may also be real numbers.

[0363] Here, it is treated as a function of time, but it may be a function of "frequency (carrier number)", or a function of "time and frequency". It may also be a function of "symbol number". This is also the same as in the first embodiment.

[0364] The weighting and combining unit (precoding unit) 203 performs the calculation of equation (1).

[0365] Phase shifter 205B receives weighted and combined signal 204B and control signal 200 as input, and performs a phase shift on weighted and combined signal 204B based on control signal 200, outputting phase-shifted signal 206B. Phase-shifted signal 206B is represented by z2(t), which is defined as a complex number and may also be a real number.

[0366] The specific operation of the phase changer 205B will be described. For example, the phase changer 205B applies a phase change of y(i) to z2'(i). Therefore, it can be expressed as z2(i) = y(i) × z2'(i), where i is the symbol number and is an integer equal to or greater than 0.

[0367] For example, the phase change value is set as shown in equation (2). N is an integer equal to or greater than 2, and N is the phase change period. If N is set to an odd number equal to or greater than 3, there is a possibility that the data reception quality will improve. However, equation (2) is merely an example, and is not limited to this. Therefore, the phase change value y(i)=e j×δ(i) It is expressed as:

[0368] In this case, z1(i) and z2(i) can be expressed by equation (3). Note that δ(i) is a real number. Then, z1(i) and z2(i) are transmitted from the transmitting device at the same time and at the same frequency (same frequency band). In equation (3), the phase change value is not limited to equation (2), and for example, a method of periodically and regularly changing the phase is also possible.

[0369] As explained in the first embodiment, the (precoding) matrices in the formulas (1) and (3) can be the formulas (5) to (36), etc. However, the precoding matrices are not limited to these, and the same applies to the first embodiment.

[0370] Insertion section 207A receives weighted and combined signal 204A, pilot symbol signal pa(t) 251A, preamble signal 252, control information symbol signal 253, and control signal 200 as input, and outputs baseband signal 208A based on the frame configuration, based on the frame configuration information included in control signal 200. t indicates time.

[0371] Similarly, insertion unit 207B receives phase-shifted signal 206B, pilot symbol signal pb(t) 251B, preamble signal 252, control information symbol signal 253, and control signal 200 as input, and outputs baseband signal 208B based on the frame configuration, based on the frame configuration information included in control signal 200.

[0372] Phase changer 209A receives baseband signal 208A and control signal 200, changes the phase of baseband signal 208A based on control signal 200, and outputs phase-changed signal 210A. Baseband signal 208A is a function of symbol number i, expressed as x'(i). Then, phase-changed signal 210A(x(i)) is expressed as x(i)=e j×ε(i) It is expressed as ×x'(i), where i is an integer greater than or equal to 0, and j is the imaginary unit.

[0373] As described in the first embodiment and the like, the operation of phase changer 209A may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209A performs phase change on symbols present in the frequency axis direction. That is, phase changer 209A performs phase change on data symbols, pilot symbols, control information symbols, etc.

[0374] Phase changer 209B receives baseband signal 208B and control signal 200, changes the phase of baseband signal 208B based on control signal 200, and outputs phase-changed signal 210B. Baseband signal 208B is a function of symbol number i, expressed as y'(i). Then, phase-changed signal 210B(y(i)) is expressed as y(i)=e j×τ(i)×y'(i), where i is an integer greater than or equal to 0 and j is the imaginary unit.

[0375] As explained in the first embodiment and the like, the operation of phase changer 209B may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209B then performs phase change on symbols present in the frequency axis direction. That is, phase changer 209B performs phase change on data symbols, pilot symbols, control information symbols, etc.

[0376] The characteristic feature here is that the phase change method using ε(i) is different from the phase change method using τ(i), or that the value of the CDD / CSD cyclic delay amount set by phase change unit 209A is different from the value of the CDD / CSD cyclic delay amount set by phase change unit 209B.

[0377] FIG. 3 shows an example of the configuration of the radio units 107_A and 107_B in FIG. 1, and as detailed explanation has been given in the first embodiment, the explanation will be omitted.

[0378] FIG. 4 shows the frame structure of the transmission signal 108_A in FIG. 1, and as detailed explanation has been given in the first embodiment, the explanation will be omitted.

[0379] FIG. 5 shows the frame structure of the transmission signal 108_B in FIG. 1, and as detailed explanation has been given in the first embodiment, the explanation will be omitted.

[0380] When a symbol exists on carrier A, time $B in Figure 4 and a symbol exists on carrier A, time $B in Figure 5, the symbol on carrier A, time $B in Figure 4 and the symbol on carrier A, time $B in Figure 5 are transmitted at the same time and on the same frequency. Note that the frame structure is not limited to Figures 4 and 5, and Figures 4 and 5 are merely examples of frame structures.

[0381] The other symbols in Figures 4 and 5 are symbols corresponding to "preamble signal 252 and control information symbol signal 253 in Figure 2", and therefore, when other symbols 503 in Figure 5 at the same time and on the same frequency (same carrier) as other symbols 403 in Figure 4 transmit control information, they transmit the same data (same control information).

[0382] It is assumed that the receiving device receives the frame in Figure 4 and the frame in Figure 5 simultaneously, but the receiving device can obtain the data transmitted by the transmitting device even if it receives the frame in Figure 4 or the frame in Figure 5.

[0383] FIG. 6 shows an example of the configuration of a portion related to control information generation for generating control information signal 253 in FIG. 2, and as detailed explanation has been given in the first embodiment, explanation thereof will be omitted.

[0384] Fig. 7 shows an example of the configuration of antenna unit #A 109_A and antenna unit #B 109_B in Fig. 1, in which antenna unit #A 109_A and antenna unit #B 109_B are configured with multiple antennas. Fig. 7 has been explained in detail in the first embodiment, so its explanation will be omitted.

[0385] Figure 8 shows an example of the configuration of a receiving device that receives a modulated signal when the transmitting device of Figure 1 transmits a transmission signal having the frame structure of Figures 4 and 5, for example. Since a detailed explanation has been given in embodiment 1, a detailed explanation will be omitted here.

[0386] Fig. 10 shows an example of the configuration of antenna unit #X 801X and antenna unit #Y 801Y in Fig. 8. Fig. 10 shows an example in which antenna unit #X 801X and antenna unit #Y 801Y are configured with multiple antennas. Fig. 10 has been explained in detail in embodiment 1, so further explanation will be omitted.

[0387] Next, in Fig. 19, phase change unit 205B and phase change units 209A and 209B are inserted into signal processing unit 106 of the transmitting device as in Fig. 1. The features and effects of this will be described.

[0388] As explained using Figures 4 and 5, phase change section 205B performs precoding (weighting and combining) on ​​mapped signal s1(i) 201A obtained by mapping using a first sequence and mapped signal s2(i) 201B obtained by mapping using a second sequence, and performs a phase change on one of the resulting weighted and combined signals 204A, 204B, where i is a symbol number and is an integer equal to or greater than 0.

[0389] Then, weighted and combined signal 204A and phase-shifted signal 206B are transmitted at the same frequency and at the same time. Therefore, in Figs. 4 and 5, a phase shift is performed on data symbol 502 in Fig. 5. In Fig. 19, phase shift section 205 performs a phase shift on weighted and combined signal 204B, and therefore performs a phase shift on data symbol 502 in Fig. 5. When performing a phase shift on weighted and combined signal 204A, a phase shift is performed on data symbol 402 in Fig. 4. This point will be explained later.

[0390] For example, Fig. 11 shows carrier 1 to carrier 5 and time $4 to time $6 extracted from the frame in Fig. 5. Note that Fig. 11 shows pilot symbols 501, data symbols 502, and other symbols 503, just like Fig. 5.

[0391] As described above, in the symbols shown in FIG. 11, phase change unit 205B applies phase change to the data symbols at (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6).

[0392] Therefore, the phase change value for the data symbol shown in FIG. 11 is "e j×δ15(i) " and (carrier 2, time $5) "e j×δ25(i) " and (carrier 3, time $5) is "e j×δ35(i) " and (carrier 4, time $5) is "e j×δ45(i) " and (carrier 5, time $5) is "e j×δ55(i) " and (Carrier 1, Time $6) is "e j×δ16(i) " and (carrier 2, time $6) is "e j×δ26(i) " and (carrier 4, time $6) is "e j×δ46(i) " and (carrier 5, time $6) is "e j×δ56(i) "

[0393] On the other hand, in the symbols shown in Figure 11, other symbols in (carrier 1, time $4), (carrier 2, time $4), (carrier 3, time $4), (carrier 4, time $4), and (carrier 5, time $4), and the pilot symbol in (carrier 3, time $6) are not subject to phase modification by phase modification unit 205B.

[0394] This is a characteristic feature of phase changer 205B. Note that, as shown in Fig. 4, data carriers are allocated at the "same carrier, same time" as the data symbols in (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6), which are the targets of phase change in Fig. 11.

[0395] That is, in Figure 4, (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6) are data symbols.

[0396] That is, data symbols that are transmitted through MIMO transmission, that is, multiple streams, are the targets of phase modification by phase modification section 205B.

[0397] An example of the phase change that the phase change unit 205B applies to the data symbols is a method of performing a regular phase change on the data symbols, for example, a phase change with a period of N, as shown in equation (2). However, the method of changing the phase of the data symbols is not limited to this.

[0398] By doing so, in an environment where direct waves are dominant, for example, an LOS environment, it is possible to obtain an effect of improving the reception quality of data at a receiving device performing MIMO transmission, that is, transmitting multiple streams of data symbols. This effect will now be explained.

[0399] For example, the modulation scheme used in mapping section 104 in Fig. 1 is QPSK. Mapped signal 201A in Fig. 19 is a QPSK signal, and mapped signal 201B is also a QPSK signal. In other words, two QPSK streams are transmitted.

[0400] Then, in the signal processing unit 811 in FIG. 8, for example, 16 candidate signal points are obtained using the channel estimation signals 806_1 and 806_2. QPSK can transmit 2 bits, and a total of 4 bits are transmitted by two streams. 4 = 16 candidate signal points.

[0401] It should be noted that another 16 candidate signal points can be obtained using channel estimation signals 808_1 and 808_2, but the explanation would be similar, so we will focus on the 16 candidate signal points obtained using channel estimation signals 806_1 and 806_2 and proceed with the explanation.

[0402] An example of this state is shown in Figures 12A and 12B. In both cases, the horizontal axis is in-phase I and the vertical axis is quadrature Q, and there are 16 candidate signal points on the in-phase I-quadrature Q plane. One of the 16 candidate signal points is the signal point transmitted by the transmitting device. For this reason, they are called "16 candidate signal points."

[0403] In an environment where direct waves are dominant, for example, an LOS environment, the first case is considered as "a case where phase change unit 205B of FIG. 19 does not exist, that is, a case where phase change is not performed by phase change unit 205B of FIG. 19."

[0404] In the "first case," no phase change is performed, which may result in the state shown in Fig. 12A. When the state shown in Fig. 12A occurs, there are areas where signal points are densely packed, such as "signal points 1201 and 1202," "signal points 1203, 1204, 1205, and 1206," and "signal points 1207 and 1208," which may result in a decrease in data reception quality in the receiving device of Fig. 8.

[0405] To overcome this phenomenon, phase shifter 205B is inserted in Fig. 19. When phase shifter 205B is inserted, symbol numbers i will have a mixture of symbol numbers where "areas where signal points are densely packed" as in Fig. 12A and symbol numbers where "the distance between signal points is long" as in Fig. 12B. To address this situation, error correction coding is introduced, making it possible to obtain high error correction capabilities and high data reception quality in the receiving device of Fig. 8.

[0406] 19, phase modification section 205B in Fig. 19 does not modify the phase of "pilot symbols and preambles" used for channel estimation to demodulate (detect) data symbols, such as pilot symbols and preambles. This makes it possible to achieve, in data symbols, "a mixture of symbol numbers where "areas where signal points are densely packed" as in Fig. 12A and symbol numbers where "the distance between signal points is long" as in Fig. 12B, depending on symbol number i."

[0407] However, even if phase change is performed in phase change unit 205B of FIG. 19 on "pilot symbols and preambles" for channel estimation to demodulate (detect) data symbols, such as pilot symbols and preambles, there are cases where "in data symbols, it is possible to achieve a mixture of symbol numbers where "areas where signal points are densely packed" as in FIG. 12A and symbol numbers where "the distance between signal points is long" as in FIG. 12B, depending on symbol number i."

[0408] In this case, some conditions must be imposed on the phase change of the pilot symbols and preambles. For example, a method can be considered in which a different rule is established from the rule for phase change of the data symbols, and "phase change is applied to the pilot symbols and / or preambles." For example, there is a method in which phase change is applied to the data symbols regularly with a period of N, and phase change is applied to the pilot symbols and / or preambles regularly with a period of M. N and M are integers equal to or greater than 2.

[0409] As described above, phase changer 209A receives baseband signal 208A and control signal 200 as input, changes the phase of baseband signal 208A based on control signal 200, and outputs phase-changed signal 210A. Baseband signal 208A is a function of symbol number i, expressed as x'(i). Then, phase-changed signal 210A(x(i)) is expressed as x(i)=e j×ε(i) It can be expressed as ×x'(i), where i is an integer greater than or equal to 0 and j is the imaginary unit.

[0410] The operation of phase changer 209A may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209A performs phase change on symbols present in the frequency axis direction. Phase changer 209A performs phase change on data symbols, pilot symbols, control information symbols, etc. Therefore, in this case, the symbols targeted by symbol number i are data symbols, pilot symbols, control information symbols, preambles (other symbols), etc.

[0411] In the case of FIG. 19, phase change section 209A applies a phase change to baseband signal 208A, and therefore applies a phase change to each symbol shown in FIG.

[0412] Therefore, in the frame of FIG. 4, phase change section 209A of FIG. 19 applies phase change to all symbols (other symbols 403) of all carriers at time $1.

[0413] Similarly, the phase change unit 209A in FIG. 19 performs phase change on the following symbols: "All symbols of all carriers at time $2 (other symbols 403)" "All symbols of all carriers at time $3 (other symbols 403)" "All symbols of all carriers at time $4 (other symbols 403)" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $5" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $6" "All symbols of all carriers at time $7 (pilot symbol 401 or data symbol 402)" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $8" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $9" "All symbols of all carriers at time $10 (pilot symbol 401 or data symbol 402)" "All symbols (pilot symbol 401 or data symbol 402) of all carriers at time $11"; other times and carriers are omitted.

[0414] As described above, phase changer 209B receives baseband signal 208B and control signal 200 as input, changes the phase of baseband signal 208B based on control signal 200, and outputs phase-changed signal 210B. Baseband signal 208B is a function of symbol number i, expressed as y'(i). Then, phase-changed signal y(i) 210B is expressed as y(i)=e j×τ(i) ×y'(i), where i is an integer greater than or equal to 0 and j is the imaginary unit.

[0415] The operation of phase changer 209B may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209B performs phase change on symbols present in the frequency axis direction. Phase changer 209B performs phase change on data symbols, pilot symbols, control information symbols, etc.

[0416] Therefore, in this case, the symbols targeted by symbol number i are data symbols, pilot symbols, control information symbols, preambles (other symbols), etc. In the case of Fig. 19, phase change unit 209B applies a phase change to baseband signal 208B, and therefore applies a phase change to each symbol shown in Fig. 5.

[0417] Therefore, in the frame of FIG. 5, phase change section 209B of FIG. 19 applies phase change to all symbols (other symbols 503) of all carriers at time $1.

[0418] Similarly, the phase change unit 209B in FIG. 19 performs phase change on the following symbols: "All symbols of all carriers at time $2 (other symbols 503)" "All symbols of all carriers at time $3 (other symbols 503)" "All symbols of all carriers at time $4 (other symbols 503)" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $5" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $6" "All symbols of all carriers at time $7 (pilot symbol 501 or data symbol 502)" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $8" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $9" "All symbols of all carriers at time $10 (pilot symbol 501 or data symbol 502)" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $11"; descriptions of other times and carriers are omitted.

[0419] FIG. 13 shows a frame configuration different from that of FIG. 4 of the transmission signal 108_A in FIG. 1, and as detailed explanation has been given in the first embodiment, explanation will be omitted.

[0420] FIG. 14 shows a frame configuration different from that of FIG. 5 of the transmission signal 108_B in FIG. 1, and as detailed explanation has been given in the first embodiment, explanation will be omitted.

[0421] When a symbol exists on carrier A, time $B in Figure 13 and a symbol exists on carrier A, time $B in Figure 14, the symbol on carrier A, time $B in Figure 13 and the symbol on carrier A, time $B in Figure 14 are transmitted at the same time and on the same frequency. Note that the frame structures in Figures 13 and 14 are merely examples.

[0422] The other symbols in Figures 13 and 14 are symbols equivalent to "preamble signal 252 and control information symbol signal 253 in Figure 19", and therefore, when other symbols 503 in Figure 14 at the same time and on the same frequency (same carrier) as other symbols 403 in Figure 13 transmit control information, they transmit the same data (same control information).

[0423] It is assumed that the receiving device receives the frame in Figure 13 and the frame in Figure 14 simultaneously, but the receiving device can obtain the data transmitted by the transmitting device even if it receives the frame in Figure 13 or the frame in Figure 14.

[0424] Phase changer 209A receives baseband signal 208A and control signal 200, changes the phase of baseband signal 208A based on control signal 200, and outputs phase-changed signal 210A. Baseband signal 208A is a function of symbol number i, expressed as x'(i). Then, phase-changed signal 210A(x(i)) is expressed as x(i)=e j×ε(i) It is expressed as ×x'(i), where i is an integer greater than or equal to 0, and j is the imaginary unit.

[0425] The operation of phase changer 209A may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209A performs phase change on symbols present in the frequency axis direction. Phase changer 209A performs phase change on data symbols, pilot symbols, control information symbols, etc. At this time, null symbols can also be considered to be targets of phase change. Therefore, in this case, the symbols targeted by symbol number i are data symbols, pilot symbols, control information symbols, preambles (other symbols), null symbols, etc.

[0426] However, even if a phase change is performed on a null symbol, the signal before and after the phase change is the same because the null symbol has an in-phase component I of zero (0) and a quadrature component Q of zero (0). Therefore, it can be interpreted that the null symbol is not subject to phase change.

[0427] In the case of FIG. 19, phase change section 209A applies a phase change to baseband signal 208A, and therefore applies a phase change to each symbol shown in FIG.

[0428] Therefore, in the frame of Fig. 13, the phase change unit 209A of Fig. 19 applies a phase change to all symbols (other symbols 403) of all carriers at time $1. However, the handling of the phase change of the null symbol 1301 is as explained above.

[0429] Similarly, the phase change unit 209A in FIG. 19 performs phase change on the following symbols: "All symbols of all carriers at time $2 (other symbols 403)" "All symbols of all carriers at time $3 (other symbols 403)" "All symbols of all carriers at time $4 (other symbols 403)" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $5" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $6" "All symbols of all carriers at time $7 (pilot symbol 401 or data symbol 402)" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $8" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $9" "All symbols of all carriers at time $10 (pilot symbol 401 or data symbol 402)" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $11", however, the handling of the phase change of the null symbol 1301 at all times and all carriers is as explained above. Descriptions of times and carriers other than those mentioned above are omitted.

[0430] The phase change value in phase changer 209A is represented as Ω(i). Baseband signal 208A is x'(i), and phase-changed signal 210A is x(i). Therefore, x(i) = Ω(i) × x'(i) holds.

[0431] For example, the phase change value is set as shown in equation (38). Q is an integer equal to or greater than 2, and Q is the period of the phase change. j is an imaginary unit. However, equation (38) is merely an example and is not limited to this.

[0432] For example, Ω(i) may be set to perform a phase change with a period Q.

[0433] 4 and 13, the same phase change value may be given to the same carrier, and the phase change value may be set for each carrier. For carrier 1 in Figures 4 and 13, the phase change value is set to equation (39) regardless of time. For carrier 2 in Figures 4 and 13, the phase change value is set to equation (40) regardless of time. For carrier 3 in Figures 4 and 13, the phase change value is set to equation (41) regardless of time. 4 and 13, the phase change value is set to Equation (42) regardless of time. Descriptions of carriers other than those mentioned above are omitted.

[0434] The above is an example of the operation of the phase changer 209A in FIG.

[0435] Phase changer 209B receives baseband signal 208B and control signal 200, changes the phase of baseband signal 208B based on control signal 200, and outputs phase-changed signal 210B. Baseband signal 208B is a function of symbol number i, expressed as y'(i). Then, phase-changed signal 210B(y(i)) is expressed as y(i)=e j×τ(i) It can be expressed as ×y'(i), where i is an integer greater than or equal to 0, and j is the imaginary unit.

[0436] The operation of phase changer 209B may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209B performs phase change on symbols present in the frequency axis direction. Phase changer 209B performs phase change on data symbols, pilot symbols, control information symbols, etc. At this time, null symbols can also be considered to be targets for phase change.

[0437] Therefore, in this case, the symbol that is the target of symbol number i is a data symbol, a pilot symbol, a control information symbol, a preamble (other symbols), a null symbol, and so on.

[0438] However, since the null symbol has an in-phase component I of zero (0) and a quadrature component Q of zero (0), even if a phase change is performed on the null symbol, the signal before and after the phase change is the same. Therefore, it is also possible to interpret the null symbol as not being subject to phase change.

[0439] In the case of FIG. 19, phase change section 209B applies a phase change to baseband signal 208B, and therefore applies a phase change to each symbol shown in FIG.

[0440] Therefore, in the frame of Fig. 14, the phase change unit 209B of Fig. 19 applies phase change to all symbols (other symbols 503) of all carriers at time $1. However, the handling of the phase change of the null symbol 1301 is as explained above.

[0441] Similarly, the phase change unit 209B in FIG. 19 performs phase change on the following symbols: "All symbols of all carriers at time $2 (other symbols 503)" "All symbols of all carriers at time $3 (other symbols 503)" "All symbols of all carriers at time $4 (other symbols 503)" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $5" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $6" "All symbols of all carriers at time $7 (pilot symbol 501 or data symbol 502)" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $8" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $9" "All symbols of all carriers at time $10 (pilot symbol 501 or data symbol 502)" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $11", however, the handling of the phase change of the null symbol 1301 for all times and all carriers is as explained above. Descriptions of times and carriers other than those mentioned above are omitted.

[0442] The phase change value in phase changer 209B is represented as Ω(i). Baseband signal 208B is y'(i), and phase-changed signal 210B is y(i). Therefore, y(i) = Δ(i) × y'(i) holds.

[0443] For example, the phase change value is set as follows: where R is an integer equal to or greater than 2, and R is the period of the phase change. It is preferable that the values ​​of Q and R in equation (38) are different.

[0444]

number

[0445] j is the imaginary unit. However, Equation (49) is merely an example and is not limited to this.

[0446] For example, Δ(i) may be set to change the phase to have a period R.

[0447] The phase change methods of phase changer 209A and phase changer 209B are different. For example, the cycles may be the same or different.

[0448] 5 and 14, the same phase change value may be given to the same carrier, and the phase change value may be set for each carrier. For carrier 1 in Figures 5 and 14, the phase change value is set to equation (39) regardless of time. For carrier 2 in Figures 5 and 14, the phase change value is set to equation (40) regardless of time. For carrier 3 in Figures 5 and 14, the phase change value is set to equation (41) regardless of time. 5 and 14, the phase change value is set to Equation (42) regardless of time. Descriptions of carriers other than those mentioned above are omitted.

[0449] Although the phase change methods are written as equations (39), (40), (41), and (42), the phase change methods of phase change unit 209A and phase change unit 209B are different.

[0450] The above is an example of the operation of the phase changer 209B in FIG.

[0451] The effects obtained by the phase change units 209A and 209B in FIG. 19 will be described.

[0452] Other symbols 403, 503 in the "frames of Figs. 4 and 5" or "frames of Figs. 13 and 14" contain control information symbols. As described above, other symbol 503 in Fig. 5, which transmits control information at the same time and on the same frequency (same carrier) as other symbol 403, transmits the same data (same control information).

[0453] Now, consider Case 2, where "control information symbols are transmitted using either antenna unit #A 109_A or antenna unit #B 109_B in FIG. 1."

[0454] When transmitting as in "Case 2," the number of antennas that transmit control information symbols is one, so the spatial diversity gain is smaller than when "control information symbols are transmitted using both antenna unit #A 109_A and antenna unit #B 109_B," and therefore, in "Case 2," the reception quality of data is reduced even when received by the receiving device of Fig. 8. Therefore, in terms of improving the reception quality of data, it is better to "transmit control information symbols using both antenna unit #A 109_A and antenna unit #B 109_B."

[0455] Case 3 is considered where "control information symbols are transmitted using both antenna unit #A 109_A and antenna unit #B 109_B in FIG. 1, but phase change is not performed in phase change units 209A and 209B in FIG. 19."

[0456] When transmitting as in "Case 3," the modulated signal transmitted from antenna unit #A 109_A and the modulated signal transmitted from antenna unit #B 109_B are the same or have a specific phase shift, so depending on the radio wave propagation environment, the receiving device in Figure 8 may receive a very poor signal, and both modulated signals may be affected by the same multipath. This can cause a phenomenon in which the data reception quality in the receiving device in Figure 8 deteriorates.

[0457] To alleviate this phenomenon, phase change units 209A and 209B are provided in Fig. 19. This changes the phase in the time or frequency direction, thereby reducing the possibility of a poorly received signal in the receiving device of Fig. 8. Furthermore, since there is a high possibility that the influence of multipath on the modulated signal transmitted from antenna unit #A 109_A is different from the influence of multipath on the modulated signal transmitted from antenna unit #B 109_B, there is a high possibility that diversity gain can be obtained, thereby improving the data reception quality in the receiving device of Fig. 8.

[0458] For the above reasons, in FIG. 19, phase change sections 209A and 209B are provided to change the phase.

[0459] In addition to the control information symbols, other symbols 403 and other symbols 503 include, for example, symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation, in order to demodulate and decode the control information symbols. Also, the "frames of Figures 4 and 5" or the "frames of Figures 13 and 14" include pilot symbols 401 and 501, and by using these, it is possible to demodulate and decode the control information symbols with higher accuracy.

[0460] 4 and 5 or the frames of FIGS. 13 and 14, multiple streams are transmitted using the same frequency (frequency band) and the same time, that is, MIMO transmission, by data symbols 402 and data symbols 502. To demodulate these data symbols, symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation, which are included in other symbols 403 and other symbols 503, are used.

[0461] At this time, the phases of "symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation included in other symbols 403 and other symbols 503" are changed by phase change units 209A and 209B as described above.

[0462] Under such circumstances, if this processing is not reflected in data symbols 402 and 502, when demodulating and decoding data symbols 402 and 502 in the receiving device, demodulation and decoding must be performed that reflects the processing for the phase change performed by phase change units 209A and 209B, and this processing is likely to become complicated. This is because the phases of "symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation, which are included in other symbols 403 and other symbols 503," have been changed by phase change units 209A and 209B.

[0463] However, as shown in FIG. 19, when phase change units 209A and 209B change the phase of data symbol 402 and data symbol 502, the receiving device can easily demodulate and decode data symbol 402 and data symbol 502 using a channel estimation signal (a propagation path fluctuation estimation signal) estimated using "other symbols 403 and, which are included in other symbols 503, symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation."

[0464] In addition, as shown in FIG. 19, when phase shifting units 209A and 209B perform phase shifting on data symbol 402 and data symbol 502, the effect of a sudden drop in field strength on the frequency axis in multipath can be reduced, which may result in an improvement in the reception quality of data for data symbol 402 and data symbol 502.

[0465] In this way, the difference between "symbols to be subjected to phase modification by phase modification section 205B" and "symbols to be subjected to phase modification by phase modification sections 209A and 209B" is a distinctive feature.

[0466] As described above, by performing a phase change using phase change unit 205B in FIG. 19, it is possible to obtain the effect of improving the reception quality of data at the receiving device for data symbol 402 and data symbol 502, for example, in an LOS environment, and by performing a phase change using phase change units 209A and 209B in FIG. 19, it is possible to obtain the effect of improving the reception quality at the receiving device for control information symbols included in, for example, "the frames of FIGS. 4 and 5" or "the frames of FIGS. 13 and 14", and simplifying the operations of demodulating and decoding data symbol 402 and data symbol 502.

[0467] In addition, by performing a phase change using phase change unit 205B in Figure 19, it is possible to obtain the effect of improving the reception quality of data at the receiving device for data symbol 402 and data symbol 502, for example, in an LOS environment, and further, by performing a phase change on data symbol 402 and data symbol 502 using phase change units 209A and 209B in Figure 19, the reception quality of data symbol 402 and data symbol 502 is improved.

[0468] It should be noted that Q in equation (38) may be an integer equal to or less than −2, and in this case, the period of phase change is the absolute value of Q. This point can also be applied to the first embodiment.

[0469] In addition, R in equation (49) may be an integer equal to or less than −2, and in this case, the period of phase change is the absolute value of R.

[0470] Furthermore, taking into consideration the contents explained in Supplementary Note 1, it is advisable to set the amount of cyclic delay set in phase changer 209A and the amount of cyclic delay set in phase changer 209B to different values.

[0471] (Fourth embodiment) In this embodiment, a method of implementing a configuration different from that shown in FIG. 2 in the first embodiment will be described.

[0472] FIG. 1 shows an example of the configuration of a transmitting device such as a base station, an access point, or a broadcasting station in this embodiment, and details have been explained in the first embodiment, so explanation will be omitted.

[0473] Signal processing unit 106 receives mapped signals 105_1 and 105_2, signal group 110, and control signal 100 as input, performs signal processing based on control signal 100, and outputs processed signals 106_A and 106_B. Here, processed signal 106_A is represented as u1(i), and processed signal 106_B is represented as u2(i). i is a symbol number, and is an integer equal to or greater than 0, for example. Details of the signal processing will be described with reference to FIG. 20.

[0474] Fig. 20 shows an example of the configuration of signal processing unit 106 in Fig. 1. Weighting combination unit (precoding unit) 203 receives mapped signal 201A (mapped signal 105_1 in Fig. 1), mapped signal 201B (mapped signal 105_2 in Fig. 1), and control signal 200 (control signal 100 in Fig. 1), performs weighting combination (precoding) based on control signal 200, and outputs weighted signal 204A and weighted signal 204B.

[0475] In this case, mapped signal 201A is represented as s1(t), mapped signal 201B as s2(t), weighted signal 204A as z1'(t), and weighted signal 204B as z2'(t). Note that t is, for example, time. s1(t), s2(t), z1'(t), and z2'(t) are defined as complex numbers, and therefore may also be real numbers.

[0476] Here, it is treated as a function of time, but it may be a function of "frequency (carrier number)", or a function of "time and frequency". It may also be a function of "symbol number". This is also the same as in the first embodiment.

[0477] The weighting synthesis unit (precoding unit) 203 performs the following calculation.

[0478]

number

[0479] Phase shifter 205A receives weighted and combined signal 204A and control signal 200 as input, and performs a phase shift on weighted and combined signal 204A based on control signal 200, outputting phase-shifted signal 206A. Phase-shifted signal 206A is represented by z1(t), which is defined as a complex number and may be a real number.

[0480] The specific operation of the phase changer 205A will be described. For example, the phase changer 205A applies a phase change of w(i) to z1'(i). Therefore, it can be expressed as z1(i) = w(i) × z1'(i), where i is the symbol number and is an integer equal to or greater than 0.

[0481] For example, the phase change value is set as follows:

[0482]

number

[0483] M is an integer equal to or greater than 2, and M is the period of phase change. If M is set to an odd number equal to or greater than 3, there is a possibility that the data reception quality will improve. However, Equation (51) is merely an example, and is not limited to this. Therefore, the phase change value w(i)=e j×λ(i) It is expressed as:

[0484] Phase shifter 205B receives weighted and combined signal 204B and control signal 200 as input, and performs a phase shift on weighted and combined signal 204B based on control signal 200, outputting phase-shifted signal 206B. Phase-shifted signal 206B is represented by z2(t), which is defined as a complex number and may be a real number.

[0485] The specific operation of the phase changer 205B will be described. For example, the phase changer 205B applies a phase change of y(i) to z2'(i). Therefore, it can be expressed as z2(i) = y(i) × z2'(i), where i is the symbol number and is an integer equal to or greater than 0.

[0486] For example, the phase change value is set as shown in equation (2). N is an integer equal to or greater than 2, and N is the phase change period. N ≠ M is satisfied. If N is set to an odd number equal to or greater than 3, there is a possibility that the data reception quality will improve. However, equation (2) is merely an example, and is not limited to this. Therefore, the phase change value y(i)=e j×δ(i) It is expressed as:

[0487] In this case, z1(i) and z2(i) are expressed by the following equations.

[0488]

number

[0489] Note that δ(i) and λ(i) are real numbers. Then, z1(i) and z2(i) are transmitted from the transmitting device at the same time and at the same frequency (same frequency band). In equation (52), the phase change value is not limited to equations (2) and (52), and a method of periodically and regularly changing the phase is also possible.

[0490] As explained in the first embodiment, the (precoding) matrices in equations (50) and (52) can be equations (5) to (36), etc. However, the precoding matrices are not limited to these, and the same applies to the first embodiment.

[0491] Insertion section 207A receives weighted and combined signal 204A, pilot symbol signal pa(t) 251A, preamble signal 252, control information symbol signal 253, and control signal 200 as input, and outputs baseband signal 208A based on the frame configuration, based on the frame configuration information included in control signal 200. t indicates time.

[0492] Similarly, insertion unit 207B receives phase-shifted signal 206B, pilot symbol signal pb(t) 251B, preamble signal 252, control information symbol signal 253, and control signal 200 as input, and outputs baseband signal 208B based on the frame configuration, based on the frame configuration information included in control signal 200.

[0493] Phase changer 209B receives baseband signal 208B and control signal 200, changes the phase of baseband signal 208B based on control signal 200, and outputs phase-changed signal 210B. Baseband signal 208B is a function of symbol number i, expressed as x'(i). Then, phase-changed signal x(i) 210B is expressed as x(i)=e j×ε(i) It can be expressed as ×x'(i), where i is an integer greater than or equal to 0 and j is the imaginary unit.

[0494] As explained in the first embodiment and the like, the operation of phase changer 209B may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209B performs phase change on symbols present in the frequency axis direction. Phase changer 209B performs phase change on data symbols, pilot symbols, control information symbols, etc.

[0495] FIG. 3 shows an example of the configuration of the radio units 107_A and 107_B in FIG. 1, and as detailed explanation has been given in the first embodiment, the explanation will be omitted.

[0496] FIG. 4 shows the frame structure of the transmission signal 108_A in FIG. 1, and as detailed explanation has been given in the first embodiment, the explanation will be omitted.

[0497] FIG. 5 shows the frame structure of the transmission signal 108_B in FIG. 1, and as detailed explanation has been given in the first embodiment, the explanation will be omitted.

[0498] When a symbol exists on carrier A, time $B in Figure 4 and a symbol exists on carrier A, time $B in Figure 5, the symbol on carrier A, time $B in Figure 4 and the symbol on carrier A, time $B in Figure 5 are transmitted at the same time and on the same frequency. Note that the frame structure is not limited to Figures 4 and 5, and Figures 4 and 5 are merely examples of frame structures.

[0499] The other symbols in Figures 4 and 5 are symbols corresponding to "preamble signal 252 and control information symbol signal 253 in Figure 2", and therefore, when other symbols 503 in Figure 5 at the same time and on the same frequency (same carrier) as other symbols 403 in Figure 4 transmit control information, they transmit the same data (same control information).

[0500] It is assumed that the receiving device receives the frame in Figure 4 and the frame in Figure 5 simultaneously, but the receiving device can obtain the data transmitted by the transmitting device even if it receives the frame in Figure 4 or the frame in Figure 5.

[0501] FIG. 6 shows an example of the configuration of a portion related to control information generation for generating control information signal 253 in FIG. 2, and as detailed explanation has been given in the first embodiment, explanation thereof will be omitted.

[0502] Fig. 7 shows an example of the configuration of antenna unit #A 109_A and antenna unit #B 109_B in Fig. 1, in which antenna unit #A 109_A and antenna unit #B 109_B are configured with multiple antennas. Fig. 7 has been explained in detail in the first embodiment, so its explanation will be omitted.

[0503] Figure 8 shows an example of the configuration of a receiving device that receives a modulated signal when the transmitting device of Figure 1 transmits a transmission signal having the frame structure of Figures 4 and 5, for example. Since a detailed explanation has been given in embodiment 1, a detailed explanation will be omitted here.

[0504] Fig. 10 shows an example of the configuration of antenna unit #X 801X and antenna unit #Y 801Y in Fig. 8, where antenna unit #X 801X and antenna unit #Y 801Y are configured with multiple antennas. Fig. 10 has been explained in detail in embodiment 1, so its explanation will be omitted.

[0505] Next, as shown in Fig. 1, signal processing unit 106 of the transmitting device is inserted with phase change units 205A, 205B and phase change unit 209A as shown in Fig. 20. The features and effects of this will be described.

[0506] As explained using Figures 4 and 5, phase modification units 205A and 205B perform precoding (weighted combining) on ​​mapped signal s1(i) 201A obtained by mapping using a first sequence and mapped signal s2(i) 201B obtained by mapping using a second sequence, and then perform phase modification on the resulting weighted combined signals 204A and 204B. Phase-modified signal 206A and phase-modified signal 206B are transmitted at the same frequency and at the same time. Therefore, in Figures 4 and 5, phase modification is performed on data symbol 402 in Figure 4 and data symbol 502 in Figure 5. i is a symbol number, and is an integer equal to or greater than 0.

[0507] For example, Fig. 11 shows carrier 1 to carrier 5 and time $4 to time $6 extracted from the frame in Fig. 4. Note that Fig. 11 shows pilot symbols 401, data symbols 402, and other symbols 403, just like Fig. 4.

[0508] As described above, in the symbols shown in FIG. 11, phase modification unit 205A applies phase modification to the data symbols at (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6).

[0509] Therefore, the phase change value for the data symbol shown in FIG. 11 is (Carrier 1, Time $5) j×λ15(i) "year, (Carrier 2, Time $5) j×λ25(i) "year, (Carrier 3, Time $5) j×λ35(i) "year, (Carrier 4, Time $5) j×λ45(i) "year, (Carrier 5, Time $5) j×λ55(i) "year, (Carrier 1, Time $6) j×λ16(i) "year, (Carrier 2, time $6) j×λ26(i) "year, (Carrier 4, Time $6) j×λ46(i) "year, (Carrier 5, Time $6) j×λ56(i) "

[0510] On the other hand, in the symbols shown in Figure 11, other symbols in (carrier 1, time $4), (carrier 2, time $4), (carrier 3, time $4), (carrier 4, time $4), and (carrier 5, time $4), and the pilot symbol in (carrier 3, time $6) are not subject to phase modification by phase modification unit 205A.

[0511] This is a characteristic feature of phase changer 205A. Note that, as shown in Fig. 4, data carriers are allocated at the "same carrier, same time" as the data symbols in (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6), which are the targets of phase change in Fig. 11.

[0512] That is, in Figure 4, (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6) are data symbols.

[0513] That is, data symbols that are subjected to MIMO transmission or that transmit a plurality of streams are the targets of phase modification by phase modification section 205A.

[0514] An example of the phase change that the phase change unit 205A applies to the data symbols is a method of performing regular phase change on the data symbols, that is, a phase change with a period of N, as shown in equation (50). However, the method of changing the phase of the data symbols is not limited to this.

[0515] For example, Fig. 11 shows carrier 1 to carrier 5 and time $4 to time $6 extracted from the frame in Fig. 5. Note that Fig. 11 shows pilot symbols 501, data symbols 502, and other symbols 503, just like Fig. 5.

[0516] As described above, in the symbols shown in FIG. 11, phase change unit 205B applies phase change to the data symbols at (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6).

[0517] Therefore, the phase change value for the data symbol shown in FIG. 11 is "e j×δ15(i) " and (carrier 2, time $5) "e j×δ25(i) " and (carrier 3, time $5) is "e j×δ35(i) " and (carrier 4, time $5) is "e j×δ45(i) " and (carrier 5, time $5) is "e j×δ55(i) " and (Carrier 1, Time $6) is "e j×δ16(i) " and (carrier 2, time $6) is "e j×δ26(i) " and (carrier 4, time $6) is "e j×δ46(i) " and (carrier 5, time $6) is "e j×δ56(i) "

[0518] On the other hand, in the symbols shown in Figure 11, other symbols in (carrier 1, time $4), (carrier 2, time $4), (carrier 3, time $4), (carrier 4, time $4), and carrier 5, time $4), and the pilot symbol in (carrier 3, time $6) are not subject to phase modification by phase modification unit 205B.

[0519] This is a characteristic feature of phase changer 205B. Note that, as shown in Fig. 4, data carriers are allocated at the "same carrier, same time" as the data symbols in (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6), which are the targets of phase change in Fig. 11.

[0520] That is, in Figure 4, (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6) are data symbols.

[0521] That is, data symbols that are subjected to MIMO transmission or transmission of multiple streams are the targets of phase modification by phase modification section 205B.

[0522] An example of the phase change that the phase change unit 205B applies to the data symbols is a method of performing regular phase change on the data symbols, that is, a phase change with a period of N, as shown in equation (2). However, the method of changing the phase of the data symbols is not limited to this.

[0523] By doing so, in an environment where direct waves are dominant, for example, in an LOS environment, it is possible to obtain an effect of improving the reception quality of data in a receiving device for data symbols that are transmitting MIMO transmission or multiple streams. This effect will be explained below.

[0524] For example, the modulation scheme used in mapping section 104 in Fig. 1 is QPSK. Mapped signal 201A in Fig. 18 is a QPSK signal, and mapped signal 201B is also a QPSK signal. In other words, two QPSK streams are transmitted.

[0525] Then, in the signal processing unit 811 in FIG. 8, for example, 16 candidate signal points are obtained using the channel estimation signals 806_1 and 806_2. QPSK can transmit 2 bits, and a total of 4 bits are transmitted by two streams. 4 = 16 candidate signal points.

[0526] It should be noted that another 16 candidate signal points can be obtained using channel estimation signals 808_1 and 808_2, but the explanation would be similar, so we will focus on the 16 candidate signal points obtained using channel estimation signals 806_1 and 806_2 and proceed with the explanation.

[0527] An example of this state is shown in Figure 12. In both Figures 12A and 12B, the horizontal axis is in-phase I and the vertical axis is quadrature Q, and there are 16 candidate signal points on the in-phase I-quadrature Q plane. One of the 16 candidate signal points is the signal point transmitted by the transmitting device. For this reason, they are called "16 candidate signal points."

[0528] In an environment where direct waves are dominant, for example, an LOS environment, the first case is considered as "a case where phase change units 205A and 205B of FIG. 20 do not exist, that is, a case where phase change is not performed by phase change units 205A and 205B of FIG. 20."

[0529] In the "first case," no phase change is performed, which may result in the state shown in Fig. 12A. When the state shown in Fig. 12A occurs, there are areas where signal points are densely packed, such as "signal points 1201 and 1202," "signal points 1203, 1204, 1205 and 1206," and "signal points 1207 and 1208," which may result in a decrease in data reception quality in the receiving device of Fig. 8.

[0530] To overcome this phenomenon, phase shifters 205A and 205B are inserted in Fig. 20. When phase shifters 205A and 205B are inserted, symbol number i will contain a mixture of symbol numbers where "areas where signal points are densely packed" as shown in Fig. 12A and symbol numbers where "the distance between signal points is long" as shown in Fig. 12B. To address this situation, error correction coding is introduced, making it possible to obtain high error correction capabilities and high data reception quality in the receiving device of Fig. 8.

[0531] 20, phase change sections 205A and 205B in Fig. 20 do not change the phase of "pilot symbols and preambles" used for channel estimation to demodulate (detect) data symbols, such as pilot symbols and preambles. This makes it possible to achieve, in data symbols, "a mixture of symbol numbers where "areas where signal points are densely packed" as shown in Fig. 12A and symbol numbers where "the distance between signal points is long" as shown in Fig. 12B, depending on symbol number i."

[0532] However, even if phase change units 205A and 205B in FIG. 20 change the phase of "pilot symbols and preambles" used for channel estimation to demodulate (detect) data symbols, there are cases where "in data symbols, it is possible to achieve a mixture of symbol numbers where there are dense signal points as shown in FIG. 12A and symbol numbers where the distance between signal points is long as shown in FIG. 12B, depending on symbol number i."

[0533] In this case, some conditions must be imposed on the phase change of the pilot symbols and preambles. For example, a method can be considered in which a different rule is established from the rule for phase change of the data symbols, and "phase change is applied to the pilot symbols and / or preambles." For example, there is a method in which phase change is applied to the data symbols regularly with a period of N, and phase change is applied to the pilot symbols and / or preambles regularly with a period of M. N and M are integers equal to or greater than 2.

[0534] As described above, phase changer 209B receives baseband signal 208B and control signal 200 as input, changes the phase of baseband signal 208B based on control signal 200, and outputs phase-changed signal 210B. Baseband signal 208B is a function of symbol number i, expressed as x'(i). Then, phase-changed signal 210B(x(i)) is expressed as x(i)=e j×ε(i)It can be expressed as ×x'(i), where i is an integer greater than or equal to 0 and j is the imaginary unit.

[0535] The operation of phase changer 209B may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209B performs phase change on symbols present in the frequency axis direction. Phase changer 209B performs phase change on data symbols, pilot symbols, control information symbols, etc. Therefore, in this case, the symbols targeted by symbol number i are data symbols, pilot symbols, control information symbols, preambles (other symbols), etc.

[0536] In the case of FIG. 20, phase change section 209B applies a phase change to baseband signal 208B, and therefore applies a phase change to each symbol shown in FIG.

[0537] Therefore, in the frame of FIG. 5, phase change section 209B of FIG. 20 applies phase change to all symbols (other symbols 503) of all carriers at time $1.

[0538] Similarly, phase change section 209B in FIG. 20 performs phase change on the following symbols: "All symbols of all carriers at time $2 (other symbols 503)" "All symbols of all carriers at time $3 (other symbols 503)" "All symbols of all carriers at time $4 (other symbols 503)" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $5" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $6" "All symbols of all carriers at time $7 (pilot symbol 501 or data symbol 502)" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $8" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $9" "All symbols of all carriers at time $10 (pilot symbol 501 or data symbol 502)" "All symbols (pilot symbol 501 or data symbol 502) of all carriers at time $11"; times and carriers other than those mentioned above are omitted.

[0539] FIG. 13 shows a frame configuration different from that of FIG. 4 of the transmission signal 108_A in FIG. 1, and as detailed explanation has been given in the first embodiment, explanation will be omitted.

[0540] FIG. 14 shows a frame configuration different from that of FIG. 5 of the transmission signal 108_B in FIG. 1, and as detailed explanation has been given in the first embodiment, explanation will be omitted.

[0541] When a symbol exists on carrier A, time $B in Figure 13 and a symbol exists on carrier A, time $B in Figure 14, the symbol on carrier A, time $B in Figure 13 and the symbol on carrier A, time $B in Figure 14 are transmitted at the same time and on the same frequency. Note that the frame structures in Figures 13 and 14 are merely examples.

[0542] The other symbols in Figures 13 and 14 are symbols equivalent to "preamble signal 252 and control information symbol signal 253 in Figure 20", and therefore, when other symbols 503 in Figure 14 at the same time and on the same frequency (same carrier) as other symbols 403 in Figure 13 transmit control information, they transmit the same data (same control information).

[0543] It is assumed that the receiving device receives the frame in Figure 13 and the frame in Figure 14 simultaneously, but the receiving device can obtain the data transmitted by the transmitting device even if it receives the frame in Figure 13 or the frame in Figure 14.

[0544] Phase changer 209B receives baseband signal 208B and control signal 200 as input, changes the phase of baseband signal 208B based on control signal 200, and outputs phase-changed signal 210B. Baseband signal 208B is represented as a function of symbol number i, as x'(i).

[0545] Then, the phase-shifted signal 210B(x(i)) is expressed as x(i)=e j×ε(i) ×x'(i), where i is an integer equal to or greater than 0, and j is an imaginary unit. The operation of phase changer 209B may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3.

[0546] The phase change unit 209B performs a phase change on symbols present in the frequency axis direction. The phase change unit 209B performs a phase change on data symbols, pilot symbols, control information symbols, etc. At this time, null symbols can also be considered to be targets for phase change. Therefore, in this case, the symbols targeted by symbol number i are data symbols, pilot symbols, control information symbols, preambles (other symbols), null symbols, etc.

[0547] However, since the null symbol has an in-phase component I of zero (0) and an orthogonal component Q of zero (0), even if a phase change is performed on the null symbol, the signal before and after the phase change is the same. Therefore, it is also possible to interpret the null symbol as not being subject to phase change. In the case of Figure 20, phase change unit 209B performs a phase change on baseband signal 208B, and therefore performs a phase change on each symbol shown in Figure 14.

[0548] Therefore, in the frame of Fig. 14, phase change unit 209B of Fig. 20 applies phase change to all symbols (other symbols 503) of all carriers at time $1. However, the handling of phase change for null symbol 1301 is as explained above.

[0549] Similarly, the phase change unit 209B in FIG. 20 performs phase change on the following symbols: "All symbols of all carriers at time $2 (other symbols 503)" "All symbols of all carriers at time $3 (other symbols 503)" "All symbols of all carriers at time $4 (other symbols 503)" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $5" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $6" "All symbols of all carriers at time $7 (pilot symbol 501 or data symbol 502)" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $8" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $9" "All symbols of all carriers at time $10 (pilot symbol 501 or data symbol 502)" "For all symbols of all carriers at time $11 (pilot symbol 501 or data symbol 502)", however, the handling of the phase change of the null symbol 1301 at all times and all carriers is as explained above. Descriptions of times and carriers other than those mentioned above are omitted.

[0550] The phase change value in phase changer 209B is represented as Ω(i). Baseband signal 208B is x'(i), and phase-changed signal 210B is x(i). Therefore, x(i) = Ω(i) × x'(i) holds.

[0551] For example, the phase change value is set as shown in equation (38). Q is an integer equal to or greater than 2, and Q is the period of the phase change. j is an imaginary unit. However, equation (38) is merely an example and is not limited to this.

[0552] For example, Ω(i) may be set to perform a phase change with a period Q.

[0553] 5 and 14, the same phase change value may be given to the same carrier, and the phase change value may be set for each carrier. For carrier 1 in Figures 5 and 14, the phase change value is set to equation (39) regardless of time. For carrier 2 in Figures 5 and 14, the phase change value is set to equation (40) regardless of time. For carrier 3 in Figures 5 and 14, the phase change value is set to equation (41) regardless of time. 5 and 14, the phase change value is set to Equation (42) regardless of time. The description of subsequent carriers is omitted.

[0554] The above is an example of the operation of the phase changer 209B in FIG.

[0555] The effect obtained by the phase changer 209B in FIG. 20 will be described.

[0556] Other symbols 403, 503 in the "frames of Figs. 4 and 5" or "frames of Figs. 13 and 14" contain control information symbols. As described above, other symbol 503 in Fig. 5, which transmits control information at the same time and on the same frequency (same carrier) as other symbol 403, transmits the same data (same control information).

[0557] Now, consider Case 2: "The control information symbol is transmitted using either the antenna unit #A 109_A or the antenna unit #B 109_B in FIG. 1."

[0558] When transmitting as in "Case 2," the number of antennas that transmit control information symbols is one, and therefore the spatial diversity gain is smaller than when "control information symbols are transmitted using both antenna unit #A 109_A and antenna unit #B 109_B," and therefore, in "Case 2," the reception quality of data is reduced even when received by the receiving device of Fig. 8. Therefore, in terms of improving the reception quality of data, it is better to "transmit control information symbols using both antenna unit #A 109_A and antenna unit #B 109_B."

[0559] Case 3: Consider the case where "control information symbols are transmitted using both antenna unit #A 109_A and antenna unit #B 109_B in FIG. 1, but phase change is not performed in phase change unit 209B in FIG. 20."

[0560] When transmitting as in "Case 3," the modulated signal transmitted from antenna unit #A 109_A and the modulated signal transmitted from antenna unit #B 109_B are the same or have a specific phase shift, so depending on the radio wave propagation environment, the receiving device in Figure 8 may receive a poor signal, and both modulated signals may be affected by the same multipath. This can cause a phenomenon in which the data reception quality in the receiving device in Figure 8 deteriorates.

[0561] To mitigate this phenomenon, phase change unit 209B is provided in Fig. 20. This changes the phase in the time or frequency direction, thereby reducing the possibility of a poorly received signal in the receiving device of Fig. 8. Furthermore, since there is a high possibility that the influence of multipath on the modulated signal transmitted from antenna unit #A 109_A is different from the influence of multipath on the modulated signal transmitted from antenna unit #B 109_B, there is a high possibility that diversity gain can be obtained, thereby improving the data reception quality in the receiving device of Fig. 8.

[0562] For the above reasons, in FIG. 20, a phase change section 209B is provided to change the phase.

[0563] In addition to the control information symbols, other symbols 403 and other symbols 503 include, for example, symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation, in order to demodulate and decode the control information symbols. Also, the "frames of Figures 4 and 5" or the "frames of Figures 13 and 14" include pilot symbols 401 and 501, and by using these, it is possible to demodulate and decode the control information symbols with higher accuracy.

[0564] In the "frames of Figures 4 and 5" or the "frames of Figures 13 and 14", multiple streams are transmitted using the same frequency (frequency band) and the same time using data symbol 402 and data symbol 502, or MIMO transmission is performed.

[0565] To demodulate these data symbols, symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation included in other symbols 403 and other symbols 503 are used.

[0566] At this time, the phases of "the symbols for signal detection, the symbols for frequency synchronization and time synchronization, and the symbols for channel estimation included in other symbols 403 and other symbols 503" are changed by phase change unit 209B as described above.

[0567] In such a situation, if this processing is not reflected "on data symbol 402 and data symbol 502" or "in the case of the above explanation, on data symbol 502," when demodulating and decoding data symbol 402 and data symbol 502 in the receiving device, demodulation and decoding must be performed that reflects the processing for the phase change performed in phase change unit 209B, and this processing is likely to become complicated.

[0568] This is because the phases of "symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation included in other symbols 403 and other symbols 503" have been changed by phase change unit 209B.

[0569] However, as shown in FIG. 20, when phase change section 209B performs a phase change on "data symbol 402 and data symbol 502," or "in the case of the above description, on data symbol 502," there is an advantage that the receiving device can easily demodulate and decode data symbol 402 and data symbol 502 using a channel estimation signal (a propagation path fluctuation estimation signal) estimated using "other symbols 403 and, which are included in other symbols 503, symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation."

[0570] In addition, as shown in FIG. 20, when phase change unit 209B performs a phase change on "data symbol 402 and data symbol 502," or "in the case of the above description, on data symbol 502," it is possible to reduce the effect of a sudden drop in field strength on the frequency axis in multipath, which may result in an improvement in the reception quality of data for data symbol 402 and data symbol 502.

[0571] In this way, the characteristic feature is that "the target symbols for which phase change is performed by phase change sections 205A and 205B" and "the target symbols for which phase change is performed by phase change section 209B" are different.

[0572] As described above, by performing a phase change using phase change units 205A and 205B in FIG. 20, it is possible to obtain the effect of improving the reception quality of data at the receiving device for data symbol 402 and data symbol 502, for example, in an LOS environment, and by performing a phase change using phase change unit 209B in FIG. 20, it is possible to obtain the effect of improving the reception quality at the receiving device for control information symbols included in, for example, "the frames of FIGS. 4 and 5" or "the frames of FIGS. 13 and 14", and simplifying the operations of demodulating and decoding data symbol 402 and data symbol 502.

[0573] In addition, by performing phase change using phase change units 205A and 205B in Figure 20, it is possible to obtain the effect of improving the reception quality of data at the receiving device for data symbol 402 and data symbol 502, for example in an LOS environment, and further, by performing phase change on data symbol 402 and data symbol 502 using phase change unit 209B in Figure 20, the reception quality of data symbol 402 and data symbol 502 is improved.

[0574] It should be noted that Q in equation (38) may be an integer equal to or less than −2, and in this case, the period of phase change is the absolute value of Q. This point can also be applied to the first embodiment.

[0575] (Embodiment 5) In this embodiment, a method of implementing a configuration different from that shown in FIG. 2 in the first embodiment will be described.

[0576] FIG. 1 shows an example of the configuration of a transmitting device such as a base station, an access point, or a broadcasting station in this embodiment, and details have been explained in the first embodiment, so explanation will be omitted.

[0577] Signal processing unit 106 receives mapped signals 105_1 and 105_2, signal group 110, and control signal 100 as input, performs signal processing based on control signal 100, and outputs processed signals 106_A and 106_B. Here, processed signal 106_A is represented as u1(i), and processed signal 106_B is represented as u2(i). i is a symbol number, and is an integer equal to or greater than 0, for example. Details of the signal processing will be described with reference to FIG. 21.

[0578] Fig. 21 shows an example of the configuration of signal processing unit 106 in Fig. 1. Weighting combination unit (precoding unit) 203 receives mapped signal 201A (mapped signal 105_1 in Fig. 1), mapped signal 201B (mapped signal 105_2 in Fig. 1), and control signal 200 (control signal 100 in Fig. 1), performs weighting combination (precoding) based on control signal 200, and outputs weighted signal 204A and weighted signal 204B.

[0579] In this case, mapped signal 201A is represented as s1(t), mapped signal 201B as s2(t), weighted signal 204A as z1'(t), and weighted signal 204B as z2'(t). Note that t is, for example, time. s1(t), s2(t), z1'(t), and z2'(t) are defined as complex numbers, and therefore may also be real numbers.

[0580] Here, it is treated as a function of time, but it may be a function of "frequency (carrier number)", or a function of "time and frequency". It may also be a function of "symbol number". This is also the same as in the first embodiment.

[0581] The weighting and combining unit (precoding unit) 203 performs the calculation of equation (49).

[0582] Phase shifter 205A receives weighted and combined signal 204A and control signal 200 as input, performs a phase shift on weighted and combined signal 204A based on control signal 200, and outputs phase-shifted signal 206A. Phase-shifted signal 206A is represented by z1(t), which is defined as a complex number and may also be a real number.

[0583] The specific operation of the phase changer 205A will be described. For example, the phase changer 205A applies a phase change of w(i) to z1'(i). Therefore, it can be expressed as z1(i) = w(i) × z1'(i), where i is the symbol number and is an integer equal to or greater than 0.

[0584] For example, the phase change value is set as shown in equation (50).

[0585] M is an integer equal to or greater than 2, and M is the period of phase change. Also, if M is set to an odd number equal to or greater than 3, there is a possibility that the data reception quality will improve. However, Equation (50) is merely an example, and is not limited to this. Therefore, the phase change value w(i)=e j×λ(i) It is expressed as:

[0586] Phase shifter 205B receives weighted and combined signal 204B and control signal 200 as input, and performs a phase shift on weighted and combined signal 204B based on control signal 200, outputting phase-shifted signal 206B. Phase-shifted signal 206B is represented by z2(t), which is defined as a complex number and may also be a real number.

[0587] The specific operation of the phase changer 205B will be described. For example, the phase changer 205B applies a phase change of y(i) to z2'(i). Therefore, it can be expressed as z2(i) = y(i) × z2'(i), where i is the symbol number and is an integer equal to or greater than 0.

[0588] For example, the phase change value is set as shown in equation (2). N is an integer equal to or greater than 2, and N is the phase change period. N ≠ M is satisfied. If N is set to an odd number equal to or greater than 3, there is a possibility that the data reception quality will improve. However, equation (2) is merely an example, and is not limited to this. Therefore, the phase change value y(i)=e j×δ(i) It is expressed as:

[0589] In this case, z1(i) and z2(i) can be expressed by equation (51).

[0590] Note that δ(i) and λ(i) are real numbers. Then, z1(i) and z2(i) are transmitted from the transmitting device at the same time and at the same frequency (same frequency band). In equation (51), the phase change value is not limited to equations (2) and (51), and a method of periodically and regularly changing the phase is also possible.

[0591] As explained in the first embodiment, the matrices (precoding matrices) in equations (49) and (51) can be equations (5) to (36), etc. However, the precoding matrices are not limited to these, and the same applies to the first embodiment.

[0592] Insertion section 207A receives weighted and combined signal 204A, pilot symbol signal pa(t) 251A, preamble signal 252, control information symbol signal 253, and control signal 200 as input, and outputs baseband signal 208A based on the frame configuration, based on information about the frame configuration included in control signal 200. t indicates time.

[0593] Similarly, insertion unit 207B receives phase-shifted signal 206B, pilot symbol signal pb(t) 251B, preamble signal 252, control information symbol signal 253, and control signal 200 as input, and outputs baseband signal 208B based on the frame configuration, based on the frame configuration information included in control signal 200.

[0594] Phase changer 209B receives baseband signal 208B and control signal 200, changes the phase of baseband signal 208B based on control signal 200, and outputs phase-changed signal 210B. Baseband signal 208B is a function of symbol number i, expressed as x'(i). Then, phase-changed signal x(i) 210B is expressed as x(i)=e j×ε(i) It can be expressed as ×x'(i), where i is an integer greater than or equal to 0 and j is the imaginary unit.

[0595] As explained in the first embodiment and the like, the operation of phase changer 209B may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209B performs phase change on symbols present in the frequency axis direction. Phase changer 209B performs phase change on data symbols, pilot symbols, control information symbols, etc.

[0596] FIG. 3 shows an example of the configuration of radio units 107_A and 107_B in FIG. 1, FIG. 4 shows the frame configuration of transmission signal 108_A in FIG. 1, and FIG. 5 shows the frame configuration of transmission signal 108_B in FIG. 1. Since detailed explanations have been given in embodiment 1, explanations will be omitted.

[0597] When a symbol exists on carrier A, time $B in Figure 4 and a symbol exists on carrier A, time $B in Figure 5, the symbol on carrier A, time $B in Figure 4 and the symbol on carrier A, time $B in Figure 5 are transmitted at the same time and on the same frequency. Note that the frame structure is not limited to Figures 4 and 5, and Figures 4 and 5 are merely examples of frame structures.

[0598] The other symbols in Figures 4 and 5 are symbols corresponding to "preamble signal 252 and control information symbol signal 253 in Figure 2", and therefore, when other symbols 503 in Figure 5 at the same time and on the same frequency (same carrier) as other symbols 403 in Figure 4 transmit control information, they transmit the same data (same control information).

[0599] It is assumed that the receiving device receives the frame in Figure 4 and the frame in Figure 5 simultaneously, but the receiving device can obtain the data transmitted by the transmitting device even if it receives the frame in Figure 4 or the frame in Figure 5.

[0600] FIG. 6 shows an example of the configuration of a portion related to control information generation for generating control information signal 253 in FIG. 2, and as detailed explanation has been given in the first embodiment, explanation thereof will be omitted.

[0601] Fig. 7 shows an example of the configuration of antenna unit #A 109_A and antenna unit #B 109_B in Fig. 1, in which antenna unit #A 109_A and antenna unit #B 109_B are configured with multiple antennas. Fig. 7 has been explained in detail in the first embodiment, so its explanation will be omitted.

[0602] Figure 8 shows an example of the configuration of a receiving device that receives a modulated signal when the transmitting device of Figure 1 transmits a transmission signal having the frame structure of Figures 4 and 5, for example. Since a detailed explanation has been given in embodiment 1, a detailed explanation will be omitted here.

[0603] Fig. 10 shows an example of the configuration of antenna unit #X 801X and antenna unit #Y 801Y in Fig. 8, where antenna unit #X 801X and antenna unit #Y 801Y are configured with multiple antennas. Fig. 10 has been explained in detail in embodiment 1, so its explanation will be omitted.

[0604] Next, as shown in Fig. 1, signal processing unit 106 of the transmitting device is inserted with phase change units 205A, 205B and phase change unit 209B as shown in Fig. 21. The features and effects of this will be described.

[0605] As explained using Figures 4 and 5, phase change sections 205A and 205B perform precoding (weighting and combining) on ​​mapped signal s1(i) 201A obtained by mapping using a first sequence and mapped signal s2(i) (201B) obtained by mapping using a second sequence, and then perform phase change on the resulting weighted and combined signals 204A and 204B, where i is a symbol number and is an integer equal to or greater than 0.

[0606] Then, phase-changed signal 206A and phase-changed signal 206B are transmitted at the same frequency and at the same time. Therefore, in Figures 4 and 5, phase change is applied to data symbol 402 in Figure 4 and data symbol 502 in Figure 5.

[0607] For example, Fig. 11 shows carrier 1 to carrier 5 and time $4 to time $6 extracted from the frame in Fig. 4. Note that Fig. 11 shows pilot symbols 401, data symbols 402, and other symbols 403, just like Fig. 4.

[0608] As described above, in the symbols shown in FIG. 11, phase modification unit 205A applies phase modification to the data symbols at (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6).

[0609] Therefore, the phase change value for the data symbol shown in FIG. 11 is "e j×λ15(i) " and (carrier 2, time $5) "e j×λ25(i) " and (carrier 3, time $5) is "ej×λ35(i) " and (carrier 4, time $5) is "e j×λ45(i) " and (carrier 5, time $5) is "e j×λ55(i) " and (Carrier 1, Time $6) is "e j×λ16(i) " and (carrier 2, time $6) is "e j×λ26(i) " and (carrier 4, time $6) is "e j×λ46(i) " and (carrier 5, time $6) is "e j×λ56(i) "

[0610] On the other hand, in the symbols shown in Figure 11, other symbols in (carrier 1, time $4), (carrier 2, time $4), (carrier 3, time $4), (carrier 4, time $4), and (carrier 5, time $4), and the pilot symbol in (carrier 3, time $6) are not subject to phase modification by phase modification unit 205A.

[0611] This is a characteristic feature of phase changer 205A. Note that, as shown in Fig. 4, data carriers are allocated at the "same carrier, same time" as the data symbols in (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6), which are the targets of phase change in Fig. 11.

[0612] That is, in Figure 4, (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6) are data symbols.

[0613] That is, data symbols that are subjected to MIMO transmission or that transmit a plurality of streams are the targets of phase modification by phase modification section 205A.

[0614] An example of the phase change that the phase change unit 205A applies to the data symbols is a method of performing a regular phase change on the data symbols, that is, a phase change with a period of N, as shown in equation (50). However, the method of changing the phase of the data symbols is not limited to this.

[0615] For example, Fig. 11 shows carrier 1 to carrier 5 and time $4 to time $6 extracted from the frame in Fig. 5. Note that Fig. 11 shows pilot symbols 501, data symbols 502, and other symbols 503, just like Fig. 5.

[0616] As described above, in the symbols shown in FIG. 11, phase change unit 205B applies phase change to the data symbols at (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6).

[0617] Therefore, the phase change value for the data symbol shown in FIG. 11 is "e j×δ15(i) " and (carrier 2, time $5) "e j×δ25(i) " and (carrier 3, time $5) is "e j×δ35(i) " and (carrier 4, time $5) is "e j×δ45(i) " and (carrier 5, time $5) is "e j×δ55(i) " and (Carrier 1, Time $6) is "e j×δ16(i) " and (carrier 2, time $6) is "e j×δ26(i) " and (carrier 4, time $6) is "e j×δ46(i) " and (carrier 5, time $6) is "e j×δ56(i) "

[0618] On the other hand, in the symbols shown in Figure 11, other symbols in (carrier 1, time $4), (carrier 2, time $4), (carrier 3, time $4), (carrier 4, time $4), and (carrier 5, time $4), and the pilot symbol in (carrier 3, time $6) are not subject to phase modification by phase modification unit 205B.

[0619] In addition, as shown in Figure 4, data carriers are arranged at the "same carrier, same time" as the data symbols in (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6), which are the targets of phase change in Figure 11.

[0620] That is, in Figure 4, (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6) are data symbols.

[0621] That is, data symbols that are subjected to MIMO transmission or transmission of multiple streams are the targets of phase modification by phase modification section 205B.

[0622] An example of the phase change that the phase change unit 205B applies to the data symbols is a method of performing regular phase change on the data symbols, that is, a phase change with a period of N, as shown in equation (2). However, the method of changing the phase of the data symbols is not limited to this.

[0623] By doing so, in an environment where direct waves are dominant, such as an LOS environment, it is possible to obtain an effect of improving the reception quality of data at a receiving device for data symbols that are transmitting MIMO transmission or multiple streams. This effect will now be explained.

[0624] For example, the modulation scheme used in mapping section 104 in Fig. 1 is QPSK. Mapped signal 201A in Fig. 18 is a QPSK signal, and mapped signal 201B is also a QPSK signal. In other words, two QPSK streams are transmitted.

[0625] Then, in the signal processing unit 811 in FIG. 8, for example, 16 candidate signal points are obtained using the channel estimation signals 806_1 and 806_2. QPSK can transmit 2 bits, and a total of 4 bits are transmitted by two streams. 4 = 16 candidate signal points.

[0626] It should be noted that another 16 candidate signal points can be obtained using channel estimation signals 808_1 and 808_2, but the explanation would be similar, so we will focus on the 16 candidate signal points obtained using channel estimation signals 806_1 and 806_2 and proceed with the explanation.

[0627] An example of this state is shown in Figure 12. In both Figures 12A and 12B, the horizontal axis is in-phase I and the vertical axis is quadrature Q, and there are 16 candidate signal points on the in-phase I-quadrature Q plane. One of the 16 candidate signal points is the signal point transmitted by the transmitting device. For this reason, they are called "16 candidate signal points."

[0628] In an environment where direct waves are dominant, for example, an LOS environment, the first case is considered as "a case where phase shifters 205A and 205B of FIG. 21 do not exist, that is, a case where phase shifters 205A and 205B of FIG. 21 do not perform phase shifting."

[0629] In the "first case," no phase change is performed, which may result in the state shown in Fig. 12A. When the state shown in Fig. 12A occurs, there are areas where signal points are densely packed, such as "signal points 1201 and 1202," "signal points 1203, 1204, 1205 and 1206," and "signal points 1207 and 1208," which may result in a decrease in data reception quality in the receiving device of Fig. 8.

[0630] To overcome this phenomenon, phase shifters 205A and 205B are inserted in Fig. 21. When phase shifters 205A and 205B are inserted, symbol number i will contain a mixture of symbol numbers where "areas where signal points are densely packed" as shown in Fig. 12A and symbol numbers where "the distance between signal points is long" as shown in Fig. 12B. To address this situation, error correction coding is introduced, making it possible to obtain high error correction capabilities and high data reception quality in the receiving device of Fig. 8.

[0631] 21, phase change sections 205A and 205B in Fig. 21 do not change the phase of "pilot symbols and preambles" used for channel estimation to demodulate (detect) data symbols, such as pilot symbols and preambles. This makes it possible to achieve, in data symbols, "a mixture of symbol numbers where "areas where signal points are densely packed" as shown in Fig. 12A and symbol numbers where "the distance between signal points is long" as shown in Fig. 12B, depending on symbol number i."

[0632] However, even if phase change units 205A and 205B in FIG. 21 change the phase of "pilot symbols and preambles" used for channel estimation to demodulate (detect) data symbols, there are cases where "in data symbols, it is possible to achieve a mixture of symbol numbers where there are dense signal points as shown in FIG. 12A and symbol numbers where the distance between signal points is long as shown in FIG. 12B, depending on symbol number i."

[0633] In this case, some conditions must be imposed on the phase change of the pilot symbols and preambles. For example, a method can be considered in which a different rule is established from the rule for phase change of the data symbols, and "phase change is applied to the pilot symbols and / or preambles." For example, there is a method in which phase change is applied to the data symbols regularly with a period of N, and phase change is applied to the pilot symbols and / or preambles regularly with a period of M. N and M are integers equal to or greater than 2.

[0634] As described above, phase changer 209A receives baseband signal 208A and control signal 200 as input, changes the phase of baseband signal 208A based on control signal 200, and outputs phase-changed signal 210A. Baseband signal 208A is a function of symbol number i, expressed as x'(i). Then, phase-changed signal 210A(x(i)) is expressed as x(i)=e j×ε(i) It can be expressed as ×x'(i), where i is an integer greater than or equal to 0 and j is the imaginary unit.

[0635] The operation of phase changer 209A may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209A performs phase change on symbols present in the frequency axis direction. Phase changer 209A performs phase change on data symbols, pilot symbols, control information symbols, etc. Therefore, in this case, the symbols targeted by symbol number i are data symbols, pilot symbols, control information symbols, preambles (other symbols), etc.

[0636] In FIG. 21, phase change section 209A applies a phase change to baseband signal 208A, and therefore applies a phase change to each symbol shown in FIG.

[0637] Therefore, in the frame of FIG. 4, phase change section 209A of FIG. 21 applies phase change to all symbols (other symbols 403) of all carriers at time $1.

[0638] Similarly, the phase change unit 209A in FIG. 21 performs phase change on the following symbols: "All symbols of all carriers at time $2 (other symbols 403)" "All symbols of all carriers at time $3 (other symbols 403)" "All symbols of all carriers at time $4 (other symbols 403)" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $5" "For all symbols of all carriers at time $6 (pilot symbol 401 or data symbol 402)" "For all symbols of all carriers at time $7 (pilot symbol 401 or data symbol 402)" "For all symbols of all carriers at time $8 (pilot symbol 401 or data symbol 402)" "For all symbols of all carriers at time $9 (pilot symbol 401 or data symbol 402)" "For all symbols of all carriers at time $10 (pilot symbol 401 or data symbol 402)" "For all symbols of all carriers at time $11 (pilot symbol 401 or data symbol 402)", and descriptions for times and carriers other than those mentioned above are omitted.

[0639] FIG. 13 shows a frame configuration different from that of FIG. 4 of the transmission signal 108_A in FIG. 1, and as detailed explanation has been given in the first embodiment, explanation will be omitted.

[0640] FIG. 14 shows a frame configuration different from that of FIG. 5 of the transmission signal 108_B in FIG. 1, and as detailed explanation has been given in the first embodiment, explanation will be omitted.

[0641] When a symbol exists on carrier A, time $B in Figure 13 and a symbol exists on carrier A, time $B in Figure 14, the symbol on carrier A, time $B in Figure 13 and the symbol on carrier A, time $B in Figure 14 are transmitted at the same time and on the same frequency. Note that the frame structures in Figures 13 and 14 are merely examples.

[0642] The other symbols in Figures 13 and 14 are symbols equivalent to "preamble signal 252 and control information symbol signal 253 in Figure 21", and therefore, when other symbols 503 in Figure 14 at the same time and on the same frequency (same carrier) as other symbols 403 in Figure 13 transmit control information, they transmit the same data (same control information).

[0643] It is assumed that the receiving device receives the frame in Figure 13 and the frame in Figure 14 simultaneously, but the receiving device can obtain the data transmitted by the transmitting device even if it receives the frame in Figure 13 or the frame in Figure 14.

[0644] Phase changer 209A receives baseband signal 208A and control signal 200, changes the phase of baseband signal 208A based on control signal 200, and outputs phase-changed signal 210A. Baseband signal 208A is a function of symbol number i, expressed as x'(i). Then, phase-changed signal x(i) 210A is expressed as x(i)=e j×ε(i) It can be expressed as ×x'(i), where i is an integer greater than or equal to 0 and j is the imaginary unit.

[0645] The operation of the phase changer 209A may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. The phase changer 209A performs phase change on symbols present in the frequency axis direction. The phase changer 209A performs phase change on data symbols, pilot symbols, control information symbols, etc. At this time, null symbols can also be considered to be targets for phase change.

[0646] Therefore, in this case, the symbol that is the target of symbol number i is a data symbol, a pilot symbol, a control information symbol, a preamble (other symbols), a null symbol, and so on.

[0647] However, since the null symbol has an in-phase component I of zero (0) and an orthogonal component Q of zero (0), even if a phase change is performed on the null symbol, the signal before and after the phase change is the same. Therefore, it is also possible to interpret the null symbol as not being subject to phase change. In the case of Figure 21, phase change unit 209A performs a phase change on baseband signal 208A, and therefore performs a phase change on each symbol shown in Figure 13.

[0648] Therefore, in the frame of Fig. 13, the phase change unit 209A of Fig. 21 applies a phase change to all symbols (other symbols 403) of all carriers at time $1. However, the handling of the phase change of the null symbol 1301 is as explained above.

[0649] Similarly, the phase change unit 209A in FIG. 21 performs phase change on the following symbols: "All symbols of all carriers at time $2 (other symbols 403)" "All symbols of all carriers at time $3 (other symbols 403)" "All symbols of all carriers at time $4 (other symbols 403)" "For all symbols of all carriers at time $5 (pilot symbol 401 or data symbol 402)" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $6" "All symbols of all carriers at time $7 (pilot symbol 401 or data symbol 402)" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $8" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $9" "All symbols of all carriers at time $10 (pilot symbol 401 or data symbol 402)" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $11" However, the handling of the phase change of the null symbol 1301 at all times and all carriers is as explained above. Descriptions of times and carriers other than those mentioned above are omitted.

[0650] The phase change value in phase changer 209A is represented as Ω(i). Baseband signal 208A is x'(i), and phase-changed signal 210A is x(i). Therefore, x(i) = Ω(i) × x'(i) holds.

[0651] For example, the phase change value is set as shown in equation (38). Q is an integer equal to or greater than 2, and Q is the period of the phase change. j is an imaginary unit. However, equation (38) is merely an example and is not limited to this.

[0652] For example, Ω(i) may be set to perform a phase change with a period Q.

[0653] 4 and 13, the same phase change value may be given to the same carrier, and the phase change value may be set for each carrier. For carrier 1 in Figures 4 and 13, the phase change value is set to equation (39) regardless of time. For carrier 2 in Figures 4 and 13, the phase change value is set to equation (40) regardless of time. For carrier 3 in Figures 4 and 13, the phase change value is set to equation (41) regardless of time. 4 and 13, the phase change value is set to equation (42) regardless of time. Descriptions of carriers other than those mentioned above are omitted.

[0654] The above is an example of the operation of the phase changer 209A in FIG.

[0655] The effects obtained by the phase changer 209A in FIG. 21 will be described.

[0656] Other symbols 403, 503 in the "frames of Figs. 4 and 5" or "frames of Figs. 13 and 14" contain control information symbols. As described above, other symbol 503 in Fig. 5, which transmits control information at the same time and on the same frequency (same carrier) as other symbol 403, transmits the same data (same control information).

[0657] Now, consider Case 2, where "control information symbols are transmitted using either antenna unit #A 109_A or antenna unit #B 109_B in FIG. 1."

[0658] When transmitting as in "Case 2," the number of antennas that transmit control information symbols is one, and therefore the spatial diversity gain is smaller than when "control information symbols are transmitted using both antenna unit #A 109_A and antenna unit #B 109_B," and therefore, in "Case 2," the reception quality of data is reduced even when received by the receiving device of Fig. 8. Therefore, in terms of improving the reception quality of data, it is better to "transmit control information symbols using both antenna unit #A 109_A and antenna unit #B 109_B."

[0659] Case 3 is considered where "control information symbols are transmitted using both antenna unit #A 109_A and antenna unit #B 109_B in FIG. 1, but phase change is not performed in phase change unit 209A in FIG. 21."

[0660] When transmitting as in "Case 3," the modulated signal transmitted from antenna unit #A 109_A and the modulated signal transmitted from antenna unit #B 109_B are the same or have a specific phase shift, so depending on the radio wave propagation environment, the receiving device in Figure 8 may receive a very poor signal, and both modulated signals may be affected by the same multipath. This can cause a phenomenon in which the data reception quality in the receiving device in Figure 8 deteriorates.

[0661] To alleviate this phenomenon, phase change unit 209A is provided in Fig. 21. This changes the phase in the time or frequency direction, thereby reducing the possibility of a poorly received signal in the receiving device of Fig. 8. Furthermore, since there is a high possibility that the influence of multipath on the modulated signal transmitted from antenna unit #A 109_A is different from the influence of multipath on the modulated signal transmitted from antenna unit #B 109_B, there is a high possibility that diversity gain can be obtained, thereby improving the data reception quality in the receiving device of Fig. 8.

[0662] For the above reasons, in FIG. 21, a phase change section 209A is provided to change the phase.

[0663] In addition to the control information symbols, other symbols 403 and other symbols 503 include, for example, symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation, in order to demodulate and decode the control information symbols. Also, the "frames of Figures 4 and 5" or the "frames of Figures 13 and 14" include pilot symbols 401 and 501, and by using these, it is possible to demodulate and decode the control information symbols with higher accuracy.

[0664] 4 and 5 or the frames of FIGS. 13 and 14, multiple streams are transmitted or MIMO transmission is performed using the same frequency (same frequency band) and the same time using data symbols 402 and data symbols 502. To demodulate these data symbols, symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation, which are included in other symbols 403 and other symbols 503, are used.

[0665] At this time, the phases of "the symbols for signal detection, the symbols for frequency synchronization and time synchronization, and the symbols for channel estimation included in other symbols 403 and other symbols 503" are changed by phase change unit 209A as described above.

[0666] In such a situation, if this processing is not reflected "on data symbol 402 and data symbol 502," or "in the case of the above explanation, on data symbol 402," when demodulating and decoding data symbol 402 and data symbol 502 in the receiving device, demodulation and decoding must be performed that reflects the processing for the phase change performed in phase change unit 209A, and this processing is likely to become complicated.

[0667] This is because the phases of "symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation included in other symbols 403 and other symbols 503" have been changed by phase change unit 209A.

[0668] However, as shown in FIG. 21, when phase change section 209A performs a phase change on data symbol 402 and data symbol 502 (on data symbol 402 in the above explanation), there is an advantage that the receiving device can (simply) demodulate and decode data symbol 402 and data symbol 502 using a channel estimation signal (a propagation path fluctuation estimation signal) estimated using "other symbols 403 and, which are included in other symbols 503, symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation."

[0669] In addition, as shown in FIG. 21, when phase change section 209A applies a phase change to data symbol 402 and data symbol 502 (in the above description, to data symbol 402), the effect of a sudden drop in field strength on the frequency axis in multipath can be reduced, which may result in an improvement in the reception quality of data for data symbol 402 and data symbol 502.

[0670] In this way, the characteristic feature is that "the target symbols for which phase change is performed by phase change sections 205A and 205B" and "the target symbols for which phase change is performed by phase change section 209A" are different.

[0671] As described above, by performing a phase change using phase change units 205A and 205B in FIG. 21, it is possible to obtain the effect of improving the reception quality of data at the receiving device for data symbol 402 and data symbol 502, for example, in an LOS environment, and by performing a phase change using phase change unit 209A in FIG. 21, it is possible to obtain the effect of improving the reception quality at the receiving device for control information symbols included in, for example, "the frames of FIGS. 4 and 5" or "the frames of FIGS. 13 and 14", and simplifying the operations of demodulating and decoding data symbol 402 and data symbol 502.

[0672] In addition, by performing phase change using phase change units 205A and 205B in Figure 21, it is possible to obtain the effect of improving the reception quality of data at the receiving device for data symbol 402 and data symbol 502, for example, in an LOS environment, and further, by performing phase change on data symbol 402 and data symbol 502 using phase change unit 209A in Figure 21, the reception quality of data symbol 402 and data symbol 502 is improved.

[0673] It should be noted that Q in equation (38) may be an integer equal to or less than −2, and in this case, the period of phase change is the absolute value of Q. This point can also be applied to the first embodiment.

[0674] (Embodiment 6) In this embodiment, a method of implementing a configuration different from that shown in FIG. 2 in the first embodiment will be described.

[0675] FIG. 1 shows an example of the configuration of a transmitting device such as a base station, an access point, or a broadcasting station in this embodiment, and details have been explained in the first embodiment, so explanation will be omitted.

[0676] Signal processing unit 106 receives mapped signals 105_1 and 105_2, signal group 110, and control signal 100 as input, performs signal processing based on control signal 100, and outputs processed signals 106_A and 106_B. Here, processed signal 106_A is represented as u1(i), and processed signal 106_B is represented as u2(i). i is a symbol number, and is an integer equal to or greater than 0, for example. Details of the signal processing will be described with reference to FIG. 22.

[0677] Fig. 22 shows an example of the configuration of signal processing unit 106 in Fig. 1. Weighting combination unit (precoding unit) 203 receives mapped signal 201A (mapped signal 105_1 in Fig. 1), mapped signal 201B (mapped signal 105_2 in Fig. 1), and control signal 200 (control signal 100 in Fig. 1), performs weighting combination (precoding) based on control signal 200, and outputs weighted signal 204A and weighted signal 204B.

[0678] In this case, mapped signal 201A is represented as s1(t), mapped signal 201B as s2(t), weighted signal 204A as z1'(t), and weighted signal 204B as z2'(t). Note that t is, for example, time. s1(t), s2(t), z1'(t), and z2'(t) are defined as complex numbers, and therefore may also be real numbers.

[0679] Here, it is treated as a function of time, but it may be a function of "frequency (carrier number)", or a function of "time and frequency". It may also be a function of "symbol number". This is also the same as in the first embodiment.

[0680] The weighting and combining unit (precoding unit) 203 performs the calculation of equation (49).

[0681] Phase shifter 205A receives weighted and combined signal 204A and control signal 200 as input, performs a phase shift on weighted and combined signal 204A based on control signal 200, and outputs phase-shifted signal 206A. Phase-shifted signal 206A is represented by z1(t), which is defined as a complex number and may also be a real number.

[0682] The specific operation of the phase changer 205A will be described. For example, the phase changer 205A applies a phase change of w(i) to z1'(i). Therefore, it can be expressed as z1(i) = w(i) × z1'(i), where i is the symbol number and is an integer equal to or greater than 0.

[0683] For example, the phase change value is set as shown in equation (50).

[0684] M is an integer equal to or greater than 2, and M is the period of phase change. If M is set to an odd number equal to or greater than 3, there is a possibility that the data reception quality will improve. However, Equation (50) is merely an example, and is not limited to this. Therefore, the phase change value w(i)=e j×λ(i) It is expressed as:

[0685] Phase shifter 205B receives weighted and combined signal 204B and control signal 200 as input, and performs a phase shift on weighted and combined signal 204B based on control signal 200, outputting phase-shifted signal 206B. Phase-shifted signal 206B is represented by z2(t), which is defined as a complex number and may also be a real number.

[0686] The specific operation of the phase changer 205B will be described. For example, the phase changer 205B applies a phase change of y(i) to z2'(i). Therefore, it can be expressed as z2(i) = y(i) × z2'(i), where i is the symbol number and is an integer equal to or greater than 0.

[0687] For example, the phase change value is set as shown in equation (2). N is an integer equal to or greater than 2, and N is the phase change period. N ≠ M is satisfied. If N is set to an odd number equal to or greater than 3, there is a possibility that the data reception quality will improve. However, equation (2) is merely an example, and is not limited to this. Therefore, the phase change value y(i)=e j×δ(i) It is expressed as:

[0688] In this case, z1(i) and z2(i) can be expressed by equation (51).

[0689] Note that δ(i) and λ(i) are real numbers. Then, z1(i) and z2(i) are transmitted from the transmitting device at the same time and at the same frequency (same frequency band). In equation (51), the phase change value is not limited to equations (2) and (51), and a method of periodically and regularly changing the phase is also possible.

[0690] As explained in the first embodiment, the matrices (precoding matrices) in equations (49) and (51) can be equations (5) to (36), etc. However, the precoding matrices are not limited to these. The same applies to the first embodiment.

[0691] Insertion section 207A receives weighted and combined signal 204A, pilot symbol signal pa(t) 251A, preamble signal 252, control information symbol signal 253, and control signal 200 as input, and outputs baseband signal 208A based on the frame configuration, based on the frame configuration information included in control signal 200. t is time.

[0692] Similarly, insertion unit 207B receives phase-shifted signal 206B, pilot symbol signal pb(t) 251B, preamble signal 252, control information symbol signal 253, and control signal 200 as input, and outputs baseband signal 208B based on the frame configuration, based on the frame configuration information included in control signal 200.

[0693] Phase changer 209B receives baseband signal 208B and control signal 200, changes the phase of baseband signal 208B based on control signal 200, and outputs phase-changed signal 210B. Baseband signal 208B is a function of symbol number i (i is an integer equal to or greater than 0), expressed as x'(i). Then, phase-changed signal 210B(x(i)) is expressed as x(i)=e j×ε(i) It can be expressed as ×x'(i), where j is the imaginary unit.

[0694] As explained in the first embodiment and the like, the operation of phase changer 209B may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209B performs phase change on symbols present in the frequency axis direction. Phase changer 209B performs phase change on data symbols, pilot symbols, control information symbols, etc.

[0695] FIG. 3 shows an example of the configuration of the radio units 107_A and 107_B in FIG. 1, and as detailed explanation has been given in the first embodiment, the explanation will be omitted.

[0696] FIG. 4 shows the frame structure of the transmission signal 108_A in FIG. 1, and as detailed explanation has been given in the first embodiment, the explanation will be omitted.

[0697] FIG. 5 shows the frame structure of the transmission signal 108_B in FIG. 1, and as detailed explanation has been given in the first embodiment, the explanation will be omitted.

[0698] When a symbol exists on carrier A, time $B in Figure 4 and a symbol exists on carrier A, time $B in Figure 5, the symbol on carrier A, time $B in Figure 4 and the symbol on carrier A, time $B in Figure 5 are transmitted at the same time and on the same frequency. Note that the frame structure is not limited to Figures 4 and 5, and Figures 4 and 5 are merely examples of frame structures.

[0699] The other symbols in Figures 4 and 5 are symbols corresponding to "preamble signal 252 and control information symbol signal 253 in Figure 2", and therefore, when other symbols 503 in Figure 5 at the same time and on the same frequency (same carrier) as other symbols 403 in Figure 4 transmit control information, they transmit the same data (same control information).

[0700] It is assumed that the receiving device receives the frame in Figure 4 and the frame in Figure 5 simultaneously, but the receiving device can obtain the data transmitted by the transmitting device even if it receives the frame in Figure 4 or the frame in Figure 5.

[0701] FIG. 6 shows an example of the configuration of a portion related to control information generation for generating control information signal 253 in FIG. 2, and as detailed explanation has been given in the first embodiment, explanation thereof will be omitted.

[0702] Fig. 7 shows an example of the configuration of antenna unit #A 109_A and antenna unit #B 109_B in Fig. 1, in which antenna unit #A 109_A and antenna unit #B 109_B are configured with multiple antennas. Fig. 7 has been explained in detail in the first embodiment, so its explanation will be omitted.

[0703] Figure 8 shows an example of the configuration of a receiving device that receives a modulated signal when the transmitting device of Figure 1 transmits a transmission signal having the frame structure of Figures 4 and 5, for example. Since a detailed explanation has been given in embodiment 1, a detailed explanation will be omitted here.

[0704] Fig. 10 shows an example of the configuration of antenna unit #X 801X and antenna unit #Y 801Y in Fig. 8, where antenna unit #X 801X and antenna unit #Y 801Y are configured with multiple antennas. Fig. 10 has been explained in detail in embodiment 1, so its explanation will be omitted.

[0705] Next, as shown in Fig. 1, signal processing unit 106 of the transmitting device is inserted with phase change units 205A, 205B and phase change unit 209B as shown in Fig. 22. The features and effects of this will be described.

[0706] As explained using Figures 4 and 5, phase change sections 205A and 205B perform precoding (weighted combining) on ​​mapped signal s1(i) 201A obtained by mapping using a first sequence and mapped signal s2(i) 201B obtained by mapping using a second sequence, and then perform phase change on the resulting weighted combined signals 204A and 204B, where i is a symbol number and is an integer equal to or greater than 0.

[0707] Then, phase-changed signal 206A and phase-changed signal 206B are transmitted at the same frequency and at the same time. Therefore, in Figures 4 and 5, phase change is applied to data symbol 402 in Figure 4 and data symbol 502 in Figure 5.

[0708] For example, Fig. 11 shows carrier 1 to carrier 5 and time $4 to time $6 extracted from the frame in Fig. 4. Note that Fig. 11 shows pilot symbols 401, data symbols 402, and other symbols 403, just like Fig. 4.

[0709] As described above, in the symbols shown in FIG. 11, phase modification unit 205A applies phase modification to the data symbols at (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6).

[0710] Therefore, the phase change value for the data symbol shown in FIG. 11 is "e j×λ15(i) " and (carrier 2, time $5) "e j×λ25(i) " and (carrier 3, time $5) is "e j×λ35(i) " and (carrier 4, time $5) is "e j×λ45(i) " and (carrier 5, time $5) is "e j×λ55(i) " and (Carrier 1, Time $6) is "e j×λ16(i) " and (carrier 2, time $6) is "e j×λ26(i) " and (carrier 4, time $6) is "e j×λ46(i) " and (carrier 5, time $6) is "e j×λ56(i) "

[0711] On the other hand, in the symbols shown in Figure 11, other symbols in (carrier 1, time $4), (carrier 2, time $4), (carrier 3, time $4), (carrier 4, time $4), and (carrier 5, time $4), and the pilot symbol in (carrier 3, time $6) are not subject to phase modification by phase modification unit 205A.

[0712] This is a characteristic feature of phase changer 205A. Note that, as shown in FIG. 4, data carriers are allocated at the "same carrier, same time" as the data symbols in (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6, (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6), which are the targets of phase change in FIG. 11.

[0713] That is, in Figure 4, (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6) are data symbols.

[0714] That is, data symbols that are subjected to MIMO transmission or that transmit a plurality of streams are the targets of phase modification by phase modification section 205A.

[0715] An example of the phase change that the phase change unit 205A applies to the data symbols is a method of performing regular phase change on the data symbols, that is, a phase change with a period of N, as shown in equation (50). However, the method of changing the phase of the data symbols is not limited to this.

[0716] For example, Fig. 11 shows carrier 1 to carrier 5 and time $4 to time $6 extracted from the frame in Fig. 5. Note that Fig. 11 shows pilot symbols 501, data symbols 502, and other symbols 503, just like Fig. 5.

[0717] As described above, in the symbols shown in FIG. 11, phase change unit 205B applies phase change to the data symbols at (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6).

[0718] Therefore, the phase change value for the data symbol shown in FIG. 11 is "e j×δ15(i) " and (carrier 2, time $5) "e j×δ25(i) " and (carrier 3, time $5) is "e j×δ35(i) " and (carrier 4, time $5) is "e j×δ45(i) " and (carrier 5, time $5) is "e j×δ55(i) " and (Carrier 1, Time $6) is "e j×δ16(i) " and (carrier 2, time $6) is "e j×δ26(i) " and (carrier 4, time $6) is "e j×δ46(i) " and (carrier 5, time $6) is "e j×δ56(i) "

[0719] On the other hand, in the symbols shown in Figure 11, other symbols in (carrier 1, time $4), (carrier 2, time $4), (carrier 3, time $4), (carrier 4, time $4), and (carrier 5, time $4), and the pilot symbol in (carrier 3, time $6) are not subject to phase modification by phase modification unit 205B.

[0720] This is a characteristic feature of phase changer 205B. Note that, as shown in Fig. 4, data carriers are allocated at the "same carrier, same time" as the data symbols in (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6), which are the targets of phase change in Fig. 11.

[0721] That is, in Figure 4, (carrier 1, time $5), (carrier 2, time $5), (carrier 3, time $5), (carrier 4, time $5), (carrier 5, time $5), (carrier 1, time $6), (carrier 2, time $6), (carrier 4, time $6), and (carrier 5, time $6) are data symbols.

[0722] That is, data symbols that are subjected to MIMO transmission or transmission of multiple streams are the targets of phase modification by phase modification section 205B.

[0723] An example of the phase change that the phase change unit 205B applies to the data symbols is a method of performing regular phase change on the data symbols, that is, a phase change with a period of N, as shown in equation (2). However, the method of changing the phase of the data symbols is not limited to this.

[0724] By doing so, in an environment where direct waves are dominant, such as an LOS environment, it is possible to obtain an effect of improving the reception quality of data at a receiving device for data symbols that are transmitting MIMO transmission or multiple streams. This effect will now be explained.

[0725] For example, the modulation scheme used in mapping section 104 in Fig. 1 is QPSK. Mapped signal 201A in Fig. 18 is a QPSK signal, and mapped signal 201B is also a QPSK signal. In other words, two QPSK streams are transmitted.

[0726] Then, in the signal processing unit 811 in FIG. 8, for example, 16 candidate signal points are obtained using the channel estimation signals 806_1 and 806_2. QPSK can transmit 2 bits, and a total of 4 bits are transmitted by two streams. 4 = 16 candidate signal points.

[0727] It should be noted that another 16 candidate signal points can be obtained using channel estimation signals 808_1 and 808_2, but the explanation would be similar, so we will focus on the 16 candidate signal points obtained using channel estimation signals 806_1 and 806_2 and proceed with the explanation.

[0728] An example of this state is shown in Figure 12. In both Figures 12A and 12B, the horizontal axis is in-phase I and the vertical axis is quadrature Q, and there are 16 candidate signal points on the in-phase I-quadrature Q plane. One of the 16 candidate signal points is the signal point transmitted by the transmitting device. For this reason, they are called "16 candidate signal points."

[0729] In an environment where direct waves are dominant, for example, an LOS environment, the first case is considered as "a case where phase change units 205A and 205B of FIG. 22 do not exist, that is, a case where phase change units 205A and 205B of FIG. 22 do not perform phase change."

[0730] In the "first case," no phase change is performed, which may result in the state shown in Fig. 12A. When the state shown in Fig. 12A occurs, there are areas where signal points are densely packed, such as "signal points 1201 and 1202," "signal points 1203, 1204, 1205 and 1206," and "signal points 1207 and 1208," which may result in a decrease in data reception quality in the receiving device of Fig. 8.

[0731] To overcome this phenomenon, phase shifters 205A and 205B are inserted in Fig. 22. When phase shifters 205A and 205B are inserted, symbol number i will contain a mixture of symbol numbers where "areas where signal points are densely packed" as shown in Fig. 12A and symbol numbers where "the distance between signal points is long" as shown in Fig. 12B. To address this situation, error correction coding is introduced, making it possible to obtain high error correction capabilities and high data reception quality in the receiving device of Fig. 8.

[0732] 22, phase change sections 205A and 205B in Fig. 22 do not change the phase of "pilot symbols and preambles" used for channel estimation to demodulate (detect) data symbols, such as pilot symbols and preambles. This makes it possible to achieve, in data symbols, "a mixture of symbol numbers where "areas where signal points are densely packed" as shown in Fig. 12A and symbol numbers where "the distance between signal points is long" as shown in Fig. 12B, depending on symbol number i."

[0733] However, even if phase change units 205A and 205B in FIG. 22 change the phase of "pilot symbols and preambles" used for channel estimation to demodulate (detect) data symbols, there are cases where "in data symbols, it is possible to achieve a mixture of symbol numbers where "areas where signal points are densely packed" as shown in FIG. 12A and symbol numbers where "the distance between signal points is long" as shown in FIG. 12B, depending on symbol number i."

[0734] In this case, some conditions must be imposed on the phase change of the pilot symbols and preambles. For example, a method can be considered in which a different rule is established from the rule for phase change of the data symbols, and "phase change is applied to the pilot symbols and / or preambles." For example, there is a method in which phase change is applied to the data symbols regularly with a period of N, and phase change is applied to the pilot symbols and / or preambles regularly with a period of M. N and M are integers equal to or greater than 2.

[0735] As described above, phase changer 209A receives baseband signal 208A and control signal 200 as input, changes the phase of baseband signal 208A based on control signal 200, and outputs phase-changed signal 210A. Baseband signal 208A is a function of symbol number i, expressed as x'(i). Then, phase-changed signal x(i) 210A is expressed as x(i)=e j×ε(i) It can be expressed as ×x'(i), where i is an integer greater than or equal to 0 and j is the imaginary unit.

[0736] The operation of phase changer 209A may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209A performs phase change on symbols present in the frequency axis direction. Phase changer 209A performs phase change on data symbols, pilot symbols, control information symbols, etc.

[0737] Therefore, in this case, the symbols targeted by symbol number i are data symbols, pilot symbols, control information symbols, preambles (other symbols), etc. In the case of Fig. 22, phase change unit 209A applies a phase change to baseband signal 208A, and therefore applies a phase change to each symbol shown in Fig. 4.

[0738] Therefore, in the frame of FIG. 4, phase change section 209A of FIG. 22 applies phase change to all symbols (other symbols 403) of all carriers at time $1.

[0739] Similarly, the phase change unit 209A in FIG. 22 performs phase change on the following symbols: "All symbols of all carriers at time $2 (other symbols 403)" "All symbols of all carriers at time $3 (other symbols 403)" "All symbols of all carriers at time $4 (other symbols 403)" "All symbols (pilot symbol 401 or data symbol 402) of all carriers at time $5" "All symbols (pilot symbol 401 or data symbol 402) of all carriers at time $6" "All symbols (pilot symbol 401 or data symbol 402) of all carriers at time $7" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $8" "All symbols (pilot symbol 401 or data symbol 402) of all carriers at time $9" "All symbols (pilot symbol 401 or data symbol 402) of all carriers at time $10" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $11"; descriptions of times and carriers other than those mentioned above are omitted.

[0740] As described above, phase changer 209B receives baseband signal 208B and control signal 200 as input, changes the phase of baseband signal 208B based on control signal 200, and outputs phase-changed signal 210B. Baseband signal 208B is a function of symbol number i, expressed as y'(i). Then, phase-changed signal y(i) 210B is expressed as y(i)=e j×η(i) It can be expressed as ×y'(i), where i is an integer greater than or equal to 0, and j is the imaginary unit.

[0741] The operation of phase changer 209B may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209B performs phase change on symbols present in the frequency axis direction. Phase changer 209B performs phase change on data symbols, pilot symbols, control information symbols, etc.

[0742] Therefore, in this case, the symbols targeted by symbol number i are data symbols, pilot symbols, control information symbols, preambles (other symbols), etc. In the case of Fig. 22, phase change unit 209B applies a phase change to baseband signal 208B, and therefore applies a phase change to each symbol shown in Fig. 5.

[0743] Therefore, in the frame of FIG. 5, phase change section 209B of FIG. 22 applies phase change to all symbols (other symbols 503) of all carriers at time $1.

[0744] Similarly, the phase change unit 209B in FIG. 22 performs phase change on the following symbols: "All symbols of all carriers at time $2 (other symbols 503)" "All symbols of all carriers at time $3 (other symbols 503)" "All symbols of all carriers at time $4 (other symbols 503)" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $5" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $6" "All symbols of all carriers at time $7 (pilot symbol 501 or data symbol 502)" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $8" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $9" "All symbols of all carriers at time $10 (pilot symbol 501 or data symbol 502)" "All symbols (pilot symbol 501 or data symbol 502) of all carriers at time $11"; times and carriers other than those mentioned above are omitted.

[0745] FIG. 13 shows a frame configuration different from that of FIG. 4 of the transmission signal 108_A in FIG. 1, and as detailed explanation has been given in the first embodiment, explanation will be omitted.

[0746] FIG. 14 shows a frame configuration different from that of FIG. 5 of the transmission signal 108_B in FIG. 1, and as detailed explanation has been given in the first embodiment, explanation will be omitted.

[0747] When a symbol exists on carrier A, time $B in Figure 13 and a symbol exists on carrier A, time $B in Figure 14, the symbol on carrier A, time $B in Figure 13 and the symbol on carrier A, time $B in Figure 14 are transmitted at the same time and on the same frequency. Note that the frame structures in Figures 13 and 14 are merely examples.

[0748] The other symbols in Figures 13 and 14 are symbols equivalent to "preamble signal 252 and control information symbol signal 253 in Figure 22", and therefore, when other symbols 503 in Figure 14 at the same time and on the same frequency (same carrier) as other symbols 403 in Figure 13 transmit control information, they transmit the same data (same control information).

[0749] It is assumed that the receiving device receives the frame in Figure 13 and the frame in Figure 14 simultaneously, but the receiving device can obtain the data transmitted by the transmitting device even if it receives the frame in Figure 13 or the frame in Figure 14.

[0750] Phase changer 209A receives baseband signal 208A and control signal 200, changes the phase of baseband signal 208A based on control signal 200, and outputs phase-changed signal 210A. Baseband signal 208A is a function of symbol number i, expressed as x'(i). Then, phase-changed signal x(i) 210A is expressed as x(i)=e j×ε(i) It is expressed as ×x'(i), where i is an integer greater than or equal to 0, and j is the imaginary unit.

[0751] The operation of phase changer 209A may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209A performs phase change on symbols present in the frequency axis direction. Phase changer 209A performs phase change on data symbols, pilot symbols, control information symbols, etc.

[0752] In this case, null symbols can also be considered to be targets of phase change. Therefore, in this case, the symbols targeted by symbol number i include data symbols, pilot symbols, control information symbols, preambles (other symbols), null symbols, etc.

[0753] However, since the null symbol has an in-phase component I of zero (0) and a quadrature component Q of zero (0), even if a phase change is performed on the null symbol, the signal before and after the phase change is the same.

[0754] Therefore, it is also possible to interpret that the null symbols are not subject to phase modification. In the case of Fig. 22, phase modification section 209A performs a phase modification on baseband signal 208A, and therefore performs a phase modification on each symbol shown in Fig. 13.

[0755] Therefore, in the frame of Fig. 13, the phase change unit 209A of Fig. 22 applies a phase change to all symbols (other symbols 403) of all carriers at time $1. However, the handling of the phase change of the null symbol 1301 is as explained above.

[0756] Similarly, the phase change unit 209A in FIG. 22 performs phase change on the following symbols: "All symbols of all carriers at time $2 (other symbols 403)" "All symbols of all carriers at time $3 (other symbols 403)" "All symbols of all carriers at time $4 (other symbols 403)" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $5" "All symbols of all carriers at time $6 (pilot symbols 401 or data symbols 402)" "All symbols of all carriers at time $7 (pilot symbol 401 or data symbol 402)" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $8" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $9" "All symbols of all carriers at time $10 (pilot symbol 401 or data symbol 402)" "All symbols (pilot symbols 401 or data symbols 402) of all carriers at time $11." However, the handling of the phase change of the null symbol 1301 at all times and all carriers is as explained above. Descriptions of times and carriers other than those mentioned above are omitted.

[0757] The phase change value in phase changer 209A is represented as Ω(i). Baseband signal 208A is x'(i), and phase-changed signal 210A is x(i). Therefore, x(i) = Ω(i) × x'(i) holds.

[0758] For example, the phase change value is set as shown in equation (38). Q is an integer equal to or greater than 2, and Q is the period of the phase change. j is an imaginary unit. However, equation (38) is merely an example and is not limited to this.

[0759] For example, Ω(i) may be set to perform a phase change with a period Q.

[0760] 4 and 13, the same phase change value may be given to the same carrier, and the phase change value may be set for each carrier. For carrier 1 in Figures 4 and 13, the phase change value is set to equation (39) regardless of time. For carrier 2 in Figures 4 and 13, the phase change value is set to equation (40) regardless of time. For carrier 3 in Figures 4 and 13, the phase change value is set to equation (41) regardless of time. 4 and 13, the phase change value is set to Equation (42) regardless of time. Descriptions of carriers other than those mentioned above are omitted.

[0761] The above is an example of the operation of the phase changer 209A in FIG.

[0762] Phase changer 209B receives baseband signal 208B and control signal 200, changes the phase of baseband signal 208B based on control signal 200, and outputs phase-changed signal 210B. Baseband signal 208B is a function of symbol number i, expressed as y'(i). Then, phase-changed signal x(i) 210B is expressed as y(i)=e j×η(i) ×y'(i), where i is an integer greater than or equal to 0 and j is the imaginary unit.

[0763] The operation of phase changer 209B may be CDD / CSD as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209B performs phase change on symbols present in the frequency axis direction. Phase changer 209B performs phase change on data symbols, pilot symbols, control information symbols, etc.

[0764] In this case, null symbols can also be considered to be targets of phase change. Therefore, in this case, the symbols targeted by symbol number i include data symbols, pilot symbols, control information symbols, preambles (other symbols), null symbols, etc.

[0765] However, since the null symbol has an in-phase component I of zero (0) and an orthogonal component Q of zero (0), even if a phase change is performed on the null symbol, the signal before and after the phase change is the same. Therefore, it is also possible to interpret the null symbol as not being subject to phase change. In the case of Figure 22, phase change unit 209B performs a phase change on baseband signal 208B, and therefore performs a phase change on each symbol shown in Figure 14.

[0766] Therefore, in the frame of Fig. 14, the phase change unit 209B of Fig. 22 applies a phase change to all symbols (other symbols 503) of all carriers at time $1. However, the handling of the phase change of the null symbol 1301 is as explained above.

[0767] Similarly, the phase change unit 209B in FIG. 22 performs phase change on the following symbols: "All symbols of all carriers at time $2 (other symbols 503)" "All symbols of all carriers at time $3 (other symbols 503)" "All symbols of all carriers at time $4 (other symbols 503)" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $5" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $6" "All symbols (pilot symbol 501 or data symbol 502) of all carriers at time $7" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $8" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $9" "All symbols (pilot symbol 501 or data symbol 502) of all carriers at time $10" "All symbols (pilot symbols 501 or data symbols 502) of all carriers at time $11", however, the handling of the phase change of the null symbol 1301 at all times and all carriers is as explained above. Descriptions of times and carriers other than those mentioned above are omitted.

[0768] The phase change value in phase changer 209B is represented as Δ(i). Baseband signal 208B is y'(i), and phase-changed signal 210B is y(i). Therefore, y(i) = Δ(i) × y'(i) holds.

[0769] For example, the phase change value is set as in equation (49), where R is an integer equal to or greater than 2 and represents the period of the phase change. Note that it is preferable that the values ​​of Q and R in equation (38) are different.

[0770] For example, Δ(i) may be set to change the phase to have a period R.

[0771] 5 and 14, the same phase change value may be given to the same carrier, and the phase change value may be set for each carrier. For carrier 1 in Figures 5 and 14, the phase change value is set to equation (39) regardless of time. For carrier 2 in Figures 5 and 14, the phase change value is set to equation (40) regardless of time. For carrier 3 in Figures 5 and 14, the phase change value is set to equation (41) regardless of time. 5 and 14, the phase change value is set to Equation (42) regardless of time. Descriptions of carriers other than those mentioned above are omitted.

[0772] The above is an example of the operation of the phase changer 209B in FIG.

[0773] The effects obtained by the phase change units 209A and 209B in FIG. 22 will be described.

[0774] Other symbols 403, 503 in the "frames of Figs. 4 and 5" or "frames of Figs. 13 and 14" contain control information symbols. As described above, other symbol 503 in Fig. 5, which transmits control information at the same time and on the same frequency (same carrier) as other symbol 403, transmits the same data (same control information).

[0775] Now, consider Case 2, where "control information symbols are transmitted using either antenna unit #A 109_A or antenna unit #B 109_B in FIG. 1."

[0776] When transmitting as in "Case 2," the number of antennas that transmit control information symbols is one, and therefore the spatial diversity gain is smaller than when "control information symbols are transmitted using both antenna unit #A 109_A and antenna unit #B 109_B," and therefore, in "Case 2," the reception quality of data is reduced even when received by the receiving device of Fig. 8. Therefore, in terms of improving the reception quality of data, it is better to "transmit control information symbols using both antenna unit #A 109_A and antenna unit #B 109_B."

[0777] As Case 3, consider the case where "control information symbols are transmitted using both antenna unit #A 109_A and antenna unit #B 109_B in FIG. 1, but no phase change is performed in phase change units 209A and 209B in FIG. 22."

[0778] When transmitting as in "Case 3," the modulated signal transmitted from antenna unit #A 109_A and the modulated signal transmitted from antenna unit #B 109_B are the same or have a specific phase shift, so depending on the radio wave propagation environment, the receiving device in Figure 8 may receive a very poor signal, and both modulated signals may be affected by the same multipath. This can cause a phenomenon in which the data reception quality in the receiving device in Figure 8 deteriorates.

[0779] To alleviate this phenomenon, phase shifters 209A and 209B are provided in Fig. 22. This shifts the phase in the time or frequency direction, thereby reducing the possibility of poor reception signals in the receiving device of Fig. 8. Furthermore, since there is a high possibility that the influence of multipath on the modulated signal transmitted from antenna unit #A 109_A is different from the influence of multipath on the modulated signal transmitted from antenna unit #B 109_B, there is a high possibility that diversity gain can be obtained, thereby improving the data reception quality in the receiving device of Fig. 8.

[0780] For the above reasons, in FIG. 22, phase change sections 209A and 209B are provided to perform phase change.

[0781] In addition to the control information symbols, other symbols 403 and other symbols 503 include, for example, symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation, in order to demodulate and decode the control information symbols. Also, the "frames of Figures 4 and 5" or the "frames of Figures 13 and 14" include pilot symbols 401 and 501, and by using these, it is possible to demodulate and decode the control information symbols with higher accuracy.

[0782] 4 and 5 or the frames of FIGS. 13 and 14, multiple streams are transmitted or MIMO transmission is performed using the same frequency (frequency band) and the same time using data symbols 402 and data symbols 502. To demodulate these data symbols, symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation, which are included in other symbols 403 and other symbols 503, are used.

[0783] At this time, the phases of "symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation included in other symbols 403 and other symbols 503" are changed by phase change units 209A and 209B as described above.

[0784] In such a situation, if this processing is not reflected on data symbol 402 and data symbol 502 (in the case of the above explanation, on data symbol 402), when demodulating and decoding data symbol 402 and data symbol 502 in the receiving device, demodulation and decoding must be performed that reflects the processing for the phase change performed by phase change unit 209A, and this processing is likely to become complicated.

[0785] This is because the phases of "symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation included in other symbols 403 and other symbols 503" have been changed by phase change units 209A and 209B.

[0786] However, as shown in FIG. 22, when phase change units 209A and 209B change the phase of data symbol 402 and data symbol 502, the receiving device can easily demodulate and decode data symbol 402 and data symbol 502 using a channel estimation signal (a propagation path fluctuation estimation signal) estimated using "other symbols 403 and, which are included in other symbols 503, symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation."

[0787] In addition, as shown in FIG. 22, when phase shifting units 209A and 209B perform phase shifting on data symbol 402 and data symbol 502, the effect of a sudden drop in field strength on the frequency axis in multipath can be reduced, which may result in an improvement in the reception quality of data for data symbol 402 and data symbol 502.

[0788] In this way, the characteristic point is that "the target symbols for which phase change is performed by phase change sections 205A and 205B" and "the target symbols for which phase change is performed by phase change sections 209A and 209B" are different.

[0789] As described above, by performing a phase change using phase change unit 205B in FIG. 22, it is possible to obtain the effect of improving the reception quality of data at the receiving device for data symbol 402 and data symbol 502, for example, in an LOS environment, and by performing a phase change using phase change units 209A and 209B in FIG. 22, it is possible to obtain the effect of improving the reception quality at the receiving device for control information symbols included in, for example, "the frames of FIGS. 4 and 5" or "the frames of FIGS. 13 and 14", and simplifying the operations of demodulating and decoding data symbol 402 and data symbol 502.

[0790] In addition, by performing phase change using phase change units 205A and 205B in Figure 22, it is possible to obtain the effect of improving the reception quality of data at the receiving device for data symbol 402 and data symbol 502, for example, in an LOS environment, and further, by performing phase change using phase change units 209A and 209B in Figure 22 for data symbol 402 and data symbol 502, the reception quality of data symbol 402 and data symbol 502 is improved.

[0791] It should be noted that Q in equation (38) may be an integer equal to or less than −2, and in this case, the period of phase change is the absolute value of Q. This point can also be applied to the first embodiment.

[0792] In addition, R in equation (49) may be an integer equal to or less than −2, and in this case, the period of phase change is the absolute value of R.

[0793] Furthermore, taking into consideration the contents explained in Supplementary Note 1, it is advisable to set the amount of cyclic delay set in phase changer 209A and the amount of cyclic delay set in phase changer 209B to different values.

[0794] (Embodiment 7) In this embodiment, an example of a communication system using the transmission method and reception method described in the first to sixth embodiments will be described.

[0795] FIG. 23 shows an example of the configuration of a base station or an access point in this embodiment.

[0796] Transmitting device 2303 receives data 2301, signal group 2302, and control signal 2309 as input, generates modulated signals corresponding to data 2301 and signal group 2302, and transmits the modulated signals from an antenna.

[0797] In this case, an example of the configuration of transmitting device 2303 is as shown in FIG. 1, where data 2301 corresponds to data 101 in FIG. 1, signal group 2302 corresponds to signal group 110 in FIG. 1, and control signal 2309 corresponds to control signal 100 in FIG. 1.

[0798] Receiving device 2304 receives a modulated signal transmitted by a communication partner, for example, a terminal, performs signal processing, demodulation, and decoding on this modulated signal, and outputs control information signal 2305 from the communication partner and received data 2306.

[0799] In this case, an example of the configuration of the receiving device 2304 is as shown in FIG. 8, where the received data 2306 corresponds to the received data 812 in FIG. 8, and the control information signal 2305 from the communication partner corresponds to the control signal 810 in FIG. 8.

[0800] Control signal generating section 2308 receives control information signal 2305 from the communication partner and setting signal 2307 as input, and generates and outputs control signal 2309 based on these.

[0801] FIG. 24 shows an example of the configuration of a terminal that is a communication partner of the base station in FIG.

[0802] Transmitting device 2403 receives data 2401, signal group 2402, and control signal 2409 as input, generates modulated signals corresponding to data 2401 and signal group 2402, and transmits the modulated signals from an antenna.

[0803] In this case, an example of the configuration of transmitting device 2403 is as shown in FIG. 1, where data 2401 corresponds to data 101 in FIG. 1, signal group 2402 corresponds to signal group 110 in FIG. 1, and control signal 2409 corresponds to control signal 100 in FIG. 1.

[0804] The receiving device 2404 receives a modulated signal transmitted by a communication partner, for example, a base station, performs signal processing, demodulation, and decoding on this modulated signal, and outputs a control information signal 2405 from the communication partner and received data 2406.

[0805] In this case, an example of the configuration of the receiving device 2404 is as shown in FIG. 8, where the received data 2406 corresponds to the received data 812 in FIG. 8, and the control information signal 2405 from the communication partner corresponds to the control signal 810 in FIG. 8.

[0806] Control signal generating section 2408 receives control information signal 2305 from the communication partner and setting signal 2407 as input, and generates and outputs control signal 2409 based on this information.

[0807] Fig. 25 shows an example of a frame configuration of a modulated signal transmitted by the terminal of Fig. 24, with the horizontal axis representing time. Preamble 2501 is a symbol used by a communication partner (e.g., a base station) to perform signal detection, frequency synchronization, time synchronization, frequency offset estimation, and channel estimation, and is, for example, a PSK symbol. It may also include training symbols for directivity control. Note that although it is called a preamble here, it may be called by other names.

[0808] FIG. 25 shows control information symbols 2502 and data symbols 2503 containing data to be transmitted to the other party.

[0809] The control information symbol 2502 includes, for example, the error correction coding method used to generate the data symbol 2503, such as the code length (block length), coding rate information, modulation method information, and control information to notify the communication partner.

[0810] Note that Figure 25 is merely an example of a frame configuration, and is not limited to this frame configuration. Furthermore, other symbols, such as pilot symbols and reference symbols, may be included among the symbols shown in Figure 25. In Figure 25, the vertical axis may represent frequency, and symbols may exist in the frequency axis direction (carrier direction).

[0811] An example of a frame configuration transmitted by the base station in Fig. 23 is as explained using Fig. 4, Fig. 5, Fig. 13, and Fig. 14, and detailed explanation will be omitted here. Note that other symbols 403 and 503 may include training symbols for directivity control. Therefore, this embodiment includes cases where the base station transmits multiple modulated signals using multiple antennas.

[0812] In the above communication system, the operation of the base station will be described in detail below.

[0813] Transmitting device 2303 of the base station in FIG. 23 has the configuration shown in FIG. 1. Signal processing unit 106 in FIG. 1 has the configuration shown in any one of FIGS. 2, 18, 19, 20, 21, 22, 28, 29, 30, 31, 32, and 33. Note that FIGS. 28, 29, 30, 31, 32, and 33 will be explained later. At this time, the operation of phase shifters 205A and 205B may be switched depending on the communication environment and setting status. Control information related to the operation of phase shifters 205A and 205B is transmitted by the base station as part of the control information transmitted in the control information symbols of other symbols 403 and 503 in frame configurations shown in FIGS. 4, 5, 13, and 14.

[0814] In this case, control information related to the operation of phase shifters 205A and 205B is denoted by u0 and u1. The relationship between [u0 u1] and phase shifters 205A and 205B is shown in Table 1. Note that u0 and u1 are transmitted by, for example, the base station as part of the control information symbols of other symbols 403 and 503. The terminal then obtains [u0 u1] included in the control information symbols of other symbols 403 and 503, learns the operation of phase shifters 205A and 205B from [u0 u1], and demodulates and decodes the data symbols.

[0815] [Table 1]

[0816] The interpretation of Table 1 is as follows. When the base station sets "phase change units 205A and 205B do not change the phase," it sets "u0=0, u1=0." Therefore, phase change unit 205A outputs signal 206A without changing the phase of input signal (204A). Similarly, phase change unit 205B outputs signal 206B without changing the phase of input signal 204B. When the base station sets "the phase change units 205A and 205B periodically / regularly change the phase for each symbol," "u0=0, u1=1" are set. Details of how the phase change units 205A and 205B periodically / regularly change the phase for each symbol are as explained in the first to sixth embodiments, and therefore detailed explanation will be omitted. When the signal processing unit 106 in FIG. 1 has the configuration of any of FIG. 20, FIG. 21, and FIG. 22, "u0=0, u1=1" are also set when "the phase change unit 205A periodically / regularly changes the phase for each symbol, and the phase change unit 205B does not periodically / regularly change the phase for each symbol" or "the phase change unit 205A does not periodically / regularly change the phase for each symbol, and the phase change unit 205B periodically / regularly changes the phase for each symbol." When the base station sets "phase change units 205A and 205B perform phase change with a specific phase change value," it sets "u0=1, u1=0." Here, we will explain what "performing phase change with a specific phase change value" means.

[0817] For example, in the phase change unit 205A, a phase change is performed with a specific phase change value. At this time, the input signal (204A) is assumed to be z1(i), where i is the symbol number. Then, when "a phase change is performed with a specific phase change value", the output signal 206A is expressed as e jα ×z1(i), where α is a real number and represents a specific phase change value. At this time, the amplitude may be changed, and in this case, the output signal 206A is expressed as A×e jα ×z1(i), where A is a real number.

[0818] Similarly, in the phase change unit 206A, a phase change is performed with a specific phase change value. At this time, the input signal 204B is assumed to be z2(t), where i is the symbol number. Then, when "a phase change is performed with a specific phase change value", the output signal 206B is expressed as e jβ ×z2(i), where α is a real number and represents a specific phase change value. At this time, the amplitude may be changed, and in this case, the output signal 206B is expressed as B×e jβ ×z2(i), where B is a real number.

[0819] In addition, when the signal processing unit 106 in Figure 1 has any of the configurations in Figures 20, 21, 22, 31, 32, and 33, "u0=1, u1=0" is set even when "the phase change unit 205A applies a phase change with a specific phase change value, and the phase change unit 205B does not apply a phase change with a specific phase change value" or "the phase change unit 205A does not apply a phase change with a specific phase change value, and the phase change unit 205B applies a phase change with a specific phase change value."

[0820] Next, examples of methods for setting the "specific phase change value" will be described. Below, a first method and a second method will be described.

[0821] First method: The base station transmits training symbols. Then, the communicating terminal transmits information about a "specific phase change value (set)" to the base station using the training symbols. The base station performs phase changes based on the information about the "specific phase change value (set)" received from the terminal.

[0822] Alternatively, the base station transmits training symbols. Then, the communicating terminal transmits information about the reception results of the training symbols (e.g., information about channel estimation values) to the base station. The base station determines a suitable value for a "specific phase change value (set)" from the "information about the reception results of the training symbols" obtained from the terminal, and performs the phase change.

[0823] The base station needs to notify the terminal of information regarding the value of the "specific phase change value (set)" that it has set. In this case, the control information symbols in the other symbols 403 and 503 in Figures 4, 5, 13, and 14 transmit information regarding the value of the "specific phase change value (set)" that the base station has set.

[0824] An example of the first method will be described with reference to Figure 26. (A) in Figure 26 shows symbols on the time axis transmitted by the base station, with the horizontal axis representing time. (B) in Figure 26 shows symbols on the time axis transmitted by the terminal, with the horizontal axis representing time.

[0825] The following is a specific explanation of Fig. 26. First, the terminal makes a communication request to the base station.

[0826] Then, the base station transmits at least training symbols 2601 for "estimating a specific phase change value (set) that the base station will use to transmit data symbols 2604." Note that the terminal may use training symbols 2601 to perform other estimations, and training symbols 2601 may be modulated, for example, using PSK modulation. The training symbols are transmitted from multiple antennas, similar to the pilot symbols described in the first to sixth embodiments.

[0827] The terminal receives training symbols 2601 transmitted by the base station, uses the training symbols 2601 to calculate suitable "specific phase change values ​​(set)" to be applied by phase change units 205A and / or 205B provided in the base station, and transmits feedback information symbols 2602 including the calculated values.

[0828] The base station receives the feedback information symbol 2602 transmitted by the terminal, demodulates and decodes the symbol, and obtains information on a suitable "specific phase change value (set)." Based on this information, the phase change value (set) to be applied by the phase change unit 205A and / or the phase change unit 205B of the base station is set.

[0829] The base station then transmits control information symbols 2603 and data symbols 2604, and at least the phase of data symbols 2604 is changed according to the set phase change value (set).

[0830] In data symbol 2604, the base station transmits a plurality of modulated signals from a plurality of antennas, as explained in embodiments 1 to 6. However, unlike embodiments 1 to 6, phase change unit 205A and / or phase change unit 205B performs phase change using the "specific phase change value (set)" explained above.

[0831] The frame configurations of the base station and terminal in Figure 26 are merely examples, and other symbols may be included. Each of the training symbols 2601, feedback information symbols 2602, control information symbols 2603, and data symbols 2604 may include other symbols such as pilot symbols. Furthermore, the control information symbols 2603 include information regarding the value of the "specific phase change value (set)" used when transmitting the data symbols 2604, and by obtaining this information, the terminal can demodulate and decode the data symbols 2604.

[0832] As in the explanations of the first to sixth embodiments, for example, when a base station transmits a modulated signal with a frame configuration such as that shown in Figures 4, 5, 13, and 14, the phase change performed by the "specific phase change value (set)" performed by phase change unit 205A and / or phase change unit 205B described above is performed on data symbols (402, 502). Then, as in the explanations of the first to sixth embodiments, the symbols that are the targets of the phase change performed by phase change unit 209A and / or phase change unit 209B are "pilot symbols 401, 501" and "other symbols 403, 503."

[0833] However, even if the phase change unit 205A and / or the phase change unit 205B also performs phase change on the "pilot symbols 401, 501" and "other symbols 403, 503", demodulation and decoding are possible.

[0834] Note that the phrase "specific phase change values ​​(set)" is used. In the cases of Figures 2, 18, 19, 31, 32, and 33, phase change unit 205A does not exist, but phase change unit 205B does. Therefore, in these cases, it is necessary to prepare specific phase change values ​​to be used in phase change unit 205B. On the other hand, in the cases of Figures 20, 21, 22, 31, 32, and 33, phase change unit 205A and phase change unit 205B exist. In these cases, it is necessary to prepare specific phase change value #A to be used in phase change unit 205A and specific phase change value #B to be used in phase change unit 205B. Accordingly, the phrase "specific phase change values ​​(set)" is used.

[0835] Second method: The base station starts transmitting a frame to the terminal. At this time, the base station sets the value of a "specific phase change value (set)" based on, for example, the value of a random number, performs a phase change with the specific phase change value, and transmits a modulated signal.

[0836] The terminal then transmits information indicating that the frame or packet was not received to the base station, and the base station receives this information.

[0837] The base station then sets a value (set of specific phase change values) for the "specific phase change value" based on, for example, the value of a random number, and transmits a modulated signal. At this time, at least data symbols including data of the frame (packet) that the terminal was unable to obtain are transmitted by a modulated signal in which the phase has been changed based on the reset "specific phase change value (set)." In other words, when the base station transmits data of the first frame (packet) twice (or more times) by retransmitting the data, it is preferable that the "specific phase change value (set)" used in the first transmission and the "specific phase change value (set)" used in the second transmission are different. This has the effect of increasing the probability that the terminal will obtain the frame or packet in the second transmission in the case of a retransmission.

[0838] Thereafter, if the base station receives "information that a frame or packet was not received" from the terminal, it changes the value of the "specific change value (set)" based on, for example, the value of a random number.

[0839] The base station needs to notify the terminal of information regarding the value of the "specific phase change value (set)" that it has set. In this case, the control information symbols in the other symbols 403 and 503 in Figures 4, 5, 13, and 14 transmit information regarding the value of the "specific phase change value (set)" that the base station has set.

[0840] In the second method described above, it was stated that "the base station sets the value of the 'specific phase change value (set)', for example, based on the value of a random number," but the setting of the 'specific phase change value (set)' is not limited to this method, and the 'specific phase change value (set)' may be set by any method as long as the configuration allows the 'specific phase change value (set)' to be newly set when setting the 'specific phase change value (set)'. For example, -Setting a "specific phase change value (set)" based on a certain rule. Randomly set a specific phase change value. - Set a specific phase change value (set) based on information obtained from the communication partner. The "specific phase change value (set)" may be set by any of the above methods, but is not limited to these.

[0841] An example of the second method will be described with reference to Figure 27. (A) in Figure 27 shows symbols on the time axis transmitted by the base station, with the horizontal axis representing time. (B) in Figure 27 shows symbols on the time axis transmitted by the terminal, with the horizontal axis representing time.

[0842] A specific description of FIG. 27 will be given below.

[0843] First, in order to explain FIG. 27, explanation will be given on FIGS. 28, 29, 30, 31, 32, and 33.

[0844] As an example of the configuration of the signal processing unit 106 in FIG. 1, the configurations shown in FIGS. 2, 18, 19, 20, 21, and 22 are shown, and modified configurations thereof are shown in FIGS. 28, 29, 30, 31, 32, and 33.

[0845] 28 is an example in which phase change section 205B is inserted before weighting synthesis section 203 in the configuration of FIG. 2. Next, only the parts of the operation of FIG. 28 that are different from FIG.

[0846] Phase change section 205B receives mapped signal s2(t) 201B and control signal 200 as input, performs a phase change on mapped signal 201B based on control signal 200, and outputs phase-changed signal 2801B.

[0847] Phase change section 205B, for example, applies a phase change of y(i) to s2(i). Therefore, if signal 2801B after the phase change is s2'(i), then s2'(i)=y(i)×s2(i), where i is the symbol number and is an integer equal to or greater than 0. Note that the method of assigning y(i) is as explained in embodiment 1.

[0848] Weighting combination section 203 receives mapped signal s1(i) 201A, phase-changed signal s2'(i) 2801B, and control signal 200 as input, performs weighting combination (precoding) based on control signal 200, and outputs weighted combined signal 204A and weighted combined signal 204B. Specifically, a vector formed by mapped signal s1(i) 201A and phase-changed signal s2'(i) 2801B is multiplied by a precoding matrix to obtain weighted combined signal 204A and weighted combined signal 204B. Note that an example of the configuration of the precoding matrix is ​​as described in embodiment 1. The following description is the same as that in FIG. 2, and therefore will not be repeated.

[0849] Fig. 29 shows an example in which, in the configuration of Fig. 18, phase modification section 205B is inserted before weighting synthesis section 203. In this case, the operations of phase modification section 205B and weighting synthesis section 203 have been explained in the explanation of Fig. 28, so explanations thereof will be omitted. Furthermore, the operations of weighting synthesis section 203 and subsequent sections are the same as those explained in Fig. 18, so explanations thereof will be omitted.

[0850] Fig. 30 shows an example in which, in the configuration of Fig. 19, phase modification section 205B is inserted before weighting synthesis section 203. In this case, the operations of phase modification section 205B and weighting synthesis section 203 have been explained in Fig. 28, so explanations thereof will be omitted. Furthermore, the operations of weighting synthesis section 203 and subsequent sections will be omitted, as they are the same as those explained in Fig. 19.

[0851] 31 shows an example in which the insertion position of phase shifter 205A is before weighting combiner 203 and the insertion position of phase shifter 205B is before weighting combiner 203 in the configuration of FIG.

[0852] Phase change section 205A receives mapped signal s1(t) 201A and control signal 200 as input, performs a phase change on mapped signal 201A based on control signal 200, and outputs phase-changed signal 2801A.

[0853] Phase change section 205A, for example, applies a phase change of w(i) to mapped signal s1(i). Therefore, phase-changed signal s1'(i) 2901A can be expressed as s1'(i)=w(i)×s1(i), where i is the symbol number and is an integer equal to or greater than 0. Note that w(i) is given as explained in the first embodiment.

[0854] Phase change section 205B, for example, applies a phase change of y(i) to s2(i). Therefore, signal s2'(i) 2801B after phase change can be expressed as s2'(i)=y(i)×s2(i), where i is the symbol number and is an integer equal to or greater than 0. Note that the method of giving y(i) is as explained in the first embodiment.

[0855] Weighting combination section 203 receives phase-changed signal s1'(i) 2801A, phase-changed signal s2'(i) 2801B, and control signal 200 as input, performs weighting combination (precoding) based on control signal 200, and outputs weighted combined signal 204A and weighted combined signal 204B. Specifically, a vector formed by phase-changed signal s1'(i) 2801A and phase-changed signal s2'(i) 2801B is multiplied by a precoding matrix to obtain weighted combined signal 204A and weighted combined signal 204B. Note that an example of the configuration of the precoding matrix is ​​as described in embodiment 1. The following description is the same as that in FIG. 20, and therefore will not be repeated.

[0856] Fig. 32 shows an example in which, compared to the configuration in Fig. 21, the insertion position of phase modification section 205A is before weighting combination section 203, and the insertion position of phase modification section 205B is before weighting combination section 203. In this case, the operations of phase modification section 205A, phase modification section 205B, and weighting combination section 203 have been explained in the explanation of Fig. 31, so explanations thereof will be omitted. Furthermore, the operations of weighting combination section 203 and subsequent sections are the same as those explained in Fig. 21, so explanations thereof will be omitted.

[0857] Fig. 33 shows an example in which, compared to the configuration in Fig. 22, the insertion position of phase modification section 205A is before weighting combination section 203, and the insertion position of phase modification section 205B is before weighting combination section 203. In this case, the operations of phase modification section 205A, phase modification section 205B, and weighting combination section 203 have been explained in the explanation of Fig. 31, so explanation thereof will be omitted. Furthermore, the operations after weighting combination section 203 are the same as those explained in Fig. 22, so explanation thereof will be omitted.

[0858] In FIG. 27, a terminal requests communication with a base station.

[0859] Then, the base station determines, for example, using random numbers, the phase change values ​​to be applied by the phase change unit 205A and / or the phase change unit 205B as "first specific phase change values ​​(set)." Then, the base station applies phase change in the phase change unit 205A and / or the phase change unit 205B based on the determined "first specific phase change values ​​(set)." At this time, the control information symbol 2701_1 includes information on the "first specific phase change values ​​(set)."

[0860] Note that the phrase "first specific phase change value (set)" has been used. In the cases of FIGS. 2, 18, 19, 28, 29, and 30, phase change unit 205A does not exist, but phase change unit 205B does. Therefore, in these cases, it is necessary to prepare a first specific phase change value to be used in phase change unit 205B. On the other hand, in the cases of FIGS. 20, 21, 22, 31, 32, and 33, phase change unit 205A and phase change unit 205B exist. In these cases, it is necessary to prepare a first specific phase change value #A to be used in phase change unit 205A and a first specific phase change value #B to be used in phase change unit 205B. Accordingly, the phrase "first specific phase change value (set)" has been used.

[0861] The base station transmits a control information symbol 2701_1 and a data symbol #1 2702_1, and at least the phase of the data symbol #1 2702_1 is changed according to the determined "first specific phase change value (set)."

[0862] The terminal receives control information symbol 2701_1 and data symbol #1 2702_1 transmitted by the base station, and demodulates and decodes data symbol #1 2702_1 based on information of at least the "first specific phase change value (set)" included in control information symbol 2701_1. As a result, the terminal determines that "the data included in data symbol #1 2702_1 has been obtained without error." Then, the terminal transmits terminal transmission symbol 2750_1 to the base station, which includes at least information that "the data included in data symbol #1 2702_1 has been obtained without error."

[0863] The base station receives the terminal transmission symbol 2750_1 transmitted by the terminal, and based on the information contained in the terminal transmission symbol 2750_1 that at least "the data contained in the data symbol #1 2702_1 was obtained without error," determines that the phase change (set) to be performed by the phase change unit 205A and / or the phase change unit 205B will be a "first specific phase change value (set)," as when transmitting the data symbol #1 2702_1.

[0864] Because the base station has "obtained the data included in data symbol #1 2702_1 without error," it can determine that the terminal is likely to be able to obtain the data without error even if it uses the "first specific phase change value (set)" when transmitting the next data symbol. This provides the effect of ensuring that the terminal is likely to obtain high data reception quality.

[0865] Then, the base station performs phase modification in the phase modification unit 205A and / or the phase modification unit 205B based on the determined "first specific phase modification value (set)." At this time, the control information symbol 2701_2 includes information on the "first specific phase modification value (set)."

[0866] The base station transmits the control information symbol 2701_2 and the data symbol #2 2702_2, and at least the phase of the data symbol #2 2702_2 is changed according to the determined "first specific phase change value (set)."

[0867] ...

Claims

1. a signal processing circuit that generates a first control signal and a second control signal by performing a cyclic shift diversity method, and generates a first phase-shifted transmission signal sequence z1(i) and a second phase-shifted transmission signal sequence z2(i) by performing a first signal processing and a second signal processing, where i is a symbol number; a transmitter configured to transmit the first control signal and the phase-shifted first transmission signal sequence z1(i) and the second control signal and the phase-shifted second transmission signal sequence z2(i) via multiple antennas in a single carrier mode; the first signal processing performs phase modification on the plurality of data symbols of the first modulated signal sequence s1(i) and the plurality of data symbols of the second modulated signal sequence s2(i) in accordance with a first phase modification value that changes periodically with a period N, where N is an integer equal to or greater than 2, and the first phase modification value applied to the first modulated signal sequence s1(i) has the same absolute value but a different sign from the first phase modification value applied to the second modulated signal sequence s2(i); in the second signal processing, generating the first transmission signal sequence z1(i) and the second transmission signal sequence z2(i) from the phase-shifted first modulated signal sequence s1(i) and the phase-shifted second modulated signal sequence s2(i), and performing phase shifts on the first transmission signal sequence z1(i) and the second transmission signal sequence z2(i) in accordance with a second phase shift value that is constant over time and provided for each of the first transmission signal sequence z1(i) and the second transmission signal sequence z2(i); a second phase modification value applied to the first transmission signal sequence z1(i) is different from a second phase modification value applied to the second transmission signal sequence z2(i); Transmitting device.

2. The signal processing circuit inserts a plurality of pilot symbols into each of the phase-shifted first modulated signal sequence s1(i) and the phase-shifted second modulated signal sequence s2(i) after the first signal processing and before the second signal processing. The transmitting device according to claim 1 .

3. The first phase modification value y(i) applied to the first modulated signal sequence s1(i) is [Equation 1] It is expressed as The transmitting device according to claim 1 .

4. At least one of the second phase change values ​​provided for each of the first transmission signal sequence z1(i) and the second transmission signal sequence z2(i) is [Equation 2] is The transmitting device according to claim 1 .

5. A transmission method performed by a transmission device, comprising: generating a first control signal and a second control signal by performing a Cyclic Shift Diversity method, and a first phase-shifted transmission signal sequence z1(i) and a second phase-shifted transmission signal sequence z2(i) by performing first signal processing and second signal processing, where i is a symbol number; transmitting the first control signal and the phase-changed first transmission signal sequence z1(i) and the second control signal and the phase-changed second transmission signal sequence z2(i) via multiple antennas in a single carrier mode; the first signal processing performs phase modification on the plurality of data symbols of the first modulated signal sequence s1(i) and the plurality of data symbols of the second modulated signal sequence s2(i) in accordance with a first phase modification value that changes periodically with a period N, where N is an integer equal to or greater than 2, and the first phase modification value applied to the first modulated signal sequence s1(i) has the same absolute value but a different sign from the first phase modification value applied to the second modulated signal sequence s2(i); in the second signal processing, generating the first transmission signal sequence z1(i) and the second transmission signal sequence z2(i) from the phase-shifted first modulated signal sequence s1(i) and the phase-shifted second modulated signal sequence s2(i), and performing phase shifts on the first transmission signal sequence z1(i) and the second transmission signal sequence z2(i) in accordance with a second phase shift value that is constant over time and provided for each of the first transmission signal sequence z1(i) and the second transmission signal sequence z2(i); a second phase modification value applied to the first transmission signal sequence z1(i) is different from a second phase modification value applied to the second transmission signal sequence z2(i); Sending method.

6. After the first signal processing and before the second signal processing, a plurality of pilot symbols are inserted into each of the phase-shifted first modulated signal sequence s1(i) and the phase-shifted second modulated signal sequence s2(i). The transmission method according to claim 5.

7. The first phase modification value y(i) applied to the first modulated signal sequence s1(i) is [Equation 3] It is expressed as The transmission method according to claim 5.

8. At least one of the second phase change values ​​provided for each of the first transmission signal sequence z1(i) and the second transmission signal sequence z2(i) is [Equation 4] is The transmission method according to claim 5.

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