Transmission device and transmission method

Abstract

To provide a transmission device for improving data reception quality.SOLUTION: A transmission device includes: a mapping unit; a signal processing unit; and a transmission unit. The mapping unit is configured to: when a first precoding is valid, generate a plurality of first symbols; and when the first precoding is not valid, generate a second symbol and a third symbol. The signal processing unit is configured to: when the first precoding is valid, perform the first precoding so as to generate a plurality of first precoded symbols; and when the first precoding is not valid, perform the second precoding so as to generate the second precoded symbol and the third precoded symbol. The transmission unit is configured to transmit the first precoded symbol or the second precoded symbol and the third precoded symbol. Therein the plurality of first precoded symbols is mapped respectively to a plurality of different subcarriers.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention 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.

[0003] 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 an encoding unit 002 is divided into data 005A and data 005B by a distributor 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.

[0004] 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. [Prior art documents] [Non-patent literature]

[0005] [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 [Problem to be solved by the invention]

[0006] The present invention relates to a transmission method for transmitting a single-stream signal and multiple-stream signals together when using a multi-carrier transmission method such as the OFDM method, thereby improving the reception quality of single-stream data and also improving the reception quality of multiple-stream data in a propagation environment including LOS (line-of-sight). [Means for solving the problem]

[0007] A transmitting device according to the present invention includes a mapping unit, a signal processing unit, and a transmitting unit, wherein the mapping unit, in operation, generates a plurality of first symbols by modulating a bit sequence when first precoding is enabled, and generates a second symbol and a third symbol by modulating the bit sequence when the first precoding is not enabled, and the signal processing unit, in operation, performs the first precoding on the plurality of first symbols when the first precoding is enabled, to generate a plurality of first precoded symbols, each of which is a weighted addition of the plurality of first symbols, and When precoding is not enabled, a second precoding is performed on the second symbol and the third symbol to generate a second precoded symbol that is a weighted addition of the second symbol and the third symbol, and a third precoded symbol that is a weighted addition of the second symbol and the third symbol, and the transmitter unit transmits the first precoded symbol or the second precoded symbol and the third precoded symbol in operation, and each of the multiple first precoded symbols is mapped to a multiple subcarrier that is different from each other.

[0008] A transmission method according to the present invention is a transmission method performed by a transmitting device, and includes a first step of generating a plurality of first symbols by modulating a bit sequence when first precoding is enabled, and generating second symbols and third symbols by modulating a bit sequence when the first precoding is not enabled; a second step of generating a plurality of first precoded symbols, each of which is a weighted addition of the plurality of first symbols, by performing the first precoding on the plurality of first symbols when the first precoding is enabled, and generating a second precoded symbol, each of which is a weighted addition of the second symbol and the third symbol, by performing second precoding on the second symbol and the third symbol when the first precoding is not enabled; and a third step of transmitting the first precoded symbols or the second precoded symbols and the third precoded symbols.

[0009] A receiving device according to the present invention includes a receiving unit that receives a signal transmitted according to a predetermined transmission method, and a demodulating unit that demodulates the received signal, wherein the predetermined transmission method performs precoding processing on a first baseband signal and a second baseband signal to generate a first precoded signal and a second precoded signal, inserts a pilot signal into the first precoded signal, performs a phase change on the second precoded signal by i × Δλ, where i is an integer greater than or equal to 0, inserts a pilot signal into the second precoded signal after the phase change, and performs a phase change on the second precoded signal after the phase change and pilot signal insertion, wherein Δλ is a difference in the amount of phase change applied to two symbols having consecutive symbol numbers and satisfies π / 2 radians < Δλ < π radians or π radians < Δλ < 3π / 2 radians, and the demodulating unit performs demodulation processing in accordance with the phase change.

[0010] A receiving method according to the present invention receives a signal transmitted in accordance with a predetermined transmission method, in which the predetermined transmission method performs a precoding process on a first baseband signal and a second baseband signal to generate a first precoded signal and a second precoded signal, inserts a pilot signal into the first precoded signal, performs a phase shift on the second precoded signal by i × Δλ, where i is an integer greater than or equal to 0, inserts a pilot signal into the second precoded signal after the phase shift, and performs a phase shift on the second precoded signal after the phase shift and pilot signal insertion, where Δλ is a difference in the amount of phase shift applied to two symbols having consecutive symbol numbers and satisfies π / 2 radians < Δλ < π radians or π radians < Δλ < 3π / 2 radians, and demodulates the received signal by performing a demodulation process according to the phase shift. [Effects of the Invention]

[0011] Thus, according to the present invention, it is possible to improve the reception quality of single-stream data and also improve the reception quality of multiple-stream data in a propagation environment including LOS (line-of-sight), thereby making it possible to provide high-quality communication services. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a transmission device according to this embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of the signal processing unit in FIG. [Figure 3] FIG. 3 is a diagram illustrating an example of the configuration of the radio unit in FIG. [Figure 4] FIG. 4 is a diagram showing an example of a frame configuration of the transmission signal of FIG. [Figure 5] FIG. 5 is a diagram showing an example of a frame configuration of the transmission signal of FIG. [Figure 6] FIG. 6 is a diagram showing an example of the configuration of the portion related to the generation of control information in FIG. [Figure 7] FIG. 7 is a diagram illustrating an example of the configuration of the antenna unit in FIG. [Figure 8] FIG. 8 is a diagram showing an example of the configuration of a receiving device according to this embodiment. [Figure 9] FIG. 9 is a diagram showing the relationship between a transmitting device and a receiving device. [Figure 10] FIG. 10 is a diagram showing an example of the configuration of the antenna unit of FIG. [Figure 11] FIG. 11 is a diagram showing a part of the frame in FIG. [Figure 12] FIG. 12 is a diagram illustrating an example of a modulation method used in the mapping unit of FIG. [Figure 13] FIG. 13 is a diagram showing an example of a frame configuration of the transmission signal of FIG. [Figure 14] FIG. 14 is a diagram showing an example of a frame configuration of the transmission signal of FIG. [Figure 15]FIG. 15 is a diagram showing an example of a configuration when a CCD is used. [Figure 16] FIG. 16 is a diagram showing an example of carrier allocation when OFDM is used. [Figure 17] FIG. 17 is a diagram showing an example of the configuration of a transmitting device based on the DVB-NGH standard. [Figure 18] FIG. 18 is a diagram illustrating an example of the configuration of the signal processing unit in FIG. [Figure 19] FIG. 19 is a diagram illustrating an example of the configuration of the signal processing unit in FIG. [Figure 20] FIG. 20 is a diagram illustrating an example of the configuration of the signal processing unit in FIG. [Figure 21] FIG. 21 is a diagram illustrating an example of the configuration of the signal processing unit in FIG. [Figure 22] FIG. 22 is a diagram illustrating an example of the configuration of the signal processing unit in FIG. [Figure 23] FIG. 23 is a diagram illustrating an example of the configuration of a base station. [Figure 24] FIG. 24 is a diagram illustrating an example of the configuration of a terminal. [Figure 25] FIG. 25 is a diagram illustrating an example of a frame configuration of a modulated signal. [Figure 26] FIG. 26 is a diagram illustrating an example of communication between a base station and a terminal. [Figure 27] FIG. 27 is a diagram illustrating an example of communication between a base station and a terminal. [Figure 28] FIG. 28 is a diagram illustrating an example of the configuration of the signal processing unit in FIG. [Figure 29] FIG. 29 is a diagram illustrating an example of the configuration of the signal processing unit in FIG. [Figure 30] FIG. 30 is a diagram illustrating an example of the configuration of the signal processing unit in FIG. [Figure 31] FIG. 31 is a diagram illustrating an example of the configuration of the signal processing unit in FIG. [Figure 32] FIG. 32 is a diagram illustrating an example of the configuration of the signal processing unit in FIG. [Figure 33] FIG. 33 is a diagram illustrating an example of the configuration of the signal processing unit in FIG. [Figure 34]FIG. 34 is a diagram showing an example of a system configuration in a state where a base station and a terminal are communicating with each other. [Figure 35] FIG. 35 is a diagram showing an example of communication between a base station and a terminal. [Figure 36] FIG. 36 is a diagram showing an example of data included in a reception capability notification symbol transmitted by the terminal of FIG. [Figure 37] FIG. 37 is a diagram showing an example of data included in a reception capability notification symbol transmitted by the terminal of FIG. [Figure 38] FIG. 38 is a diagram showing an example of data included in a reception capability notification symbol transmitted by the terminal of FIG. [Figure 39] FIG. 39 is a diagram illustrating an example of a frame configuration of the transmission signal in FIG. [Figure 40] FIG. 40 is a diagram illustrating an example of a frame configuration of the transmission signal in FIG. [Figure 41] FIG. 41 is a diagram showing an example of the configuration of a receiving device of the terminal in FIG. [Figure 42] FIG. 42 is a diagram showing an example of a frame configuration when a base station or AP uses a multicarrier transmission method to transmit a single modulated signal. [Figure 43] FIG. 43 is a diagram showing an example of a frame configuration when a base station or AP uses a single-carrier transmission method to transmit a single-modulated signal. [Figure 44] FIG. 44 is a diagram showing an example of the configuration of a transmitting device such as a base station, an access point, or a broadcasting station. [Figure 45] FIG. 45 is a diagram showing an example of a method for arranging symbols on the time axis of a signal. [Figure 46] FIG. 46 is a diagram showing an example of a method for arranging symbols on the frequency axis of a signal. [Figure 47] FIG. 47 is a diagram showing an example of symbol allocation on the time-frequency axis of a signal. [Figure 48] FIG. 48 is a diagram showing a second example of a symbol arrangement with respect to signal time. [Figure 49]FIG. 49 is a diagram showing a second example of an arrangement of symbols with respect to signal frequencies. [Figure 50] FIG. 50 is a diagram showing an example of symbol allocation with respect to time and frequency of a signal. [Figure 51] FIG. 51 is a diagram illustrating an example of the configuration of a modulated signal transmitted by a base station or an AP. [Figure 52] FIG. 52 is a diagram showing an example of a frame configuration during "single-stream modulated signal transmission 5101" in FIG. [Figure 53] FIG. 53 is a diagram showing an example of a frame configuration when "transmitting multiple modulated signals for multiple streams 5102" in FIG. [Figure 54] FIG. 54 is a diagram illustrating an example of the configuration of a signal processing unit in a transmission device of a base station. [Figure 55] FIG. 55 is a diagram illustrating an example of the configuration of a radio unit. [Figure 56] FIG. 56 is a diagram illustrating an example of the configuration of a signal processing unit in a transmission device of a base station. [Figure 57] FIG. 57 is a diagram illustrating an example of the configuration of a modulated signal transmitted by a base station or an AP. [Figure 58] FIG. 58 is a diagram showing an example of a frame configuration when "single-stream modulated signal transmission 5701" in FIG. [Figure 59] FIG. 59 is a diagram showing a first example in which phase change units are arranged before and after a weighting synthesis unit. [Figure 60] FIG. 60 is a diagram showing a second example in which phase change units are arranged before and after the weighting synthesis unit. [Figure 61] FIG. 61 is a diagram showing a third example in which phase change units are arranged before and after a weighting synthesis unit. [Figure 62] FIG. 62 is a diagram showing a fourth example in which phase change units are arranged before and after a weighting synthesis unit. [Figure 63] FIG. 63 is a diagram showing a fifth example in which phase change units are arranged before and after a weighting synthesis unit. [Figure 64]FIG. 64 is a diagram showing a sixth example in which phase change units are arranged before and after a weighting synthesis unit. [Figure 65] FIG. 65 is a diagram showing a seventh example in which phase change units are arranged before and after the weighting synthesis unit. [Figure 66] FIG. 66 is a diagram showing an eighth example in which phase change units are arranged before and after the weighting synthesis unit. [Figure 67] FIG. 67 is a diagram showing a ninth example in which phase change units are arranged before and after the weighting synthesis unit. [Figure 68] FIG. 68 is a diagram for explaining the operation of the mapping unit in FIG. [Figure 69] FIG. 69 is a diagram illustrating an example of a signal point arrangement in the in-phase I-quadrature Q plane for QPSK. [Figure 70] FIG. 70 is a diagram showing an example of a signal point arrangement in the in-phase I-quadrature Q plane for QPSK. [Figure 71] FIG. 71 is a diagram illustrating an example of a signal point arrangement in the in-phase I-quadrature Q plane for QPSK. [Figure 72] FIG. 72 is a diagram illustrating an example of a signal point arrangement in the in-phase I-quadrature Q plane for QPSK. [Figure 73] FIG. 73 is a diagram illustrating an example of the configuration of a transmitting device of a base station or AP. [Figure 74] FIG. 74 is a diagram for explaining the operation of the mapping unit in FIG. [Figure 75] FIG. 75 is a diagram for explaining the operation of the mapping unit in FIG. [Figure 76] FIG. 76 is a diagram for explaining the operation of the mapping unit in FIG. [Figure 77] FIG. 77 is a diagram for explaining the operation of the mapping unit in FIG. [Figure 78] FIG. 78 is a diagram for explaining the operation of the mapping unit in FIG. [Figure 79] FIG. 79 is a diagram showing an example of data included in the "receiving capability notification symbol" transmitted by the terminal in FIG. [Figure 80]FIG. 80 is a diagram showing an example of a frame configuration. [Figure 81] FIG. 81 is a diagram showing an example of a frame configuration of the transmission signal of FIG. [Figure 82] FIG. 82 is a diagram showing an example of a frame configuration of the transmission signal of FIG. [Figure 83] FIG. 83 is a diagram showing the spectrum of the transmission signal of FIG. [Figure 84] FIG. 84 is a diagram showing a signal point arrangement on the in-phase I-quadrature Q plane in the case of BPSK. [Figure 85] FIG. 85 is a diagram showing a signal point arrangement when the symbol number i is an even number. [Figure 86] FIG. 86 is a diagram showing signal points of a pre-coded signal on the in-phase I-quadrature Q plane in the case of BPSK. [Figure 87] FIG. 87 is a diagram showing signal points on the in-phase I-quadrature Q plane of the signal after weighting and combining. [Figure 88] FIG. 88 is a diagram showing an example of a frame configuration of a transmission signal transmitted by a base station or AP. [Figure 89] FIG. 89 is a diagram illustrating an example of the configuration of a receiving device. [Figure 90] FIG. 90 is a diagram illustrating an example of the configuration of a transmitting device. [Figure 91] FIG. 91 is a diagram showing an example of the configuration of the signal processing unit in FIG. 90. In FIG. [Figure 92] FIG. 92 is a diagram showing an example of a frame structure of a modulated signal transmitted by the transmitting device of FIG. [Figure 93] FIG. 93 is a diagram showing an example of a frame structure of a modulated signal transmitted by the transmitting device of FIG. [Figure 94] FIG. 94 is a diagram showing a specific example of the configuration of the reception capability notification symbol transmitted by the terminal shown in FIG. [Figure 95] FIG. 95 is a diagram showing an example of the configuration of the "reception capability notification symbol related to the single carrier method and the OFDM method" shown in FIG. [Figure 96]FIG. 96 is a diagram showing an example of the configuration of the "reception capability notification symbol related to the single carrier system" shown in FIG. [Figure 97] FIG. 97 is a diagram showing an example of the configuration of the "receiving capability notification symbol for the OFDM method" shown in FIG. [Figure 98] FIG. 98 is a diagram showing a specific example of the configuration of the reception capability notification symbol transmitted by the terminal shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0014] (Embodiment 1) The transmission method, transmission device, reception method, and reception device of this embodiment will be described in detail.

[0015] 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.

[0016] 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 mapped signal (baseband signal) 105_1 and mapped signal (baseband signal) 105_2. 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, it is assumed that the first sequence and the second sequence are different.

[0017] 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. In this case, 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). The signal processing will be described later with reference to FIG. 2.

[0018] 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).

[0019] Similarly, radio section 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 section #B (109_B).

[0020] Antenna unit #A (109_A) receives control signal 100 as input. At this time, it processes transmission signal 108_A based on control signal 100 and outputs it as radio waves. However, antenna unit #A (109_A) does not necessarily receive control signal 100 as input.

[0021] Similarly, antenna unit #B (109_B) receives control signal 100 as input. At this time, 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.

[0022] The control signal 100 may be generated based on information transmitted by the device in FIG. 1 that is the communication partner, or may be generated based on information input from an input unit provided in the device in FIG. 1.

[0023] 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 (corresponding to mapped signal 105_1 in FIG. 1), mapped signal 201B (corresponding to mapped signal 105_2 in FIG. 1), and control signal 200 (corresponding to 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 is, for example, time. (s1(t), s2(t), z1(t), and z2'(t) are defined as complex numbers (and therefore may be real numbers).)

[0024] The weighting synthesis unit (precoding unit) 203 performs the following calculation.

[0025]

number

[0026] In equation (1), a, b, c, and d can be defined as complex numbers, and therefore a, b, c, and d are defined as complex numbers (they may also be real numbers). Note that i is a symbol number.

[0027] Phase shifter 205B receives weighted and combined signal 204B and control signal 200 as input, performs a phase shift on weighted and combined signal 204B based on control signal 200, and outputs phase-shifted signal 206B. Phase-shifted signal 206B is represented by z2(t), which is defined as a complex number (or may be a real number).

[0028] 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). (i is the symbol number (i is an integer equal to or greater than 0))

[0029] For example, the phase change value is set as follows: (N is an integer of 2 or more, and N is the phase change period.) (Setting N to an odd number of 3 or more may improve data reception quality.)

[0030]

number

[0031] In this case, z1(i) and z2(i) can be expressed by the following equations:

[0032]

number

[0033] 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).

[0034] 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.

[0035] (Precoding) matrices in equations (1) and (3)

number

[0036]

number

number

number

number

number

number

number

number

[0037] 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). or

number

number

number

number

number

number

number

number

[0038] 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.) or

number

number

number

number

number

number

number

number

number

number

number

number

[0039] However, θ 11 (i), θ 21 (i), λ(i) is a function of i (symbol number) (real number), λ is, for example, a fixed value (real number) (it does not have to be a fixed value), 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). Also, θ 11 , θ 21 is a real number.

[0040] Furthermore, the embodiments of this specification can be implemented using precoding matrices other than these. or

number

number

number

number

[0041] In addition, β in equations (34) and (36) may be a real number or an imaginary number, but β is not 0 (zero).

[0042] Insertion section 207A receives weighted combined signal 204A, pilot symbol signal (pa(t)) (t: time) (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.

[0043] Similarly, insertion unit 207B receives phase-changed 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 information on the frame configuration included in control signal 200.

[0044] 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) × x'(i) (j is the imaginary unit).

[0045] As will be described later, the operation of phase changer 209B may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209B is characterized in that it performs phase change on symbols present in the frequency axis direction (applying phase change to data symbols, pilot symbols, control information symbols, etc.).

[0046] 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 (corresponding to control signal 100 in Fig. 1), performs serial-to-parallel conversion based on control signal 300, and outputs signal 303 after serial-to-parallel conversion.

[0047] The inverse Fourier transform unit 304 receives the serial-to-parallel converted signal 303 and the control signal 300 as input, performs an inverse Fourier transform (e.g., an inverse fast Fourier transform (IFFT)) based on the control signal 300, and outputs a post-inverse Fourier transform signal 305.

[0048] 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 .

[0049] (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.)

[0050] FIG. 4 shows the frame structure of 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 from carrier 1 to carrier 36. FIG. 4 also shows symbols from time $1 to time $11.

[0051] In Fig. 4, 401 indicates a pilot symbol (corresponding to pilot signal 251A (pa(t)) in Fig. 2), 402 indicates a data symbol, and 403 indicates other symbols. In this case, the pilot symbol is, for example, a PSK (Phase Shift Keying) symbol, and is a symbol used by a receiving device receiving this frame to perform channel estimation (estimation of propagation path fluctuations) and estimation of frequency offset and phase fluctuations. For example, it is preferable that the transmitting device in Fig. 1 and the receiving device receiving the frame in Fig. 4 share the same method of transmitting pilot symbols.

[0052] 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.

[0053] Data symbol 402 is a symbol corresponding to baseband signal 208A generated by signal processing according to FIG. 2, and therefore 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 weighting and combining unit 203.

[0054] The other symbols 403 are assumed to be 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 control information symbols.) In this case, the preamble may transmit data (for control purposes) 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.

[0055] 4, carriers 1 through 36 from time $1 through time $4 become other symbols 403. Then, carriers 1 through 11 at time $5 become data symbols 402. Thereafter, carrier 12 at time $5 becomes pilot symbol 401, carriers 13 through 23 at time $5 become data symbols 402, carrier 24 at time $5 becomes pilot symbol 401, ..., carriers 1 through 2 at time $6 become data symbols 402, carrier 3 at time $6 becomes pilot symbol 401, ..., carrier 30 at time $11 becomes pilot symbol 401, and carriers 31 through 36 at time $11 become data symbols 402.

[0056] 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 from carrier 1 to carrier 36. FIG. 5 also shows symbols from time $1 to time $11.

[0057] In Fig. 5, 501 indicates a pilot symbol (corresponding to pilot signal 251B (pb(t)) in Fig. 2), 502 indicates a data symbol, and 503 indicates other symbols. In this case, the pilot symbol is, for example, a PSK symbol, and is a symbol used by a receiving device receiving this frame to perform channel estimation (estimation of propagation path fluctuations) and estimation of frequency offset and phase fluctuations. For example, it is preferable that the transmitting device in Fig. 1 and the receiving device receiving the frame in Fig. 5 share the same method of transmitting pilot symbols.

[0058] 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.

[0059] The other symbols 503 are assumed to be symbols corresponding to the preamble signal 252 and the 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 control purposes) 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. 5 to demodulate and decode the data symbols.

[0060] 5, carriers 1 through 36 from time $1 through time $4 become other symbols 403. Then, carriers 1 through 11 at time $5 become data symbols 402. Thereafter, carrier 12 at time $5 becomes pilot symbol 401, carriers 13 through 23 at time $5 become data symbols 402, carrier 24 at time $5 becomes pilot symbol 401, ..., carriers 1 through 2 at time $6 become data symbols 402, carrier 3 at time $6 becomes pilot symbol 401, ..., carrier 30 at time $11 becomes pilot symbol 401, and carriers 31 through 36 at time $11 become data symbols 402.

[0061] 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 will be 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.

[0062] The other symbols in Figures 4 and 5 are symbols corresponding to "preamble signal 252 and control information symbol signal 253 in Figure 2." Therefore, if other symbols 503 in Figure 5, which are transmitted at the same time and on the same frequency (same carrier) as other symbols 403 in Figure 4, are transmitting control information, they are transmitting the same data (same control information).

[0063] It is assumed that the receiving device will receive the frames of Figures 4 and 5 simultaneously, but it is possible for the receiving device to obtain the data transmitted by the transmitting device even if it receives only the frame of Figure 4 or only the frame of Figure 5.

[0064] 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.

[0065] 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 .

[0066] FIG. 7 shows an example of the configuration of antenna unit #A (109_A) and antenna unit #B (109_B) in FIG. 1. (This is an example in which antenna unit #A (109_A) and antenna unit #B (109_B) are configured with multiple antennas.)

[0067] The distributor 702 receives the transmission signal 701, distributes it, and outputs transmission signals 703_1, 703_2, 703_3, and 703_4.

[0068] 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.

[0069] If the transmitted signal 703_1 is Tx1(t) (t: time) and the multiplication coefficient is W1 (W1 can be defined as a complex number and therefore may be a real number), the signal 705_1 after multiplication is expressed as Tx1(t) × W1.

[0070] 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.

[0071] If the transmit signal 703_2 is Tx2(t) and the multiplication coefficient is W2 (W2 can be defined as a complex number and therefore may be a real number), the signal 705_2 after multiplication is expressed as Tx2(t)×W2.

[0072] 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.

[0073] If the transmit signal 703_3 is Tx3(t) and the multiplication coefficient is W3 (W3 can be defined as a complex number and therefore may be a real number), the signal 705_3 after multiplication is expressed as Tx3(t)×W3.

[0074] 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.

[0075] If the transmit signal 703_4 is Tx4(t) and the multiplication coefficient is W4 (W4 can be defined as a complex number and therefore may be a real number), the signal 705_4 after multiplication is expressed as Tx4(t)×W4.

[0076] It should be noted that the absolute values of W1, W2, W3, and W4 may be equal. This is equivalent to a phase change. (Naturally, the absolute values of W1, W2, W3, and W4 do not have to be equal.)

[0077] Also, in Figure 7, an example is described in which the antenna unit is composed of four antennas (and four multiplication units), but the number of antennas is not limited to four, and it may be composed of two or more antennas.

[0078] When the configuration of antenna unit #A (109_A) in Fig. 1 is as shown in Fig. 7, transmission signal 701 corresponds to transmission signal 108_A in Fig. 1. When the configuration of antenna unit #B (109_B) in Fig. 1 is as 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 have to receive control signal 100 as an input.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 8 shows antenna unit #X (801X) and antenna unit #Y (801Y) configured to receive control signal 810 as an input, they may also be configured not to receive control signal 810. The operation when control signal 810 is present as an input will be described in detail later.

[0083] Incidentally, the relationship between the transmitting device and the 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087]

number

[0088] Note that n1(i) and n2(i) are noise.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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 the received data 812.

[0095] 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.

[0096] Fig. 10 shows an example of the configuration of antenna unit #X (801X) and antenna unit #Y (801Y) in Fig. 8. (This is an example in which antenna unit #X (801X) and antenna unit #Y (801Y) are configured with multiple antennas.)

[0097] 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.

[0098] If the received signal 1002_1 is Rx1(t) (t: time) and the multiplication coefficient is D1 (D1 can be defined as a complex number and therefore may be a real number), the signal 1004_1 after multiplication is expressed as Rx1(t) × D1.

[0099] 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.

[0100] If the received signal 1002_2 is Rx2(t) and the multiplication coefficient is D2 (D2 can be defined as a complex number and therefore may be a real number), the signal 1004_2 after multiplication is expressed as Rx2(t)×D2.

[0101] 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.

[0102] If the received signal 1002_3 is Rx3(t) and the multiplication coefficient is D3 (D3 can be defined as a complex number and therefore may be a real number), the signal 1004_3 after multiplication is expressed as Rx3(t)×D3.

[0103] 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.

[0104] If the received signal 1002_4 is Rx4(t) and the multiplication coefficient is D4 (D4 can be defined as a complex number and therefore may be a real number), the signal 1004_4 after multiplication is expressed as Rx4(t)×D4.

[0105] 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.

[0106] In FIG. 10, an example is described in which the antenna unit is configured with four antennas (and four multiplication units), but the number of antennas is not limited to four, and it may be configured with two or more antennas.

[0107] When the configuration of antenna unit #X (801X) in Fig. 8 is as shown in Fig. 10, received signal 802X corresponds to composite signal 1006 in Fig. 10, and control signal 710 corresponds to control signal 1000 in Fig. 10. When the configuration of antenna unit #Y (801Y) in Fig. 8 is as shown in Fig. 10, received signal 802Y corresponds to composite 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 be configured as shown in Fig. 10, and as described above, the antenna unit does not have to receive control signal 710 as an input.

[0108] 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.

[0109] 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.

[0110] As explained using Figures 4 and 5, phase change section 205B performs precoding (weighted combining) on mapped signal s1(i) (201A) (where i is a symbol number and is an integer equal to or greater than 0) obtained by mapping using a first sequence and mapped signal s2(i) (201B) obtained by mapping using a second sequence, and then performs a phase change on one of the resulting weighted combined signals 204A, 204B. Then, weighted combined signal 204A and 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 performed on data symbol 502 in Figure 5. (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.)

[0111] For example, Figure 11 shows carrier 1 to carrier 5 and time $4 to time $6 extracted from the frame in Figure 5. As in Figure 5, 501 is a pilot symbol, 502 is a data symbol, and 503 is other symbols.

[0112] As described above, in the symbols shown in FIG. 11, phase change unit 205B applies phase change to the (carrier 1, time $5) data symbol, (carrier 2, time $5) data symbol, (carrier 3, time $5) data symbol, (carrier 4, time $5) data symbol, (carrier 5, time $5) data symbol, (carrier 1, time $6) data symbol, (carrier 2, time $6) data symbol, (carrier 4, time $6) data symbol, and (carrier 5, time $6) data symbol.

[0113] Therefore, in the symbols shown in FIG. 11, the phase change value of the data symbol (carrier 1, time $5) is set as "e j×δ15(i) " and the phase change value of the data symbol (carrier 2, time $5) is "e j×δ25(i) " and the phase change value of the data symbol (carrier 3, time $5) is "e j×δ35(i) " and the phase change value of the data symbol (carrier 4, time $5) is "e j×δ45(i) " and the phase change value of the data symbol (carrier 5, time $5) is "e j×δ55(i) " and the phase change value of the data symbol (carrier 1, time $6) is "e j×δ16(i) " and the phase change value of the data symbol (carrier 2, time $6) is "e j×δ26(i) " and the phase change value of the data symbol (carrier 4, time $6) is "e j×δ46(i) " and the phase change value of the data symbol (carrier 5, time $6) is "e j×δ56(i) "

[0114] On the other hand, in the symbols shown in Figure 11, other symbols of (carrier 1, time $4), other symbols of (carrier 2, time $4), other symbols of (carrier 3, time $4), other symbols of (carrier 4, time $4), other symbols of (carrier 5, time $4), and pilot symbols of (carrier 3, time $6) are not subject to phase modification by phase modification unit 205B.

[0115] This is a characteristic feature of phase changer 205B. Note that, as shown in Fig. 4, data carriers are arranged at the "same carrier, same time" as the (carrier 1, time $5) data symbol, (carrier 2, time $5) data symbol, (carrier 3, time $5) data symbol, (carrier 4, time $5) data symbol, (carrier 5, time $5) data symbol, (carrier 1, time $6) data symbol, (carrier 2, time $6) data symbol, (carrier 4, time $6) data symbol, and (carrier 5, time $6) data symbol, which are the targets of phase change in Fig. 11. 4, (carrier 1, time $5) is a data symbol, (carrier 2, time $5) is a data symbol, (carrier 3, time $5) is a data symbol, (carrier 4, time $5) is a data symbol, (carrier 5, time $5) is a data symbol, (carrier 1, time $6) is a data symbol, (carrier 2, time $6) is a data symbol, (carrier 4, time $6) is a data symbol, and (carrier 5, time $6) is a data symbol. (In other words, data symbols undergoing MIMO transmission (transmitting multiple streams) are the targets of phase modification by phase modification section 205B.)

[0116] An example of the phase change that phase change unit 205B applies to the data symbols is a method of performing regular phase change (phase change period N) on the data symbols as shown in equation (2). (However, the method of phase change applied to the data symbols is not limited to this.)

[0117] By doing so, in an environment where direct waves are dominant, particularly in an LOS environment, it is possible to obtain the effect of improving the reception quality of data at a receiving device for data symbols undergoing MIMO transmission (transmitting multiple streams). This effect will now be explained.

[0118] For example, assume that the modulation scheme used in mapping section 104 in FIG. 1 is QPSK (Quadrature Phase Shift Keying). (Mapped signal 201A in FIG. 2 is a QPSK signal, and mapped signal 201B is also a QPSK signal. In other words, two QPSK streams are transmitted.) Then, signal processing section 811 in FIG. 8 uses, for example, channel estimation signals 806_1 and 806_2 to obtain 16 candidate signal points. (QPSK can transmit 2 bits, and a total of 4 bits are transmitted using 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.)

[0119] An example of this state is shown in Figure 12. In both Figures 12(A) and 12(B), 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. (Of the 16 candidate signal points, one is the signal point transmitted by the transmitting device. For this reason, they are called "16 candidate signal points.")

[0120] In an environment where direct waves are dominant, especially in an LOS environment, First case: When the phase change unit 205B of FIG. 2 is not present (that is, when the phase change unit 205B of FIG. 2 does not perform phase change) Think about it.

[0121] In the "first case," no phase change is performed, which may result in a state like that shown in (A) of Fig. 12. If the state shown in (A) of Fig. 12 occurs, there will be areas where signal points are dense (signal points are close together), such as "signal points 1201 and 1202," "signal points 1203, 1204, 1205, 1206," and "signal points 1207, 1208," which may result in a decrease in data reception quality in the receiving device of Fig. 8.

[0122] To overcome this problem, phase shifter 205B is inserted in Fig. 2. When phase shifter 205B is inserted, the symbol number i will contain a mixture of symbol numbers where signal points are dense (the distance between signal points is short) as shown in Fig. 12(A) and symbol numbers where the distance between signal points is long as shown in Fig. 12(B). In this situation, error correction coding is introduced, which makes it possible to obtain high error correction capability and to obtain high data reception quality in the receiving device of Fig. 8.

[0123] 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, in the data symbols, "a mixture of symbol numbers where, depending on symbol number i, there are parts where signal points are dense (the distance between signal points is short) as in Fig. 12(A) and symbol numbers where "the distance between signal points is long" as in Fig. 12(B)."

[0124] However, even if the phase shifter 205B in FIG. 2 shifts the phase of the pilot symbols and preambles used for channel estimation to demodulate (detect) data symbols, there may be cases where the data symbols include a mixture of symbol numbers with dense signal points (close distances between signal points) as shown in FIG. 12(A) and symbol numbers with long distances between signal points as shown in FIG. 12(B). In this case, some conditions must be imposed on the pilot symbols and preambles to shift the phase. For example, a method can be considered in which a different rule is established from the rule for shifting the phase of data symbols to shift the phase of pilot symbols and / or preambles. For example, a method can be used in which the phase of data symbols is shifted regularly with a period N, and the phase of pilot symbols and / or preambles is shifted regularly with a period M (N and M are integers equal to or greater than 2).

[0125] 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 (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)×x'(i) (j is the imaginary unit). The operation of phase changer 209B may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) as described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209B is characterized in that it performs phase change on symbols present in the frequency axis direction (it 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.)). (In the case of FIG. 2, phase changer 209B performs phase change on baseband signal 208B, and therefore performs phase change on each symbol shown in FIG. 5. When performing phase change on baseband signal 208A in FIG. 2, it performs phase change on each symbol shown in FIG. 4. This point will be explained later.)

[0126] Therefore, in the frame of FIG. 5, phase change section 209B of FIG. 2 applies phase change to all symbols from carrier 1 to carrier 36 at time $1 (in this case, all are other symbols 503).

[0127] Similarly, "Phase change unit 209B in FIG. 2 applies phase change to all symbols from carrier 1 to carrier 36 at time $2 (in this case, all are other symbols 503)." "Phase change unit 209B in FIG. 2 applies phase change to all symbols from carrier 1 to carrier 36 at time $3 (in this case, all are other symbols 503)." "Phase change unit 209B in FIG. 2 applies phase change to all symbols from carrier 1 to carrier 36 at time $4 (in this case, all are other symbols 503)." "Phase change unit 209B in FIG. 2 performs a phase change on all symbols from carrier 1 to carrier 36 at time $5 (in this case, pilot symbol 501 or data symbol 502)." "Phase change unit 209B in FIG. 2 performs a phase change on all symbols from carrier 1 to carrier 36 at time $6 (in this case, pilot symbol 501 or data symbol 502)." "Phase change unit 209B in FIG. 2 performs phase change on all symbols from carrier 1 to carrier 36 at time $7 (in this case, pilot symbol 501 or data symbol 502)." "Phase change unit 209B in FIG. 2 performs phase change on all symbols from carrier 1 to carrier 36 at time $8 (in this case, pilot symbol 501 or data symbol 502)." "Phase change unit 209B in FIG. 2 performs phase change on all symbols from carrier 1 to carrier 36 at time $9 (in this case, pilot symbol 501 or data symbol 502)." "Phase change unit 209B in FIG. 2 performs phase change on all symbols from carrier 1 to carrier 36 at time $10 (in this case, pilot symbol 501 or data symbol 502)." "Phase change unit 209B in FIG. 2 performs phase change on all symbols from carrier 1 to carrier 36 at time $11 (in this case, pilot symbol 501 or data symbol 502)." ...

[0128] FIG. 13 shows a frame configuration different from that of FIG. 4 of transmission signal 108_A of FIG. 1. In FIG. 13, components that operate in the same way as in FIG. 4 are assigned 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 from carrier 1 to carrier 36. As in FIG. 4, FIG. 13 shows symbols from time $1 to time $11.

[0129] In FIG. 13, in addition to pilot symbols 401 (corresponding to pilot signal 251A (pa(t)) in FIG. 2), data symbols 402, and other symbols 403, null symbols 1301 are inserted.

[0130] 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.)

[0131] In FIG. 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. For example, null symbols may be inserted at a specific time, at a specific frequency and time domain, continuously in the time-frequency domain, or discretely in the time-frequency domain.)

[0132] 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 from carrier 1 to carrier 36. As in FIG. 5, FIG. 14 shows symbols from time $1 to time $11.

[0133] In FIG. 14, in addition to pilot symbols 501 (corresponding to pilot signal 251B (pb(t)) in FIG. 2), data symbols 502, and other symbols 503, null symbols 1301 are inserted.

[0134] 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.)

[0135] In FIG. 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. For example, null symbols may be inserted at a specific time, at a specific frequency and time domain, continuously in the time-frequency domain, or discretely in the time-frequency domain.)

[0136] 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 will be transmitted at the same time and on the same frequency. Note that the frame structures in Figures 13 and 14 are merely examples.

[0137] 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).

[0138] It is assumed that the receiving device will receive the frames of Figures 13 and 14 simultaneously, but it is possible for the receiving device to obtain the data transmitted by the transmitting device even if it receives only the frame of Figure 13 or only the frame of Figure 14.

[0139] 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) ×x′(i) (j is an imaginary unit). The operation of the phase changer 209B may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Documents 2 and 3. Phase modification unit 209B is characterized in that it performs a phase modification on symbols existing in the frequency axis direction (phase modifications are performed on data symbols, pilot symbols, control information symbols, etc. At this time, null symbols can also be considered to be targets of phase modification. (Accordingly, in this case, the symbols targeted by symbol number i are data symbols, pilot symbols, control information symbols, preambles (other symbols), null symbols, etc.). However, even if a phase modification is performed on a null symbol, the signal before and after the phase modification are the same (the in-phase component I is zero (0), and the quadrature component Q is zero (0)). Therefore, it is also possible to interpret null symbols as not being targets of phase modification. (In the case of FIG. 2, phase modification unit 209B performs a phase modification on baseband signal 208B, and therefore performs a phase modification on each symbol shown in FIG. 14. When a phase modification is performed on baseband signal 208A in FIG. 2, a phase modification is performed on each symbol shown in FIG. 13. This point will be explained later.)

[0140] 14, phase change unit 209B in FIG. 2 applies phase change to all symbols from carrier 1 to carrier 36 at time $1 (in this case, all are other symbols 503). However, the handling of phase change for null symbol 1301 is as explained above.

[0141] Similarly, "For all symbols from carrier 1 to carrier 36 at time $2 (in this case, all are other symbols 503), phase change unit 209B in FIG. 2 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $3 (in this case, all are other symbols 503), phase change unit 209B in FIG. 2 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $4 (in this case, all are other symbols 503), phase change unit 209B in FIG. 2 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $5 (in this case, pilot symbol 501 or data symbol 502), phase change unit 209B in FIG. 2 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $6 (in this case, pilot symbol 501 or data symbol 502), phase change unit 209B in FIG. 2 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $7 (in this case, pilot symbol 501 or data symbol 502), phase change unit 209B in FIG. 2 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $8 (in this case, pilot symbol 501 or data symbol 502), phase change unit 209B in FIG. 2 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $9 (in this case, pilot symbol 501 or data symbol 502), phase change unit 209B in FIG. 2 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $10 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 2 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $11 (in this case, pilot symbol 501 or data symbol 502), phase change unit 209B in FIG. 2 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." ...

[0142] 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.

[0143] For example, the phase change value is set as follows (Q is an integer equal to or greater than 2, and Q is the phase change period):

[0144]

number

[0145] For example, Ω(i) may be set to perform a phase change with a period Q.

[0146] 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.

number

number

number

number

[0147] The above is an example of the operation of the phase changer 209B in FIG.

[0148] The effects obtained by the phase changer 209B in FIG. 2 will be described.

[0149] It is assumed that the other symbols 403, 503 in the "frames of Figs. 4 and 5" or "frames of Figs. 13 and 14" contain control information symbols. As explained above, if the other symbols 503 in Fig. 5, which are transmitted at the same time and on the same frequency (same carrier) as the other symbols 403, transmit control information, they transmit the same data (same control information).

[0150] Now, consider the following case.

[0151] Case 2: The control information symbols are transmitted using either antenna unit #A (109_A) or antenna unit #B (109_B) in FIG.

[0152] When transmitting as in "Case 2," the number of antennas transmitting 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)."

[0153] Case 3: Control information symbols are transmitted using both antenna unit #A (109_A) and antenna unit #B (109_B) in Fig. 1. However, no phase change is performed in phase change unit 209B in Fig. 2.

[0154] 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 there is 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 poses a problem in that the receiving device in Figure 8 may experience a decrease in data reception quality.

[0155] To alleviate this problem, 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 will be 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 will be obtained, which will improve the data reception quality in the receiving device of Fig. 8.

[0156] For the above reasons, in FIG. 2, phase change section 209B is provided to change the phase.

[0157] 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 (symbols for estimating propagation path fluctuations) for demodulating and decoding 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.

[0158] 4 and 5 or the frames of FIGS. 13 and 14, multiple streams are transmitted (MIMO transmission is performed) using the same frequency (band) and the same time using data symbols 402 and data symbols 502. To demodulate these data symbols, other symbols 403 and other symbols 503 are used, including symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation (symbols for estimating propagation path fluctuations).

[0159] At this time, as mentioned above, the phases of "symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation (symbols for estimating propagation path fluctuations) included in other symbols 403 and other symbols 503" are changed by phase change unit 209B.

[0160] Under such circumstances, if this processing is not reflected on data symbol 402 and data symbol 502 (in 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 (symbols for estimating propagation path fluctuations) included in other symbols 403 and other symbols 503" have been changed by phase change unit 209B.)

[0161] However, as shown in FIG. 2, when phase change section 209B performs a phase change on data symbol 402 and data symbol 502 (on data symbol 502 in the above explanation), the receiving device has the advantage of being able to (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 (symbols for estimating propagation path fluctuation)."

[0162] In addition, as shown in FIG. 2, when phase change section 209B applies a phase change to data symbol 402 and data symbol 502 (in the above description, to 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.

[0163] 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.

[0164] 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, particularly 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.

[0165] 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, particularly 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.

[0166] 2 illustrates a configuration in which phase changer 209B is provided subsequent to inserter 207B and performs a phase change on baseband signal 208B, but a configuration for obtaining both the effects of the phase change by phase changer 205B and the effects of the phase change by phase changer 209B described above is not limited to the configuration shown in Fig. 2. For example, a modified configuration may be used in which phase changer 209B is removed from the configuration of Fig. 2, baseband signal 208B output from inserter 207B is used as processed signal 106_B, and phase changer 209A that performs the same operation as phase changer 209B is added subsequent to inserter 207A, and phase-changed signal 210A obtained by phase change of baseband signal 208A by phase changer 209A is used as processed signal 106_A. 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, particularly 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.

[0167] 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.

[0168] (Supplementary Note 1) In the first embodiment and the like, it has been stated that the operation of the "phase changer B" may be the CDD (CSD) described in Non-Patent Document 2 and Non-Patent Document 3. A supplementary explanation will be given on this point.

[0169] The configuration when CDD (CSD) is used is shown in Fig. 15. Reference numeral 1501 denotes a modulated signal when no cyclic delay is applied, and is represented as X[n].

[0170] 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.

[0171]

number

[0172] Note that δ1 is the amount of cyclic delay (δ1 is a real number), and X[n] is composed of N symbols (N is an integer of 2 or more), and therefore n is an integer of 0 or more and N-1 or less. ...

[0173] 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.

[0174]

number

[0175] It should be noted that ΔM is the amount of cyclic delay (ΔM is a real number), and X[n] is made up of N symbols (N is an integer of 2 or more), and therefore n is an integer of 0 or more and N-1 or less.

[0176] Therefore, cyclic delay unit 1502_i (i is an integer between 1 and M (M is an integer greater than or equal to 1)) 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.

[0177]

number

[0178] Here, δi is the amount of cyclic delay (δi is a real number), and X[n] is composed of N symbols (N is an integer of 2 or more), so n is an integer of 0 or more and N-1 or less.

[0179] Then, the cyclically delayed signal 1503_i is transmitted from antenna i. (Therefore, the cyclically delayed signals 1503_1, . . . , and the cyclically delayed signal 1503_M are transmitted from different antennas.)

[0180] In this way, a diversity effect can be obtained by using cyclic delay (particularly, the adverse effects of delayed waves can be reduced), and the receiving device can achieve the effect of improving the reception quality of data.

[0181] 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.

[0182] 2, a cyclic delay amount δ (δ is a real number) 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.

[0183]

number

[0184] It should be noted that Y[n] is made up of N symbols (N is an integer of 2 or more), and therefore n is an integer of 0 or more and N-1 or less.

[0185] Next, the relationship between the amount of cyclic delay and phase change will be described.

[0186] For example, consider the case where CDD (CSD) is applied to OFDM. It is assumed that carrier allocation when using OFDM is as shown in FIG.

[0187] 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 the following are "Carrier 2," "Carrier 3," "Carrier 4," etc.

[0188] For example, suppose that a cyclic delay amount τ is applied in phase changer 209B in Fig. 2. Then, the phase change value Ω[i] for "carrier i" is expressed as follows:

[0189]

number

[0190] 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.

[0191] 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].

[0192] (Supplementary Note 2) Naturally, the embodiments and other contents described in this specification may be combined and implemented.

[0193] 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.

[0194] Regarding the modulation method, even if a modulation method other than the modulation methods described in this specification is used, it is possible to implement the embodiments and other contents described in this specification. 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 (Phase Shift Keying) (e.g., BPSK, QPSK, 8PSK, 16PSK, 64PSK, 128PSK, 256PSK, 1024PSK, 4096PSK, etc.), QAM (Quadrature Amplitude Modulation) (e.g., 4QAM, 8QAM, 16QAM, 64QAM, 128QAM, For each modulation method, uniform mapping or non-uniform mapping may be used.

[0195] 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 specification. Therefore, the function of outputting in-phase components and quadrature components based on a plurality of bits is the function of the mapping unit, and then performing precoding and phase change is one effective function of the present invention.

[0196] In this specification, when "∀" and "∃" are present, "∀" represents a universal quantifier, and "∃" represents an existential quantifier.

[0197] Furthermore, in this specification, when there is a complex plane, the unit of phase, such as the argument, is "radian."

[0198] Using the complex plane, complex numbers can be displayed in polar form as polar coordinates. When a point (a, b) on the complex plane corresponds to the complex number z = a + jb (both 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 × cos θ, b = r × sin θ.

number

[0199] In this specification, 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 then performs subsequent processing.

[0200] The data and information obtained by the receiving device is then converted into video and sound, which are then displayed on a display (monitor) or output from a speaker. Furthermore, the data and information obtained by the receiving device may undergo signal processing for video and sound (or may not require signal processing) and be output from an RCA terminal (video terminal, audio terminal), USB (Universal Serial Bus), HDMI (registered trademark) (High-Definition Multimedia Interface), digital terminal, etc., which the receiving device has.

[0201] In this specification, the transmitting device may be, for example, a communication or broadcasting device 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, a communication device 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 invention may be devices 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.

[0202] 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.

[0203] The pilot symbol may be, for example, a known symbol modulated by PSK modulation in the transmitter / receiver (or the receiver may be able to know the symbol transmitted by the transmitter by synchronizing with the symbol), and the receiver uses this symbol to perform frequency synchronization, time synchronization, channel estimation (for each modulated signal) (CSI (Channel State Information) estimation), signal detection, etc.

[0204] In addition, control information symbols are used to transmit information that needs to be transmitted to the other party in order to realize communication other than data (such as applications) (for example, the modulation method, error correction coding method, coding rate of the error correction coding method used in the communication, setting information in the upper layer, etc.).

[0205] The present invention 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 invention is not limited to this, and the communication method can also be implemented as software.

[0206] 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 weights (matrix) are 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.

[0207] In this specification, terms such as "precoding" and "precoding weight" are used, but the names themselves may be any name, and in the present invention, the signal processing itself is important.

[0208] The streams s1(t) and s2(t) may transmit different data or the same data.

[0209] 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.

[0210] The transmitting device transmits to the receiving device: It is necessary to notify the transmission method (MIMO, SISO, space-time block coding, interleaving), modulation method, and error correction coding method. In some embodiments, it is omitted. to be present in the frame transmitted by the transmitting device, The receiving device will then change its operation accordingly.

[0211] 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).

[0212] 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.

[0213] Furthermore, each configuration of each of the above-described embodiments may be realized as an LSI (Large Scale Integration), which is typically an integrated circuit. These may be individually integrated into a single chip, or a single chip may include all or part of the configuration of each embodiment. While the term "LSI" is used here, it may also be referred to as an IC (Integrated Circuit), system LSI, super LSI, or ultra LSI depending on the level of integration. Furthermore, the method of integration is not limited to LSI, and may be realized using a dedicated circuit or a general-purpose processor. It is also possible to use a field programmable gate array (FPGA), which can be programmed after LSI fabrication, or a reconfigurable processor, which allows the connections and settings of circuit cells within LSI to be reconfigured.

[0214] 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.

[0215] The present invention 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).

[0216] (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.

[0217] 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.

[0218] 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.

[0219] 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 (corresponding to mapped signal 105_1 in FIG. 1), mapped signal 201B (corresponding to mapped signal 105_2 in FIG. 1), and control signal 200 (corresponding to control signal 100 in FIG. 1), performs pre-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 is, for example, time. (s1(t), s2(t), z1(t), z2'(t) are defined as complex numbers (therefore, they may be real numbers).) Here, it is treated as a function of time, but it may be a function of "frequency (carrier number)", or a function of "time-frequency". It may also be a function of "symbol number". This is also the case in the first embodiment.

[0220] The weighting and combining unit (precoding unit) 203 performs the calculation of equation (1).

[0221] 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 (or may be a real number).

[0222] 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). (i is the symbol number (i is an integer equal to or greater than 0))

[0223] 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.) (Setting N to an odd number equal to or greater than 3 may improve the data reception quality.) 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 will be expressed as:

[0224] 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 methods of periodically and regularly changing the phase are also possible.

[0225] As explained in the first embodiment, the (precoding) matrices in equations (1) and (3) can be equations (5) to (36), etc. (however, the precoding matrices are not limited to these (the same applies to the first embodiment).)

[0226] Insertion section 207A receives weighted combined signal 204A, pilot symbol signal (pa(t)) (t: time) (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.

[0227] Similarly, insertion unit 207B receives phase-changed 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.

[0228] 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 (i is an integer equal to or greater than 0), expressed as x'(i). Then, phase-changed signal 210A(x(i)) is expressed as x(i)=e j×ε(i) × x'(i) (j is the imaginary unit).

[0229] As described in the first embodiment and the like, the operation of phase changer 209A may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209A is characterized in that it performs phase change on symbols present in the frequency axis direction (applying phase change to data symbols, pilot symbols, control information symbols, etc.).

[0230] 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.

[0231] 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.

[0232] 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.

[0233] 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 will be 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.

[0234] The other symbols in Figures 4 and 5 are symbols corresponding to "preamble signal 252 and control information symbol signal 253 in Figure 2." Therefore, if other symbols 503 in Figure 5, which are transmitted at the same time and on the same frequency (same carrier) as other symbols 403 in Figure 4, are transmitting control information, they are transmitting the same data (same control information).

[0235] It is assumed that the receiving device will receive the frames of Figures 4 and 5 simultaneously, but it is possible for the receiving device to obtain the data transmitted by the transmitting device even if it receives only the frame of Figure 4 or only the frame of Figure 5.

[0236] 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.

[0237] Figure 7 shows an example of the configuration of antenna unit #A (109_A) and antenna unit #B (109_B) in Figure 1 (an example in which antenna unit #A (109_A) and antenna unit #B (109_B) are configured with multiple antennas), and since a detailed explanation has been given in embodiment 1, a detailed explanation will be omitted.

[0238] 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.

[0239] Fig. 10 shows an example of the configuration of antenna unit #X (801X) and antenna unit #Y (801Y) in Fig. 8. (This is 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.

[0240] 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.

[0241] As explained using Figures 4 and 5, phase change section 205B performs precoding (weighted combining) on mapped signal s1(i) (201A) (where i is a symbol number and is an integer equal to or greater than 0) obtained by mapping using a first sequence and mapped signal s2(i) (201B) obtained by mapping using a second sequence, and then performs a phase change on one of the resulting weighted combined signals 204A, 204B. Then, weighted combined signal 204A and 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 performed on data symbol 502 in Figure 5. (In the case of FIG. 18, phase change section 205 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.)

[0242] For example, Figure 11 shows carrier 1 to carrier 5 and time $4 to time $6 extracted from the frame in Figure 5. As in Figure 5, 501 is a pilot symbol, 502 is a data symbol, and 503 is other symbols.

[0243] As described above, in the symbols shown in FIG. 11, phase change unit 205B applies phase change to the (carrier 1, time $5) data symbol, (carrier 2, time $5) data symbol, (carrier 3, time $5) data symbol, (carrier 4, time $5) data symbol, (carrier 5, time $5) data symbol, (carrier 1, time $6) data symbol, (carrier 2, time $6) data symbol, (carrier 4, time $6) data symbol, and (carrier 5, time $6) data symbol.

[0244] Therefore, in the symbols shown in FIG. 11, the phase change value of the data symbol (carrier 1, time $5) is set as "e j×δ15(i) " and the phase change value of the data symbol (carrier 2, time $5) is "e j×δ25(i) " and the phase change value of the data symbol (carrier 3, time $5) is "e j×δ35(i) " and the phase change value of the data symbol (carrier 4, time $5) is "e j×δ45(i) " and the phase change value of the data symbol (carrier 5, time $5) is "e j×δ55(i) " and the phase change value of the data symbol (carrier 1, time $6) is "e j×δ16(i) " and the phase change value of the data symbol (carrier 2, time $6) is "e j×δ26(i) " and the phase change value of the data symbol (carrier 4, time $6) is "e j×δ46(i) " and the phase change value of the data symbol (carrier 5, time $6) is "e j×δ56(i) "

[0245] On the other hand, in the symbols shown in Figure 11, other symbols of (carrier 1, time $4), other symbols of (carrier 2, time $4), other symbols of (carrier 3, time $4), other symbols of (carrier 4, time $4), other symbols of (carrier 5, time $4), and pilot symbols of (carrier 3, time $6) are not subject to phase modification by phase modification unit 205B.

[0246] This is a characteristic feature of phase changer 205B. Note that, as shown in Fig. 4, data carriers are arranged at the "same carrier, same time" as the (carrier 1, time $5) data symbol, (carrier 2, time $5) data symbol, (carrier 3, time $5) data symbol, (carrier 4, time $5) data symbol, (carrier 5, time $5) data symbol, (carrier 1, time $6) data symbol, (carrier 2, time $6) data symbol, (carrier 4, time $6) data symbol, and (carrier 5, time $6) data symbol, which are the targets of phase change in Fig. 11. 4, (carrier 1, time $5) is a data symbol, (carrier 2, time $5) is a data symbol, (carrier 3, time $5) is a data symbol, (carrier 4, time $5) is a data symbol, (carrier 5, time $5) is a data symbol, (carrier 1, time $6) is a data symbol, (carrier 2, time $6) is a data symbol, (carrier 4, time $6) is a data symbol, and (carrier 5, time $6) is a data symbol. (In other words, data symbols undergoing MIMO transmission (transmitting multiple streams) are the targets of phase modification by phase modification section 205B.)

[0247] An example of the phase change that phase change unit 205B applies to the data symbols is a method of performing regular phase change (phase change period N) on the data symbols as shown in equation (2). (However, the method of phase change applied to the data symbols is not limited to this.)

[0248] By doing so, in an environment where direct waves are dominant, particularly in an LOS environment, it is possible to obtain the effect of improving the reception quality of data at a receiving device for data symbols undergoing MIMO transmission (transmitting multiple streams). This effect will now be explained.

[0249] For example, assume that the modulation scheme used in mapping section 104 in FIG. 1 is QPSK (Quadrature Phase Shift Keying). (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.) Then, signal processing section 811 in FIG. 8 uses, for example, channel estimation signals 806_1 and 806_2 to obtain 16 candidate signal points. (QPSK can transmit 2 bits, and a total of 4 bits are transmitted using 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.)

[0250] An example of this state is shown in Figure 12. In both Figures 12(A) and 12(B), 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. (Of the 16 candidate signal points, one is the signal point transmitted by the transmitting device. For this reason, they are called "16 candidate signal points.")

[0251] In an environment where direct waves are dominant, especially in an LOS environment, First case: When the phase change unit 205B of FIG. 18 does not exist (that is, when the phase change unit 205B of FIG. 18 does not perform phase change) Think about it.

[0252] In the "first case," no phase change is performed, which may result in a state like that shown in (A) of Fig. 12. If the state shown in (A) of Fig. 12 occurs, there will be areas where signal points are dense (signal points are close together), such as "signal points 1201 and 1202," "signal points 1203, 1204, 1205, 1206," and "signal points 1207, 1208," which may result in a decrease in data reception quality in the receiving device of Fig. 8.

[0253] To overcome this problem, phase shifter 205B is inserted in Fig. 18. When phase shifter 205B is inserted, the symbol number i will contain a mixture of symbol numbers where signal points are dense (the distance between signal points is short) as in Fig. 12(A) and symbol numbers where the distance between signal points is long as shown in Fig. 12(B). To address this situation, an error correction code is introduced, which makes it possible to obtain high error correction capability and high data reception quality in the receiving device of Fig. 8.

[0254] 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, in the data symbols, "a mixture of symbol numbers where, depending on symbol number i, there are parts where signal points are dense (the distance between signal points is short) as in Fig. 12(A) and symbol numbers where "the distance between signal points is long" as in Fig. 12(B)."

[0255] However, even if the phase shifter 205B in FIG. 18 performs phase shifting on the pilot symbols and preambles used for channel estimation to demodulate (detect) data symbols, there may be cases where the data symbols include a mixture of symbol numbers with dense signal points (close distances between signal points) as shown in FIG. 12(A) and symbol numbers with long distances between signal points as shown in FIG. 12(B). In this case, some conditions must be imposed on the pilot symbols and preambles to perform the phase shifting. For example, a method can be considered in which a different rule is established from the phase shifting rule for data symbols to perform the phase shifting on pilot symbols and / or preambles. For example, a method can be used in which the phase shifting is performed regularly with a period N on data symbols and a period M on pilot symbols and / or preambles. (N and M are integers equal to or greater than 2.)

[0256] As described above, 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 (i is an integer equal to or greater than 0), expressed as x'(i). Then, phase-changed 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 (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209A is characterized in that it performs phase change on symbols present in the frequency axis direction (it 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.)). (In the case of FIG. 18, phase changer 209A performs phase change on baseband signal 208A, and therefore performs phase change on each symbol shown in FIG. 4.)

[0257] Therefore, in the frame of FIG. 4, phase change section 209A of FIG. 18 applies phase change to all symbols from carrier 1 to carrier 36 at time $1 (in this case, all are other symbols 403).

[0258] Similarly, "Phase change unit 209A in FIG. 18 performs phase change on all symbols from carrier 1 to carrier 36 at time $2 (in this case, all are other symbols 403)." "Phase change unit 209A in FIG. 18 performs a phase change on all symbols from carrier 1 to carrier 36 at time $3 (in this case, all are other symbols 403)." "Phase change unit 209A in FIG. 18 applies phase change to all symbols from carrier 1 to carrier 36 at time $4 (in this case, all are other symbols 403)." "Phase change section 209A in FIG. 18 performs phase change on all symbols from carrier 1 to carrier 36 at time $5 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 18 performs phase change on all symbols from carrier 1 to carrier 36 at time $6 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 18 performs phase change on all symbols from carrier 1 to carrier 36 at time $7 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 18 performs phase change on all symbols from carrier 1 to carrier 36 at time $8 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 18 performs phase change on all symbols from carrier 1 to carrier 36 at time $9 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 18 performs phase change on all symbols from carrier 1 to carrier 36 at time $10 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 18 performs phase change on all symbols from carrier 1 to carrier 36 at time $11 (in this case, pilot symbol 401 or data symbol 402)." ...

[0259] 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.

[0260] 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.

[0261] 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 will be transmitted at the same time and on the same frequency. Note that the frame structures in Figures 13 and 14 are merely examples.

[0262] The other symbols in Figures 13 and 14 are symbols equivalent to "preamble signal 252 and control information symbol signal 253 in Figure 18." Therefore, if other symbol 503 in Figure 14, which is transmitted at the same time and on the same frequency (same carrier) as other symbol 403 in Figure 13, is transmitting control information, it is transmitting the same data (same control information).

[0263] It is assumed that the receiving device will receive the frames of Figures 13 and 14 simultaneously, but it is possible for the receiving device to obtain the data transmitted by the transmitting device even if it receives only the frame of Figure 13 or only the frame of Figure 14.

[0264] 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 (i is an integer equal to or greater than 0), expressed as x'(i). Then, phase-changed signal 210A(x(i)) is expressed as x(i)=e j×ε(i)×x′(i) (j is an imaginary unit). The operation of the phase changer 209A may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Documents 2 and 3. Phase modification unit 209A is characterized in that it performs a phase modification on symbols existing in the frequency axis direction (phase modifications are performed on data symbols, pilot symbols, control information symbols, etc. At this time, null symbols can also be considered to be targets of phase modification. (Accordingly, in this case, the symbols targeted by symbol number i are data symbols, pilot symbols, control information symbols, preambles (other symbols), null symbols, etc.). However, even if a phase modification is performed on a null symbol, the signal before and after the phase modification are the same (in-phase component I is zero (0), and quadrature component Q is zero (0)). Therefore, it is also possible to interpret null symbols as not being targets of phase modification. (In the case of FIG. 18, phase modification unit 209A performs a phase modification on baseband signal 208A, and therefore performs a phase modification on each symbol shown in FIG. 13.)

[0265] Therefore, in the frame of Fig. 13, phase change section 209A of Fig. 18 applies phase change to all symbols from carrier 1 to carrier 36 at time $1 (in this case, all are other symbols 403). However, the handling of phase change for null symbol 1301 is as explained above.

[0266] Similarly, "For all symbols from carrier 1 to carrier 36 at time $2 (in this case, all are other symbols 403), phase change unit 209A in FIG. 18 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $3 (in this case, all are other symbols 403), phase change unit 209A in FIG. 18 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $4 (in this case, all are other symbols 403), phase change unit 209A in FIG. 18 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols of carrier 1 to carrier 36 at time $5 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 18 performs phase change. However, handling of phase change of null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $6 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 18 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $7 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 18 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $8 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 18 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $9 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 18 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $10 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 18 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $11 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 18 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." ...

[0267] 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.

[0268] 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 the imaginary unit) However, equation (38) is merely an example and is not limited to this.

[0269] For example, Ω(i) may be set to perform a phase change with a period Q.

[0270] 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. For carrier 4 in Figures 4 and 13, the phase change value is set to equation (42) regardless of time. ...

[0271] The above is an example of the operation of the phase changer 209A in FIG.

[0272] The effects obtained by the phase changing section 209A in FIG. 18 will be described.

[0273] It is assumed that the other symbols 403, 503 in the "frames of Figs. 4 and 5" or "frames of Figs. 13 and 14" contain control information symbols. As explained above, if the other symbols 503 in Fig. 5, which are transmitted at the same time and on the same frequency (same carrier) as the other symbols 403, transmit control information, they transmit the same data (same control information).

[0274] Now, consider the following case.

[0275] Case 2: The control information symbols are transmitted using either antenna unit #A (109_A) or antenna unit #B (109_B) in FIG.

[0276] When transmitting as in "Case 2," the number of antennas transmitting 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)."

[0277] Case 3: Control information symbols are transmitted using both antenna unit #A (109_A) and antenna unit #B (109_B) in Fig. 1. However, no phase change is performed in phase change unit 209A in Fig. 18.

[0278] 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 there is 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 poses a problem in that the receiving device in Figure 8 may experience a decrease in data reception quality.

[0279] To alleviate this problem, 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 will be 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 will be obtained, which will improve the data reception quality in the receiving device of Fig. 8.

[0280] For the above reasons, in FIG. 18, a phase change section 209A is provided to change the phase.

[0281] 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 (symbols for estimating propagation path fluctuations) for demodulating and decoding 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.

[0282] 4 and 5 or the frames of FIGS. 13 and 14, multiple streams are transmitted (MIMO transmission is performed) using the same frequency (band) and the same time using data symbols 402 and data symbols 502. To demodulate these data symbols, other symbols 403 and other symbols 503 are used, including symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation (symbols for estimating propagation path fluctuations).

[0283] At this time, as mentioned above, the phases of "other symbols 403 and other symbols 503, which are included in the symbols for signal detection, the symbols for frequency synchronization and time synchronization, and the symbols for channel estimation (symbols for estimating propagation path fluctuations)" are changed by phase change unit 209A.

[0284] Under such circumstances, if this processing is not reflected on data symbol 402 and data symbol 502 (in 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. (This is because the phases of "symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation (symbols for estimating propagation path fluctuations) included in other symbols 403 and other symbols 503" have been changed by phase change unit 209A.)

[0285] However, as shown in FIG. 18, 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 (symbols for estimating propagation path fluctuation)."

[0286] 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.

[0287] 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.

[0288] 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, particularly 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 of 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.

[0289] 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, particularly 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.

[0290] 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.

[0291] (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.

[0292] 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.

[0293] 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.

[0294] 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 (corresponding to mapped signal 105_1 in FIG. 1), mapped signal 201B (corresponding to mapped signal 105_2 in FIG. 1), and control signal 200 (corresponding to control signal 100 in FIG. 1), performs pre-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 is, for example, time. (s1(t), s2(t), z1(t), z2'(t) are defined as complex numbers (therefore, they may be real numbers).)

[0295] Here, it is treated as a function of time, but it may be a function of "frequency (carrier number)", or a function of "time-frequency". It may also be a function of "symbol number". This is also the case in the first embodiment.

[0296] The weighting and combining unit (precoding unit) 203 performs the calculation of equation (1).

[0297] 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 (or may be a real number).

[0298] 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). (i is the symbol number (i is an integer equal to or greater than 0))

[0299] 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.) (Setting N to an odd number equal to or greater than 3 may improve the data reception quality.) 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 will be expressed as:

[0300] 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 methods of periodically and regularly changing the phase are also possible.

[0301] As explained in the first embodiment, the (precoding) matrices in equations (1) and (3) can be equations (5) to (36), etc. (however, the precoding matrices are not limited to these (the same applies to the first embodiment).)

[0302] Insertion section 207A receives weighted combined signal 204A, pilot symbol signal (pa(t)) (t: time) (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.

[0303] Similarly, insertion unit 207B receives phase-changed 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.

[0304] 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 (i is an integer equal to or greater than 0), expressed as x'(i). Then, phase-changed signal 210A(x(i)) is expressed as x(i)=e j×ε(i) × x'(i) (j is the imaginary unit).

[0305] As described in the first embodiment and the like, the operation of phase changer 209A may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209A is characterized in that it performs phase change on symbols present in the frequency axis direction (applying phase change to data symbols, pilot symbols, control information symbols, etc.).

[0306] 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 y'(i). Then, phase-changed signal 210B(y(i)) is expressed as y(i)=e j×τ(i) × y'(i) (j is the imaginary unit).

[0307] As described in the first embodiment and the like, the operation of phase changer 209B may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209B is characterized in that it performs phase change on symbols present in the frequency axis direction (applying phase change to data symbols, pilot symbols, control information symbols, etc.).

[0308] A 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 cyclic delay amount of CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) set by phase changer 209A is different from the value of the cyclic delay amount of CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) set by phase changer 209B.

[0309] 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.

[0310] 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.

[0311] 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.

[0312] 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 will be 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.

[0313] The other symbols in Figures 4 and 5 are symbols corresponding to "preamble signal 252 and control information symbol signal 253 in Figure 2." Therefore, if other symbols 503 in Figure 5, which are transmitted at the same time and on the same frequency (same carrier) as other symbols 403 in Figure 4, are transmitting control information, they are transmitting the same data (same control information).

[0314] It is assumed that the receiving device will receive the frames of Figures 4 and 5 simultaneously, but it is possible for the receiving device to obtain the data transmitted by the transmitting device even if it receives only the frame of Figure 4 or only the frame of Figure 5.

[0315] 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.

[0316] Figure 7 shows an example of the configuration of antenna unit #A (109_A) and antenna unit #B (109_B) in Figure 1 (an example in which antenna unit #A (109_A) and antenna unit #B (109_B) are configured with multiple antennas), and since a detailed explanation has been given in embodiment 1, a detailed explanation will be omitted.

[0317] 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.

[0318] Fig. 10 shows an example of the configuration of antenna unit #X (801X) and antenna unit #Y (801Y) in Fig. 8. (This is 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.

[0319] Next, as shown in Fig. 1, signal processing unit 106 of the transmitting device has phase change unit 205B and phase change units 209A and 209B inserted therein, as shown in Fig. 19. The features and effects of this will be described.

[0320] As explained using Figures 4 and 5, phase change section 205B performs precoding (weighted combining) on mapped signal s1(i) (201A) (where i is a symbol number and is an integer equal to or greater than 0) obtained by mapping using a first sequence and mapped signal s2(i) (201B) obtained by mapping using a second sequence, and then performs a phase change on one of the resulting weighted combined signals 204A, 204B. Then, weighted combined signal 204A and 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 performed on data symbol 502 in Figure 5. (In the case of FIG. 19, phase change section 205 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.)

[0321] For example, Figure 11 shows carrier 1 to carrier 5 and time $4 to time $6 extracted from the frame in Figure 5. As in Figure 5, 501 is a pilot symbol, 502 is a data symbol, and 503 is other symbols.

[0322] As described above, in the symbols shown in FIG. 11, phase change unit 205B applies phase change to the (carrier 1, time $5) data symbol, (carrier 2, time $5) data symbol, (carrier 3, time $5) data symbol, (carrier 4, time $5) data symbol, (carrier 5, time $5) data symbol, (carrier 1, time $6) data symbol, (carrier 2, time $6) data symbol, (carrier 4, time $6) data symbol, and (carrier 5, time $6) data symbol.

[0323] Therefore, in the symbols shown in FIG. 11, the phase change value of the data symbol (carrier 1, time $5) is set as "e j×δ15(i)" and the phase change value of the data symbol (carrier 2, time $5) is "e j×δ25(i) " and the phase change value of the data symbol (carrier 3, time $5) is "e j×δ35(i) " and the phase change value of the data symbol (carrier 4, time $5) is "e j×δ45(i) " and the phase change value of the data symbol (carrier 5, time $5) is "e j×δ55(i) " and the phase change value of the data symbol (carrier 1, time $6) is "e j×δ16(i) " and the phase change value of the data symbol (carrier 2, time $6) is "e j×δ26(i) " and the phase change value of the data symbol (carrier 4, time $6) is "e j×δ46(i) " and the phase change value of the data symbol (carrier 5, time $6) is "e j×δ56(i) "

[0324] On the other hand, in the symbols shown in Figure 11, other symbols of (carrier 1, time $4), other symbols of (carrier 2, time $4), other symbols of (carrier 3, time $4), other symbols of (carrier 4, time $4), other symbols of (carrier 5, time $4), and pilot symbols of (carrier 3, time $6) are not subject to phase modification by phase modification unit 205B.

[0325] This is a characteristic feature of phase changer 205B. Note that, as shown in Fig. 4, data carriers are arranged at the "same carrier, same time" as the (carrier 1, time $5) data symbol, (carrier 2, time $5) data symbol, (carrier 3, time $5) data symbol, (carrier 4, time $5) data symbol, (carrier 5, time $5) data symbol, (carrier 1, time $6) data symbol, (carrier 2, time $6) data symbol, (carrier 4, time $6) data symbol, and (carrier 5, time $6) data symbol, which are the targets of phase change in Fig. 11. 4, (carrier 1, time $5) is a data symbol, (carrier 2, time $5) is a data symbol, (carrier 3, time $5) is a data symbol, (carrier 4, time $5) is a data symbol, (carrier 5, time $5) is a data symbol, (carrier 1, time $6) is a data symbol, (carrier 2, time $6) is a data symbol, (carrier 4, time $6) is a data symbol, and (carrier 5, time $6) is a data symbol. (In other words, data symbols undergoing MIMO transmission (transmitting multiple streams) are the targets of phase modification by phase modification section 205B.)

[0326] An example of the phase change that phase change unit 205B applies to the data symbols is a method of performing regular phase change (phase change period N) on the data symbols as shown in equation (2). (However, the method of phase change applied to the data symbols is not limited to this.)

[0327] By doing so, in an environment where direct waves are dominant, particularly in an LOS environment, it is possible to obtain the effect of improving the reception quality of data at a receiving device for data symbols undergoing MIMO transmission (transmitting multiple streams). This effect will now be explained.

[0328] For example, assume that the modulation scheme used in mapping section 104 in FIG. 1 is QPSK (Quadrature Phase Shift Keying). (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.) Then, signal processing section 811 in FIG. 8 uses, for example, channel estimation signals 806_1 and 806_2 to obtain 16 candidate signal points. (QPSK can transmit 2 bits, and a total of 4 bits are transmitted using 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.)

[0329] An example of this state is shown in Figure 12. In both Figures 12(A) and 12(B), 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. (Of the 16 candidate signal points, one is the signal point transmitted by the transmitting device. For this reason, they are called "16 candidate signal points.")

[0330] In an environment where direct waves are dominant, especially in an LOS environment, First case: When the phase change unit 205B of FIG. 19 does not exist (that is, when the phase change unit 205B of FIG. 19 does not perform phase change) Think about it.

[0331] In the "first case," no phase change is performed, which may result in a state like that shown in (A) of Fig. 12. If the state shown in (A) of Fig. 12 occurs, there will be areas where signal points are dense (signal points are close together), such as "signal points 1201 and 1202," "signal points 1203, 1204, 1205, 1206," and "signal points 1207, 1208," which may result in a decrease in data reception quality in the receiving device of Fig. 8.

[0332] To overcome this problem, phase shifter 205B is inserted in Fig. 19. When phase shifter 205B is inserted, the symbol number i will contain a mixture of symbol numbers where signal points are dense (the distance between signal points is short) as in Fig. 12(A) and symbol numbers where the distance between signal points is long as shown in Fig. 12(B). In this situation, error correction coding is introduced, which makes it possible to obtain high error correction capability and high data reception quality in the receiving device of Fig. 8.

[0333] 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 the data symbols, "a mixture of symbol numbers where, depending on symbol number i, there are parts where signal points are dense (the distance between signal points is short) as in Fig. 12(A) and symbol numbers where "the distance between signal points is long" as in Fig. 12(B)."

[0334] However, even if the phase shifter 205B in FIG. 19 performs phase shifting on the pilot symbols and preambles used for channel estimation to demodulate (detect) data symbols, there may be cases where the data symbols include a mixture of symbol numbers with dense signal points (close distances between signal points) as shown in FIG. 12(A) and symbol numbers with long distances between signal points as shown in FIG. 12(B). In this case, some conditions must be imposed on the pilot symbols and preambles to perform the phase shifting. For example, a method can be considered in which a different rule is established from the rule for phase shifting on data symbols to perform phase shifting on pilot symbols and / or preambles. For example, a method can be used in which the phase shifting is performed on data symbols regularly with a period N, and on pilot symbols and / or preambles regularly with a period M (N and M are integers equal to or greater than 2).

[0335] As described above, 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 (i is an integer equal to or greater than 0), expressed as x'(i). Then, phase-changed 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 (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209A is characterized in that it performs phase change on symbols present in the frequency axis direction (it 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.)). (In the case of FIG. 19, phase changer 209A performs phase change on baseband signal 208A, and therefore performs phase change on each symbol shown in FIG. 4.)

[0336] Therefore, in the frame of FIG. 4, phase change section 209A of FIG. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $1 (in this case, all are other symbols 403).

[0337] Similarly, "Phase change unit 209A in FIG. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $2 (in this case, all are other symbols 403)." "Phase change unit 209A in FIG. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $3 (in this case, all are other symbols 403)." "Phase change unit 209A in FIG. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $4 (in this case, all are other symbols 403)." "Phase change section 209A in FIG. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $5 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $6 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $7 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $8 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 19 performs phase change on all symbols from carrier 1 to carrier 36 at time $9 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $10 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 19 performs phase change on all symbols from carrier 1 to carrier 36 at time $11 (in this case, pilot symbol 401 or data symbol 402)." ...

[0338] 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 (i is an integer equal to or greater than 0), expressed as y'(i). Then, phase-changed signal 210B(y(i)) is expressed as y(i)=e j×τ(i)×y'(i) (j is the imaginary unit). The operation of phase changer 209B may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209B is characterized in that it performs phase change on symbols present in the frequency axis direction (it 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.)). (In the case of FIG. 19, phase changer 209B performs phase change on baseband signal 208B, and therefore performs phase change on each symbol shown in FIG. 5.)

[0339] Therefore, in the frame of FIG. 5, phase change section 209B of FIG. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $1 (in this case, all are other symbols 503).

[0340] Similarly, "Phase change unit 209B in FIG. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $2 (in this case, all are other symbols 503)." "Phase change unit 209B in FIG. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $3 (in this case, all are other symbols 503)." "Phase change unit 209B in FIG. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $4 (in this case, all are other symbols 503)." "Phase change section 209B in FIG. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $5 (in this case, pilot symbol 501 or data symbol 502)." "Phase change section 209B in FIG. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $6 (in this case, pilot symbol 501 or data symbol 502)." "Phase change section 209B in FIG. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $7 (in this case, pilot symbol 501 or data symbol 502)." "Phase change section 209B in FIG. 19 performs phase change on all symbols from carrier 1 to carrier 36 at time $8 (in this case, pilot symbol 501 or data symbol 502)." "Phase change section 209B in FIG. 19 performs phase change on all symbols from carrier 1 to carrier 36 at time $9 (in this case, pilot symbol 501 or data symbol 502)." "Phase change section 209B in FIG. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $10 (in this case, pilot symbol 501 or data symbol 502)." "Phase change section 209B in FIG. 19 performs phase change on all symbols from carrier 1 to carrier 36 at time $11 (in this case, pilot symbol 501 or data symbol 502)."

[0341] 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.

[0342] 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.

[0343] 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 will be transmitted at the same time and on the same frequency. Note that the frame structures in Figures 13 and 14 are merely examples.

[0344] The other symbols in Figures 13 and 14 are symbols equivalent to "preamble signal 252 and control information symbol signal 253 in Figure 19." Therefore, if other symbol 503 in Figure 14, which is transmitted at the same time and on the same frequency (same carrier) as other symbol 403 in Figure 13, is transmitting control information, it is transmitting the same data (same control information).

[0345] It is assumed that the receiving device will receive the frames of Figures 13 and 14 simultaneously, but it is possible for the receiving device to obtain the data transmitted by the transmitting device even if it receives only the frame of Figure 13 or only the frame of Figure 14.

[0346] 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 (i is an integer equal to or greater than 0), expressed as x'(i). Then, phase-changed signal 210A(x(i)) is expressed as x(i)=e j×ε(i)×x′(i) (j is an imaginary unit). The operation of the phase changer 209A may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Documents 2 and 3. Phase modification unit 209A is characterized in that it performs a phase modification on symbols existing in the frequency axis direction (phase modifications are performed on data symbols, pilot symbols, control information symbols, etc. At this time, null symbols can also be considered to be targets of phase modification. (Accordingly, in this case, the symbols that are targets of symbol number i are data symbols, pilot symbols, control information symbols, preambles (other symbols), null symbols, etc.). However, even if a phase modification is performed on a null symbol, the signal before and after the phase modification are the same (in-phase component I is zero (0), and quadrature component Q is zero (0)). Therefore, it is also possible to interpret that null symbols are not targets of phase modification. (In the case of FIG. 19, phase modification unit 209A performs a phase modification on baseband signal 208A, and therefore performs a phase modification on each symbol shown in FIG. 13.)

[0347] Therefore, in the frame of Fig. 13, phase change section 209A of Fig. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $1 (in this case, all are other symbols 403). However, the handling of phase change for null symbol 1301 is as explained above.

[0348] Similarly, "For all symbols from carrier 1 to carrier 36 at time $2 (in this case, all are other symbols 403), phase change unit 209A in FIG. 19 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $3 (in this case, all are other symbols 403), phase change unit 209A in FIG. 19 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $4 (in this case, all are other symbols 403), phase change unit 209A in FIG. 19 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $5 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 19 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $6 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 19 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $7 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 19 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $8 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 19 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $9 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 19 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $10 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 19 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $11 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 19 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." ...

[0349] 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.

[0350] 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 the imaginary unit) However, equation (38) is merely an example and is not limited to this.

[0351] For example, Ω(i) may be set to perform a phase change with a period Q.

[0352] 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. For carrier 4 in Figures 4 and 13, the phase change value is set to equation (42) regardless of time. ...

[0353] The above is an example of the operation of the phase changer 209A in FIG.

[0354] 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 y'(i). Then, phase-changed signal 210B(y(i)) is expressed as y(i)=e j×τ(i) ×y′(i) (j is an imaginary unit). The operation of the phase changer 209B may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Documents 2 and 3. Phase modification unit 209B is characterized in that it performs a phase modification on symbols existing in the frequency axis direction (phase modifications are performed on data symbols, pilot symbols, control information symbols, etc. At this time, null symbols can also be considered to be targets of phase modification. (Accordingly, in this case, the symbols targeted by symbol number i are data symbols, pilot symbols, control information symbols, preambles (other symbols), null symbols, etc.). However, even if a phase modification is performed on a null symbol, the signal before and after the phase modification are the same (the in-phase component I is zero (0), and the quadrature component Q is zero (0)). Therefore, it is also possible to interpret null symbols as not being targets of phase modification. (In the case of FIG. 19, phase modification unit 209B performs a phase modification on baseband signal 208B, and therefore performs a phase modification on each symbol shown in FIG. 14.)

[0355] Therefore, in the frame of Fig. 14, phase change section 209B of Fig. 19 applies phase change to all symbols from carrier 1 to carrier 36 at time $1 (in this case, all are other symbols 503). However, the handling of phase change for null symbol 1301 is as explained above.

[0356] Similarly, "For all symbols from carrier 1 to carrier 36 at time $2 (in this case, all are other symbols 503), phase change unit 209B in FIG. 19 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $3 (in this case, all are other symbols 503), phase change unit 209B in FIG. 19 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $4 (in this case, all are other symbols 503), phase change unit 209B in FIG. 19 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols of carrier 1 to carrier 36 at time $5 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 19 applies phase change. However, handling of phase change of null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $6 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 19 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $7 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 19 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $8 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 19 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $9 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 19 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $10 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 19 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $11 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 19 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." ...

[0357] 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.

[0358] For example, the phase change value is set as follows: (R is an integer of 2 or more, and R is the period of the phase change. It is preferable that the values of Q and R in equation (38) are different.)

[0359]

number

[0360] For example, Δ(i) may be set to change the phase to have a period R.

[0361] It should be noted that the phase change methods of phase changer 209A and phase changer 209B are different. For example, the cycles may be the same or different.

[0362] 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. For carrier 4 in Figures 5 and 14, the phase change value is set to equation (42) regardless of time. ...

[0363] (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.)

[0364] The above is an example of the operation of the phase changer 209B in FIG.

[0365] The effects obtained by the phase change units 209A and 209B in FIG. 19 will be described.

[0366] It is assumed that the other symbols 403, 503 in the "frames of Figs. 4 and 5" or "frames of Figs. 13 and 14" contain control information symbols. As explained above, if the other symbols 503 in Fig. 5, which are transmitted at the same time and on the same frequency (same carrier) as the other symbols 403, transmit control information, they transmit the same data (same control information).

[0367] Now, consider the following case.

[0368] Case 2: The control information symbols are transmitted using either antenna unit #A (109_A) or antenna unit #B (109_B) in FIG.

[0369] When transmitting as in "Case 2," the number of antennas transmitting 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)."

[0370] 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 units 209A and 209B in Fig. 19.

[0371] 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 there is 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 poses a problem in that the receiving device in Figure 8 may experience a decrease in data reception quality.

[0372] To alleviate this problem, 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 will be 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 will be obtained, which will improve the data reception quality in the receiving device of Fig. 8.

[0373] For the above reasons, in FIG. 19, phase change sections 209A and 209B are provided to change the phase.

[0374] 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 (symbols for estimating propagation path fluctuations) for demodulating and decoding 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.

[0375] 4 and 5 or the frames of FIGS. 13 and 14, multiple streams are transmitted (MIMO transmission is performed) using the same frequency (band) and the same time using data symbols 402 and data symbols 502. To demodulate these data symbols, other symbols 403 and other symbols 503 are used, including symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation (symbols for estimating propagation path fluctuations).

[0376] At this time, as mentioned above, the phases of "symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation (symbols for estimating propagation path fluctuations) included in other symbols 403 and other symbols 503" are changed by phase change units 209A and 209B.

[0377] Under such circumstances, if this processing is not reflected in data symbol 402 and 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 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 (symbols for estimating propagation path fluctuations) included in other symbols 403 and other symbols 503" have been changed by phase change units 209A and 209B.)

[0378] 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 (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 symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation (symbols for estimating propagation path fluctuation) contained in other symbols 503."

[0379] 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.

[0380] 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.

[0381] 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, particularly 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 of 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.

[0382] 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, particularly 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.

[0383] 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.

[0384] 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.

[0385] Furthermore, taking into consideration the content explained in Supplementary Note 1, it would be better 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.

[0386] (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.

[0387] 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.

[0388] 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.

[0389] 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 (corresponding to mapped signal 105_1 in FIG. 1), mapped signal 201B (corresponding to mapped signal 105_2 in FIG. 1), and control signal 200 (corresponding to control signal 100 in FIG. 1), performs pre-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 is, for example, time. (s1(t), s2(t), z1'(t), z2'(t) are defined as complex numbers (therefore, they may be real numbers).)

[0390] Here, it is treated as a function of time, but it may be a function of "frequency (carrier number)", or a function of "time-frequency". It may also be a function of "symbol number". This is also the case in the first embodiment.

[0391] The weighting synthesis unit (precoding unit) 203 performs the following calculation.

[0392]

number

[0393] 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), where z1(t) is defined as a complex number (it may also be a real number).

[0394] 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). (i is the symbol number (i is an integer equal to or greater than 0))

[0395] For example, the phase change value is set as follows:

[0396]

number

[0397] 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 (or may be a real number).

[0398] 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). (i is the symbol number (i is an integer equal to or greater than 0))

[0399] 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) (Setting N to an odd number equal to or greater than 3 may improve the data reception quality.) 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 will be expressed as:

[0400] In this case, z1(i) and z2(i) can be expressed by the following equations:

[0401]

number

[0402] 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.

[0403] 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 (the same applies to the first embodiment).)

[0404] Insertion section 207A receives weighted combined signal 204A, pilot symbol signal (pa(t)) (t: time) (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.

[0405] Similarly, insertion unit 207B receives phase-changed 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.

[0406] 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) × x'(i) (j is the imaginary unit).

[0407] As described in the first embodiment and the like, the operation of phase changer 209B may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209B is characterized in that it performs phase change on symbols present in the frequency axis direction (applying phase change to data symbols, pilot symbols, control information symbols, etc.).

[0408] 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.

[0409] 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.

[0410] 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.

[0411] 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 will be 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.

[0412] The other symbols in Figures 4 and 5 are symbols corresponding to "preamble signal 252 and control information symbol signal 253 in Figure 2." Therefore, if other symbols 503 in Figure 5, which are transmitted at the same time and on the same frequency (same carrier) as other symbols 403 in Figure 4, are transmitting control information, they are transmitting the same data (same control information).

[0413] It is assumed that the receiving device will receive the frames of Figures 4 and 5 simultaneously, but it is possible for the receiving device to obtain the data transmitted by the transmitting device even if it receives only the frame of Figure 4 or only the frame of Figure 5.

[0414] 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.

[0415] Figure 7 shows an example of the configuration of antenna unit #A (109_A) and antenna unit #B (109_B) in Figure 1 (an example in which antenna unit #A (109_A) and antenna unit #B (109_B) are configured with multiple antennas), and since a detailed explanation has been given in embodiment 1, a detailed explanation will be omitted.

[0416] 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.

[0417] Fig. 10 shows an example of the configuration of antenna unit #X (801X) and antenna unit #Y (801Y) in Fig. 8. (This is 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.

[0418] 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.

[0419] As explained using Figures 4 and 5, phase modification units 205A and 205B perform precoding (weighted combining) on mapped signal s1(i) (201A) (where i is a symbol number and is an integer equal to or greater than 0) 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.

[0420] For example, Figure 11 shows carrier 1 to carrier 5 and time $4 to time $6 extracted from the frame in Figure 4. As in Figure 4, 401 is a pilot symbol, 402 is a data symbol, and 403 is other symbols.

[0421] As described above, in the symbols shown in FIG. 11, phase change unit 205A applies phase change to the (carrier 1, time $5) data symbol, (carrier 2, time $5) data symbol, (carrier 3, time $5) data symbol, (carrier 4, time $5) data symbol, (carrier 5, time $5) data symbol, (carrier 1, time $6) data symbol, (carrier 2, time $6) data symbol, (carrier 4, time $6) data symbol, and (carrier 5, time $6) data symbol.

[0422] Therefore, in the symbols shown in FIG. 11, the phase change value of the data symbol (carrier 1, time $5) is set as "e j×λ15(i) " and the phase change value of the data symbol (carrier 2, time $5) is "e j×λ25(i) " and the phase change value of the data symbol (carrier 3, time $5) is "e j×λ35(i) " and the phase change value of the data symbol (carrier 4, time $5) is "e j×λ45(i) " and the phase change value of the data symbol (carrier 5, time $5) is "e j×λ55(i) " and the phase change value of the data symbol (carrier 1, time $6) is "e j×λ16(i) " and the phase change value of the data symbol (carrier 2, time $6) is "e j×λ26(i) " and the phase change value of the data symbol (carrier 4, time $6) is "e j×λ46(i) " and the phase change value of the data symbol (carrier 5, time $6) is "e j×λ56(i) "

[0423] On the other hand, in the symbols shown in Figure 11, other symbols of (carrier 1, time $4), other symbols of (carrier 2, time $4), other symbols of (carrier 3, time $4), other symbols of (carrier 4, time $4), other symbols of (carrier 5, time $4), and pilot symbols of (carrier 3, time $6) are not subject to phase modification by phase modification unit 205A.

[0424] This is a characteristic feature of phase changer 205A. Note that, as shown in Fig. 4, data carriers are arranged at the "same carrier, same time" as the (carrier 1, time $5) data symbol, (carrier 2, time $5) data symbol, (carrier 3, time $5) data symbol, (carrier 4, time $5) data symbol, (carrier 5, time $5) data symbol, (carrier 1, time $6) data symbol, (carrier 2, time $6) data symbol, (carrier 4, time $6) data symbol, and (carrier 5, time $6) data symbol, which are the targets of phase change in Fig. 11. 4, (carrier 1, time $5) is a data symbol, (carrier 2, time $5) is a data symbol, (carrier 3, time $5) is a data symbol, (carrier 4, time $5) is a data symbol, (carrier 5, time $5) is a data symbol, (carrier 1, time $6) is a data symbol, (carrier 2, time $6) is a data symbol, (carrier 4, time $6) is a data symbol, and (carrier 5, time $6) is a data symbol. (In other words, data symbols undergoing MIMO transmission (transmitting multiple streams) are the targets of phase modification by phase modification section 205A.)

[0425] An example of the phase change that phase change unit 205A applies to the data symbols is a method of performing regular phase change (phase change period N) on the data symbols as shown in equation (50). (However, the method of phase change applied to the data symbols is not limited to this.)

[0426] For example, Figure 11 shows carrier 1 to carrier 5 and time $4 to time $6 extracted from the frame in Figure 5. As in Figure 5, 501 is a pilot symbol, 502 is a data symbol, and 503 is other symbols.

[0427] As described above, in the symbols shown in FIG. 11, phase change unit 205B applies phase change to the (carrier 1, time $5) data symbol, (carrier 2, time $5) data symbol, (carrier 3, time $5) data symbol, (carrier 4, time $5) data symbol, (carrier 5, time $5) data symbol, (carrier 1, time $6) data symbol, (carrier 2, time $6) data symbol, (carrier 4, time $6) data symbol, and (carrier 5, time $6) data symbol.

[0428] Therefore, in the symbols shown in FIG. 11, the phase change value of the data symbol (carrier 1, time $5) is set as "e j×δ15(i) " and the phase change value of the data symbol (carrier 2, time $5) is "e j×δ25(i) " and the phase change value of the data symbol (carrier 3, time $5) is "e j×δ35(i) " and the phase change value of the data symbol (carrier 4, time $5) is "e j×δ45(i) " and the phase change value of the data symbol (carrier 5, time $5) is "e j×δ55(i) " and the phase change value of the data symbol (carrier 1, time $6) is "e j×δ16(i) " and the phase change value of the data symbol (carrier 2, time $6) is "e j×δ26(i) " and the phase change value of the data symbol (carrier 4, time $6) is "e j×δ46(i) " and the phase change value of the data symbol (carrier 5, time $6) is "e j×δ56(i) "

[0429] On the other hand, in the symbols shown in Figure 11, other symbols of (carrier 1, time $4), other symbols of (carrier 2, time $4), other symbols of (carrier 3, time $4), other symbols of (carrier 4, time $4), other symbols of (carrier 5, time $4), and pilot symbols of (carrier 3, time $6) are not subject to phase modification by phase modification unit 205B.

[0430] This is a characteristic feature of phase changer 205B. Note that, as shown in Fig. 4, data carriers are arranged at the "same carrier, same time" as the (carrier 1, time $5) data symbol, (carrier 2, time $5) data symbol, (carrier 3, time $5) data symbol, (carrier 4, time $5) data symbol, (carrier 5, time $5) data symbol, (carrier 1, time $6) data symbol, (carrier 2, time $6) data symbol, (carrier 4, time $6) data symbol, and (carrier 5, time $6) data symbol, which are the targets of phase change in Fig. 11. 4, (carrier 1, time $5) is a data symbol, (carrier 2, time $5) is a data symbol, (carrier 3, time $5) is a data symbol, (carrier 4, time $5) is a data symbol, (carrier 5, time $5) is a data symbol, (carrier 1, time $6) is a data symbol, (carrier 2, time $6) is a data symbol, (carrier 4, time $6) is a data symbol, and (carrier 5, time $6) is a data symbol. (In other words, data symbols undergoing MIMO transmission (transmitting multiple streams) are the targets of phase modification by phase modification section 205B.)

[0431] An example of the phase change that phase change unit 205B applies to the data symbols is a method of performing regular phase change (phase change period N) on the data symbols as shown in equation (2). (However, the method of phase change applied to the data symbols is not limited to this.)

[0432] By doing so, in an environment where direct waves are dominant, particularly in an LOS environment, it is possible to obtain the effect of improving the reception quality of data at a receiving device for data symbols undergoing MIMO transmission (transmitting multiple streams). This effect will now be explained.

[0433] For example, assume that the modulation scheme used in mapping section 104 in FIG. 1 is QPSK (Quadrature Phase Shift Keying). (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.) Then, signal processing section 811 in FIG. 8 uses, for example, channel estimation signals 806_1 and 806_2 to obtain 16 candidate signal points. (QPSK can transmit 2 bits, and a total of 4 bits are transmitted using 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.)

[0434] An example of this state is shown in Figure 12. In both Figures 12(A) and 12(B), 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. (Of the 16 candidate signal points, one is the signal point transmitted by the transmitting device. For this reason, they are called "16 candidate signal points.")

[0435] In an environment where direct waves are dominant, especially in an LOS environment, First case: When the phase change units 205A and 205B of FIG. 20 are not present (that is, when the phase change units 205A and 205B of FIG. 20 are not used for phase change) Think about it.

[0436] In the "first case," no phase change is performed, which may result in a state like that shown in (A) of Fig. 12. If the state shown in (A) of Fig. 12 occurs, there will be areas where signal points are dense (signal points are close together), such as "signal points 1201 and 1202," "signal points 1203, 1204, 1205, 1206," and "signal points 1207, 1208," which may result in a decrease in data reception quality in the receiving device of Fig. 8.

[0437] To overcome this problem, phase shifters 205A and 205B are inserted in Fig. 20. When phase shifters 205A and 205B are inserted, the symbol number i will contain a mixture of symbol numbers where signal points are dense (the distance between signal points is short) as in Fig. 12(A) and symbol numbers where the distance between signal points is long as shown in Fig. 12(B). In this situation, error correction coding is introduced, making it possible to obtain high error correction capability, and thus high data reception quality can be obtained in the receiving device of Fig. 8.

[0438] 20, phase modification sections 205A and 205B in Fig. 20 do 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 the data symbols, "a mixture of symbol numbers where, depending on symbol number i, there are parts where signal points are dense (the distance between signal points is short) as in Fig. 12(A) and symbol numbers where "the distance between signal points is long" as in Fig. 12(B)."

[0439] However, even if the phase shifters 205A and 205B in FIG. 20 shift the phases of the pilot symbols and preambles used for channel estimation to demodulate (detect) data symbols, there may be cases where the data symbols include a mixture of symbol numbers with dense signal points (close distances between signal points) as shown in FIG. 12(A) and symbol numbers with long distances between signal points as shown in FIG. 12(B). In this case, some conditions must be imposed on the pilot symbols and preambles to shift the phases. For example, a method can be considered in which a different rule is established from the rule for shifting the phases of the data symbols to shift the phases of the pilot symbols and / or preambles. For example, a method can be used in which the phases of the data symbols are shifted regularly with a period N, and the phases of the pilot symbols and / or preambles are shifted regularly with a period M (N and M are integers equal to or greater than 2).

[0440] 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 (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)×x'(i) (j is the imaginary unit). The operation of phase changer 209B may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209B is characterized in that it performs phase change on symbols present in the frequency axis direction (it 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.)). (In the case of FIG. 20, phase changer 209B performs phase change on baseband signal 208B, and therefore performs phase change on each symbol shown in FIG. 5.)

[0441] Therefore, in the frame of FIG. 5, phase change section 209B of FIG. 20 applies phase change to all symbols from carrier 1 to carrier 36 at time $1 (in this case, all are other symbols 503).

[0442] Similarly, "Phase change unit 209B in FIG. 20 applies phase change to all symbols from carrier 1 to carrier 36 at time $2 (in this case, all are other symbols 503)." "Phase change unit 209B in FIG. 20 applies phase change to all symbols from carrier 1 to carrier 36 at time $3 (in this case, all are other symbols 503)." "Phase change unit 209B in FIG. 20 applies phase change to all symbols from carrier 1 to carrier 36 at time $4 (in this case, all are other symbols 503)." "Phase change section 209B in FIG. 20 performs phase change on all symbols from carrier 1 to carrier 36 at time $5 (in this case, pilot symbol 501 or data symbol 502)." "Phase change section 209B in FIG. 20 performs phase change on all symbols from carrier 1 to carrier 36 at time $6 (in this case, pilot symbol 501 or data symbol 502)." "Phase change section 209B in FIG. 20 performs phase change on all symbols from carrier 1 to carrier 36 at time $7 (in this case, pilot symbol 501 or data symbol 502)." "Phase change section 209B in FIG. 20 performs phase change on all symbols from carrier 1 to carrier 36 at time $8 (in this case, pilot symbol 501 or data symbol 502)." "Phase change section 209B in FIG. 20 performs phase change on all symbols from carrier 1 to carrier 36 at time $9 (in this case, pilot symbol 501 or data symbol 502)." "Phase change section 209B in FIG. 20 performs phase change on all symbols from carrier 1 to carrier 36 at time $10 (in this case, pilot symbol 501 or data symbol 502)." "Phase change section 209B in FIG. 20 performs phase change on all symbols from carrier 1 to carrier 36 at time $11 (in this case, pilot symbol 501 or data symbol 502)." ...

[0443] 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.

[0444] 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.

[0445] 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 will be transmitted at the same time and on the same frequency. Note that the frame structures in Figures 13 and 14 are merely examples.

[0446] 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).

[0447] It is assumed that the receiving device will receive the frames of Figures 13 and 14 simultaneously, but it is possible for the receiving device to obtain the data transmitted by the transmitting device even if it receives only the frame of Figure 13 or only the frame of Figure 14.

[0448] 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)×x′(i) (j is an imaginary unit). The operation of the phase changer 209B may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Documents 2 and 3. Phase modification unit 209B is characterized in that it performs a phase modification on symbols existing in the frequency axis direction (phase modifications are performed on data symbols, pilot symbols, control information symbols, etc. At this time, null symbols can also be considered to be targets of phase modification. (Accordingly, in this case, the symbols targeted by symbol number i are data symbols, pilot symbols, control information symbols, preambles (other symbols), null symbols, etc.). However, even if a phase modification is performed on a null symbol, the signal before and after the phase modification are the same (in-phase component I is zero (0), and quadrature component Q is zero (0)). Therefore, it is also possible to interpret null symbols as not being targets of phase modification. (In the case of FIG. 20, phase modification unit 209B performs a phase modification on baseband signal 208B, and therefore performs a phase modification on each symbol shown in FIG. 14.)

[0449] Therefore, in the frame of Fig. 14, phase change section 209B of Fig. 20 applies phase change to all symbols from carrier 1 to carrier 36 at time $1 (in this case, all are other symbols 503). However, the handling of phase change for null symbol 1301 is as explained above.

[0450] Similarly, "For all symbols from carrier 1 to carrier 36 at time $2 (in this case, all are other symbols 503), phase change unit 209B in FIG. 20 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $3 (in this case, all are other symbols 503), phase change unit 209B in FIG. 20 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $4 (in this case, all are other symbols 503), phase change unit 209B in FIG. 20 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols of carrier 1 to carrier 36 at time $5 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 20 applies phase change. However, handling of phase change of null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $6 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 20 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $7 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 20 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $8 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 20 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $9 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 20 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $10 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 20 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $11 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 20 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." ...

[0451] 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.

[0452] 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 the imaginary unit) However, equation (38) is merely an example and is not limited to this.

[0453] For example, Ω(i) may be set to perform a phase change with a period Q.

[0454] 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. For carrier 4 in Figures 5 and 14, the phase change value is set to equation (42) regardless of time. ...

[0455] The above is an example of the operation of the phase changer 209B in FIG.

[0456] The effect obtained by the phase changer 209B in FIG. 20 will be described.

[0457] It is assumed that the other symbols 403, 503 in the "frames of Figs. 4 and 5" or "frames of Figs. 13 and 14" contain control information symbols. As explained above, if the other symbols 503 in Fig. 5, which are transmitted at the same time and on the same frequency (same carrier) as the other symbols 403, transmit control information, they transmit the same data (same control information).

[0458] Now, consider the following case.

[0459] Case 2: The control information symbols are transmitted using either antenna unit #A (109_A) or antenna unit #B (109_B) in FIG.

[0460] When transmitting as in "Case 2," the number of antennas transmitting 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)."

[0461] Case 3: Control information symbols are transmitted using both antenna unit #A (109_A) and antenna unit #B (109_B) in Fig. 1. However, no phase change is performed in phase change unit 209B in Fig. 20.

[0462] 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 there is 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 poses a problem in that the receiving device in Figure 8 may experience a decrease in data reception quality.

[0463] To alleviate this problem, 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 will be 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 will be obtained, thereby improving the data reception quality in the receiving device of Fig. 8.

[0464] For the above reasons, in FIG. 20, a phase change section 209B is provided to change the phase.

[0465] 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 (symbols for estimating propagation path fluctuations) for demodulating and decoding 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.

[0466] 4 and 5 or the frames of FIGS. 13 and 14, multiple streams are transmitted (MIMO transmission is performed) using the same frequency (band) and the same time using data symbols 402 and data symbols 502. To demodulate these data symbols, other symbols 403 and other symbols 503 are used, including symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation (symbols for estimating propagation path fluctuations).

[0467] At this time, as mentioned above, the phases of "symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation (symbols for estimating propagation path fluctuations) included in other symbols 403 and other symbols 503" are changed by phase change unit 209B.

[0468] Under such circumstances, if this processing is not reflected on data symbol 402 and data symbol 502 (in 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 (symbols for estimating propagation path fluctuations) included in other symbols 403 and other symbols 503" have been changed by phase change unit 209B.)

[0469] However, as shown in FIG. 20, when phase change section 209B performs a phase change on data symbol 402 and data symbol 502 (on data symbol 502 in the above explanation), the receiving device has the advantage of being able to (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 (symbols for estimating propagation path fluctuation)."

[0470] In addition, as shown in FIG. 20, when phase change section 209B applies a phase change to data symbol 402 and data symbol 502 (in the above-described case, to 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.

[0471] 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.

[0472] As described above, by performing 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, particularly in an LOS environment, and by performing 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.

[0473] 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, particularly 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.

[0474] 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.

[0475] (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.

[0476] 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.

[0477] 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.

[0478] 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 (corresponding to mapped signal 105_1 in FIG. 1), mapped signal 201B (corresponding to mapped signal 105_2 in FIG. 1), and control signal 200 (corresponding to control signal 100 in FIG. 1), performs pre-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 is, for example, time. (s1(t), s2(t), z1'(t), z2'(t) are defined as complex numbers (therefore, they may be real numbers).)

[0479] Here, it is treated as a function of time, but it may be a function of "frequency (carrier number)", or a function of "time-frequency". It may also be a function of "symbol number". This is also the case in the first embodiment.

[0480] The weighting and combining unit (precoding unit) 203 performs the calculation of equation (49).

[0481] 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), where z1(t) is defined as a complex number (it may also be a real number).

[0482] 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). (i is the symbol number (i is an integer equal to or greater than 0))

[0483] For example, the phase change value is set as shown in equation (50).

[0484] (M is an integer of 2 or more, and M is the period of phase change.) (If M is set to an odd number of 3 or more, 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 will be expressed as:

[0485] 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 (or may be a real number).

[0486] 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). (i is the symbol number (i is an integer equal to or greater than 0))

[0487] 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) (Setting N to an odd number equal to or greater than 3 may improve the data reception quality.) 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 will be expressed as:

[0488] In this case, z1(i) and z2(i) can be expressed by equation (51).

[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 (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.

[0490] As explained in the first embodiment, the (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).)

[0491] Insertion section 207A receives weighted combined signal 204A, pilot symbol signal (pa(t)) (t: time) (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.

[0492] Similarly, insertion unit 207B receives phase-changed 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 (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) × x'(i) (j is the imaginary unit).

[0494] As described in the first embodiment and the like, the operation of phase changer 209B may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209B is characterized in that it performs phase change on symbols present in the frequency axis direction (applying phase change to 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 will be 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." Therefore, if other symbols 503 in Figure 5, which are transmitted at the same time and on the same frequency (same carrier) as other symbols 403 in Figure 4, are transmitting control information, they are transmitting the same data (same control information).

[0500] It is assumed that the receiving device will receive the frames of Figures 4 and 5 simultaneously, but it is possible for the receiving device to obtain the data transmitted by the transmitting device even if it receives only the frame of Figure 4 or only the frame of 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] Figure 7 shows an example of the configuration of antenna unit #A (109_A) and antenna unit #B (109_B) in Figure 1 (an example in which antenna unit #A (109_A) and antenna unit #B (109_B) are configured with multiple antennas), and since a detailed explanation has been given in embodiment 1, a detailed 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. (This is 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.

[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 209B as shown in Fig. 21. 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) (where i is a symbol number and is an integer equal to or greater than 0) 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.

[0507] For example, Figure 11 shows carrier 1 to carrier 5 and time $4 to time $6 extracted from the frame in Figure 4. As in Figure 4, 401 is a pilot symbol, 402 is a data symbol, and 403 is other symbols.

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

[0509] Therefore, in the symbols shown in FIG. 11, the phase change value of the data symbol (carrier 1, time $5) is set as "e j×λ15(i) " and the phase change value of the data symbol (carrier 2, time $5) is "e j×λ25(i) " and the phase change value of the data symbol (carrier 3, time $5) is "e j×λ35(i) " and the phase change value of the data symbol (carrier 4, time $5) is "e j×λ45(i)" and the phase change value of the data symbol (carrier 5, time $5) is "e j×λ55(i) " and the phase change value of the data symbol (carrier 1, time $6) is "e j×λ16(i) " and the phase change value of the data symbol (carrier 2, time $6) is "e j×λ26(i) " and the phase change value of the data symbol (carrier 4, time $6) is "e j×λ46(i) " and the phase change value of the data symbol (carrier 5, time $6) is "e j×λ56(i) "

[0510] On the other hand, in the symbols shown in Figure 11, other symbols of (carrier 1, time $4), other symbols of (carrier 2, time $4), other symbols of (carrier 3, time $4), other symbols of (carrier 4, time $4), other symbols of (carrier 5, time $4), and pilot symbols of (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 arranged at the "same carrier, same time" as the (carrier 1, time $5) data symbol, (carrier 2, time $5) data symbol, (carrier 3, time $5) data symbol, (carrier 4, time $5) data symbol, (carrier 5, time $5) data symbol, (carrier 1, time $6) data symbol, (carrier 2, time $6) data symbol, (carrier 4, time $6) data symbol, and (carrier 5, time $6) data symbol, which are the targets of phase change in Fig. 11. 4, (carrier 1, time $5) is a data symbol, (carrier 2, time $5) is a data symbol, (carrier 3, time $5) is a data symbol, (carrier 4, time $5) is a data symbol, (carrier 5, time $5) is a data symbol, (carrier 1, time $6) is a data symbol, (carrier 2, time $6) is a data symbol, (carrier 4, time $6) is a data symbol, and (carrier 5, time $6) is a data symbol. (In other words, data symbols undergoing MIMO transmission (transmitting multiple streams) are the targets of phase modification by phase modification section 205A.)

[0512] An example of the phase change that phase change unit 205A applies to the data symbols is a method of performing regular phase change (phase change period N) on the data symbols as shown in equation (50). (However, the method of phase change applied to the data symbols is not limited to this.)

[0513] For example, Figure 11 shows carrier 1 to carrier 5 and time $4 to time $6 extracted from the frame in Figure 5. As in Figure 5, 501 is a pilot symbol, 502 is a data symbol, and 503 is other symbols.

[0514] As described above, in the symbols shown in FIG. 11, phase change unit 205B applies phase change to the (carrier 1, time $5) data symbol, (carrier 2, time $5) data symbol, (carrier 3, time $5) data symbol, (carrier 4, time $5) data symbol, (carrier 5, time $5) data symbol, (carrier 1, time $6) data symbol, (carrier 2, time $6) data symbol, (carrier 4, time $6) data symbol, and (carrier 5, time $6) data symbol.

[0515] Therefore, in the symbols shown in FIG. 11, the phase change value of the data symbol (carrier 1, time $5) is set as "e j×δ15(i) " and the phase change value of the data symbol (carrier 2, time $5) is "e j×δ25(i) " and the phase change value of the data symbol (carrier 3, time $5) is "e j×δ35(i) " and the phase change value of the data symbol (carrier 4, time $5) is "e j×δ45(i) " and the phase change value of the data symbol (carrier 5, time $5) is "e j×δ55(i) " and the phase change value of the data symbol (carrier 1, time $6) is "e j×δ16(i) " and the phase change value of the data symbol (carrier 2, time $6) is "e j×δ26(i) " and the phase change value of the data symbol (carrier 4, time $6) is "e j×δ46(i) " and the phase change value of the data symbol (carrier 5, time $6) is "e j×δ56(i) "

[0516] On the other hand, in the symbols shown in Figure 11, other symbols of (carrier 1, time $4), other symbols of (carrier 2, time $4), other symbols of (carrier 3, time $4), other symbols of (carrier 4, time $4), other symbols of (carrier 5, time $4), and pilot symbols of (carrier 3, time $6) are not subject to phase modification by phase modification unit 205B.

[0517] This is a characteristic feature of phase changer 205B. Note that, as shown in Fig. 4, data carriers are arranged at the "same carrier, same time" as the (carrier 1, time $5) data symbol, (carrier 2, time $5) data symbol, (carrier 3, time $5) data symbol, (carrier 4, time $5) data symbol, (carrier 5, time $5) data symbol, (carrier 1, time $6) data symbol, (carrier 2, time $6) data symbol, (carrier 4, time $6) data symbol, and (carrier 5, time $6) data symbol, which are the targets of phase change in Fig. 11. 4, (carrier 1, time $5) is a data symbol, (carrier 2, time $5) is a data symbol, (carrier 3, time $5) is a data symbol, (carrier 4, time $5) is a data symbol, (carrier 5, time $5) is a data symbol, (carrier 1, time $6) is a data symbol, (carrier 2, time $6) is a data symbol, (carrier 4, time $6) is a data symbol, and (carrier 5, time $6) is a data symbol. (In other words, data symbols undergoing MIMO transmission (transmitting multiple streams) are the targets of phase modification by phase modification section 205B.)

[0518] An example of the phase change that phase change unit 205B applies to the data symbols is a method of performing regular phase change (phase change period N) on the data symbols as shown in equation (2). (However, the method of phase change applied to the data symbols is not limited to this.)

[0519] By doing so, in an environment where direct waves are dominant, particularly in an LOS environment, it is possible to obtain the effect of improving the reception quality of data at a receiving device for data symbols undergoing MIMO transmission (transmitting multiple streams). This effect will now be explained.

[0520] For example, assume that the modulation scheme used in mapping section 104 in FIG. 1 is QPSK (Quadrature Phase Shift Keying). (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.) Then, signal processing section 811 in FIG. 8 uses, for example, channel estimation signals 806_1 and 806_2 to obtain 16 candidate signal points. (QPSK can transmit 2 bits, and a total of 4 bits are transmitted using 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.)

[0521] An example of this state is shown in Figure 12. In both Figures 12(A) and 12(B), 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. (Of the 16 candidate signal points, one is the signal point transmitted by the transmitting device. For this reason, they are called "16 candidate signal points.")

[0522] In an environment where direct waves are dominant, especially in an LOS environment, First case: When the phase change units 205A and 205B of FIG. 21 are not present (that is, when the phase change units 205A and 205B of FIG. 21 do not perform phase change) Think about it.

[0523] In the "first case," no phase change is performed, which may result in a state like that shown in (A) of Fig. 12. If the state shown in (A) of Fig. 12 occurs, there will be areas where signal points are dense (signal points are close together), such as "signal points 1201 and 1202," "signal points 1203, 1204, 1205, 1206," and "signal points 1207, 1208," which may result in a decrease in data reception quality in the receiving device of Fig. 8.

[0524] To overcome this problem, phase shifters 205A and 205B are inserted in Fig. 21. When phase shifters 205A and 205B are inserted, the symbol number i will contain a mixture of symbol numbers where signal points are dense (the distance between signal points is short) as shown in Fig. 12(A) and symbol numbers where the distance between signal points is long as shown in Fig. 12(B). To address this situation, error correction coding is introduced, making it possible to obtain high error correction capability, and high data reception quality can be achieved in the receiving device of Fig. 8.

[0525] 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 the data symbols, "a mixture of symbol numbers where, depending on symbol number i, there are parts where signal points are dense (the distance between signal points is short) as in Fig. 12(A) and symbol numbers where "the distance between signal points is long" as in Fig. 12(B)."

[0526] However, even if the phase shifters 205A and 205B in FIG. 21 shift the phases of the pilot symbols and preambles used for channel estimation to demodulate (detect) data symbols, there may be cases where the data symbols include a mixture of symbol numbers with dense signal points (close distances between signal points) as shown in FIG. 12(A) and symbol numbers with long distances between signal points as shown in FIG. 12(B). In this case, some conditions must be imposed on the pilot symbols and preambles to shift the phases. For example, a method can be considered in which a different rule is established from the rule for shifting the phases of the data symbols to shift the phases of the pilot symbols and / or preambles. For example, a method can be used in which the phases of the data symbols are shifted regularly with a period N, and the phases of the pilot symbols and / or preambles are shifted regularly with a period M (N and M are integers equal to or greater than 2).

[0527] As described above, 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 (i is an integer equal to or greater than 0), expressed as x'(i). Then, phase-changed 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 (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209A is characterized in that it performs phase change on symbols present in the frequency axis direction (it 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.)). (In the case of FIG. 21, phase changer 209A performs phase change on baseband signal 208A, and therefore performs phase change on each symbol shown in FIG. 4.)

[0528] Therefore, in the frame of FIG. 4, phase change section 209A of FIG. 21 applies phase change to all symbols from carrier 1 to carrier 36 at time $1 (in this case, all are other symbols 403).

[0529] Similarly, "Phase change unit 209A in FIG. 21 applies phase change to all symbols from carrier 1 to carrier 36 at time $2 (in this case, all are other symbols 403)." "Phase change unit 209A in FIG. 21 applies phase change to all symbols from carrier 1 to carrier 36 at time $3 (in this case, all are other symbols 403)." "Phase change unit 209A in FIG. 21 applies phase change to all symbols from carrier 1 to carrier 36 at time $4 (in this case, all are other symbols 403)." "Phase change section 209A in FIG. 21 performs phase change on all symbols from carrier 1 to carrier 36 at time $5 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 21 applies phase change to all symbols from carrier 1 to carrier 36 at time $6 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 21 performs phase change on all symbols from carrier 1 to carrier 36 at time $7 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 21 performs phase change on all symbols from carrier 1 to carrier 36 at time $8 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 21 performs phase change on all symbols from carrier 1 to carrier 36 at time $9 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 21 applies phase change to all symbols from carrier 1 to carrier 36 at time $10 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 21 performs phase change on all symbols from carrier 1 to carrier 36 at time $11 (in this case, pilot symbol 401 or data symbol 402)." ...

[0530] 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.

[0531] 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.

[0532] 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 will be transmitted at the same time and on the same frequency. Note that the frame structures in Figures 13 and 14 are merely examples.

[0533] The other symbols in Figures 13 and 14 are symbols equivalent to "preamble signal 252 and control information symbol signal 253 in Figure 21." Therefore, if other symbol 503 in Figure 14, which is transmitted at the same time and on the same frequency (same carrier) as other symbol 403 in Figure 13, is transmitting control information, it is transmitting the same data (same control information).

[0534] It is assumed that the receiving device will receive the frames of Figures 13 and 14 simultaneously, but it is possible for the receiving device to obtain the data transmitted by the transmitting device even if it receives only the frame of Figure 13 or only the frame of Figure 14.

[0535] 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 (i is an integer equal to or greater than 0), expressed as x'(i). Then, phase-changed signal 210A(x(i)) is expressed as x(i)=e j×ε(i)×x′(i) (j is an imaginary unit). The operation of the phase changer 209A may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Documents 2 and 3. Phase modification unit 209A is characterized in that it performs a phase modification on symbols existing in the frequency axis direction (phase modifications are performed on data symbols, pilot symbols, control information symbols, etc. At this time, null symbols can also be considered to be targets of phase modification. (Accordingly, in this case, the symbols that are targets of symbol number i are data symbols, pilot symbols, control information symbols, preambles (other symbols), null symbols, etc.). However, even if a phase modification is performed on a null symbol, the signal before and after the phase modification are the same (in-phase component I is zero (0), and quadrature component Q is zero (0)). Therefore, it is also possible to interpret that null symbols are not targets of phase modification. (In the case of FIG. 21, phase modification unit 209A performs a phase modification on baseband signal 208A, and therefore performs a phase modification on each symbol shown in FIG. 13.)

[0536] Therefore, in the frame of Fig. 13, phase change section 209A of Fig. 21 applies phase change to all symbols from carrier 1 to carrier 36 at time $1 (in this case, all are other symbols 403). However, the handling of phase change for null symbol 1301 is as explained above.

[0537] Similarly, "For all symbols from carrier 1 to carrier 36 at time $2 (in this case, all are other symbols 403), phase change unit 209A in FIG. 21 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $3 (in this case, all are other symbols 403), phase change unit 209A in FIG. 21 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $4 (in this case, all are other symbols 403), phase change unit 209A in FIG. 21 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $5 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 21 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $6 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 21 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $7 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 21 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $8 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 21 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $9 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 21 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $10 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 21 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $11 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 21 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." ...

[0538] 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.

[0539] 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 the imaginary unit) However, equation (38) is merely an example and is not limited to this.

[0540] For example, Ω(i) may be set to perform a phase change with a period Q.

[0541] 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. For carrier 4 in Figures 4 and 13, the phase change value is set to equation (42) regardless of time. ...

[0542] The above is an example of the operation of the phase changer 209A in FIG.

[0543] The effects obtained by the phase changer 209A in FIG. 21 will be described.

[0544] It is assumed that the other symbols 403, 503 in the "frames of Figs. 4 and 5" or "frames of Figs. 13 and 14" contain control information symbols. As explained above, if the other symbols 503 in Fig. 5, which are transmitted at the same time and on the same frequency (same carrier) as the other symbols 403, transmit control information, they transmit the same data (same control information).

[0545] Now, consider the following case.

[0546] Case 2: The control information symbols are transmitted using either antenna unit #A (109_A) or antenna unit #B (109_B) in FIG.

[0547] When transmitting as in "Case 2," the number of antennas transmitting 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)."

[0548] Case 3: Control information symbols are transmitted using both antenna unit #A (109_A) and antenna unit #B (109_B) in Fig. 1. However, no phase change is performed in phase change unit 209A in Fig. 21.

[0549] 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 there is 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 poses a problem in that the receiving device in Figure 8 may experience a decrease in data reception quality.

[0550] To alleviate this problem, 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 will be 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 will be obtained, which will improve the data reception quality in the receiving device of Fig. 8.

[0551] For the above reasons, in FIG. 21, a phase change section 209A is provided to change the phase.

[0552] 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 (symbols for estimating propagation path fluctuations) for demodulating and decoding 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.

[0553] 4 and 5 or the frames of FIGS. 13 and 14, multiple streams are transmitted (MIMO transmission is performed) using the same frequency (band) and the same time using data symbols 402 and data symbols 502. To demodulate these data symbols, other symbols 403 and other symbols 503 are used, including symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation (symbols for estimating propagation path fluctuations).

[0554] At this time, as mentioned above, the phases of "other symbols 403 and other symbols 503, which are included in the symbols for signal detection, the symbols for frequency synchronization and time synchronization, and the symbols for channel estimation (symbols for estimating propagation path fluctuations)" are changed by phase change unit 209A.

[0555] Under such circumstances, if this processing is not reflected on data symbol 402 and data symbol 502 (in 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. (This is because the phases of "symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation (symbols for estimating propagation path fluctuations) included in other symbols 403 and other symbols 503" have been changed by phase change unit 209A.)

[0556] 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 (symbols for estimating propagation path fluctuation)."

[0557] 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.

[0558] 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.

[0559] As described above, by performing 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, particularly in an LOS environment, and by performing 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.

[0560] 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, particularly 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.

[0561] 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.

[0562] (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.

[0563] 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.

[0564] 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.

[0565] 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 (corresponding to mapped signal 105_1 in FIG. 1), mapped signal 201B (corresponding to mapped signal 105_2 in FIG. 1), and control signal 200 (corresponding to control signal 100 in FIG. 1), performs pre-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 is, for example, time. (s1(t), s2(t), z1'(t), z2'(t) are defined as complex numbers (therefore, they may be real numbers).)

[0566] Here, it is treated as a function of time, but it may be a function of "frequency (carrier number)", or a function of "time-frequency". It may also be a function of "symbol number". This is also the same as in the first embodiment.

[0567] The weighting and combining unit (precoding unit) 203 performs the calculation of equation (49).

[0568] 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), where z1(t) is defined as a complex number (it may also be a real number).

[0569] 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). (i is the symbol number (i is an integer equal to or greater than 0))

[0570] For example, the phase change value is set as shown in equation (50).

[0571] (M is an integer of 2 or more, and M is the period of phase change.) (If M is set to an odd number of 3 or more, 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 will be expressed as:

[0572] 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 (or may be a real number).

[0573] 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). (i is the symbol number (i is an integer equal to or greater than 0))

[0574] 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) (Setting N to an odd number equal to or greater than 3 may improve the data reception quality.) 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 will be expressed as:

[0575] In this case, z1(i) and z2(i) can be expressed by equation (51).

[0576] 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.

[0577] As explained in the first embodiment, the (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).)

[0578] Insertion section 207A receives weighted combined signal 204A, pilot symbol signal (pa(t)) (t: time) (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.

[0579] Similarly, insertion unit 207B receives phase-changed 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.

[0580] 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) × x'(i) (j is the imaginary unit).

[0581] As described in the first embodiment and the like, the operation of phase changer 209B may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209B is characterized in that it performs phase change on symbols present in the frequency axis direction (applying phase change to data symbols, pilot symbols, control information symbols, etc.).

[0582] 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.

[0583] 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.

[0584] 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.

[0585] 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 will be 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.

[0586] The other symbols in Figures 4 and 5 are symbols corresponding to "preamble signal 252 and control information symbol signal 253 in Figure 2." Therefore, if other symbols 503 in Figure 5, which are transmitted at the same time and on the same frequency (same carrier) as other symbols 403 in Figure 4, are transmitting control information, they are transmitting the same data (same control information).

[0587] It is assumed that the receiving device will receive the frames of Figures 4 and 5 simultaneously, but it is possible for the receiving device to obtain the data transmitted by the transmitting device even if it receives only the frame of Figure 4 or only the frame of Figure 5.

[0588] 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.

[0589] Figure 7 shows an example of the configuration of antenna unit #A (109_A) and antenna unit #B (109_B) in Figure 1 (an example in which antenna unit #A (109_A) and antenna unit #B (109_B) are configured with multiple antennas), and since a detailed explanation has been given in embodiment 1, a detailed explanation will be omitted.

[0590] 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.

[0591] Fig. 10 shows an example of the configuration of antenna unit #X (801X) and antenna unit #Y (801Y) in Fig. 8. (This is 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.

[0592] 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.

[0593] As explained using Figures 4 and 5, phase modification units 205A and 205B perform precoding (weighted combining) on mapped signal s1(i) (201A) (where i is a symbol number and is an integer equal to or greater than 0) 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.

[0594] For example, Figure 11 shows carrier 1 to carrier 5 and time $4 to time $6 extracted from the frame in Figure 4. As in Figure 4, 401 is a pilot symbol, 402 is a data symbol, and 403 is other symbols.

[0595] As described above, in the symbols shown in FIG. 11, phase change unit 205A applies phase change to the (carrier 1, time $5) data symbol, (carrier 2, time $5) data symbol, (carrier 3, time $5) data symbol, (carrier 4, time $5) data symbol, (carrier 5, time $5) data symbol, (carrier 1, time $6) data symbol, (carrier 2, time $6) data symbol, (carrier 4, time $6) data symbol, and (carrier 5, time $6) data symbol.

[0596] Therefore, in the symbols shown in FIG. 11, the phase change value of the data symbol (carrier 1, time $5) is set as "e j×λ15(i) " and the phase change value of the data symbol (carrier 2, time $5) is "e j×λ25(i) " and the phase change value of the data symbol (carrier 3, time $5) is "e j×λ35(i) " and the phase change value of the data symbol (carrier 4, time $5) is "e j×λ45(i)" and the phase change value of the data symbol (carrier 5, time $5) is "e j×λ55(i) " and the phase change value of the data symbol (carrier 1, time $6) is "e j×λ16(i) " and the phase change value of the data symbol (carrier 2, time $6) is "e j×λ26(i) " and the phase change value of the data symbol (carrier 4, time $6) is "e j×λ46(i) " and the phase change value of the data symbol (carrier 5, time $6) is "e j×λ56(i) "

[0597] On the other hand, in the symbols shown in Figure 11, other symbols of (carrier 1, time $4), other symbols of (carrier 2, time $4), other symbols of (carrier 3, time $4), other symbols of (carrier 4, time $4), other symbols of (carrier 5, time $4), and pilot symbols of (carrier 3, time $6) are not subject to phase modification by phase modification unit 205A.

[0598] This is a characteristic feature of phase changer 205A. Note that, as shown in Fig. 4, data carriers are arranged at the "same carrier, same time" as the (carrier 1, time $5) data symbol, (carrier 2, time $5) data symbol, (carrier 3, time $5) data symbol, (carrier 4, time $5) data symbol, (carrier 5, time $5) data symbol, (carrier 1, time $6) data symbol, (carrier 2, time $6) data symbol, (carrier 4, time $6) data symbol, and (carrier 5, time $6) data symbol, which are the targets of phase change in Fig. 11. 4, (carrier 1, time $5) is a data symbol, (carrier 2, time $5) is a data symbol, (carrier 3, time $5) is a data symbol, (carrier 4, time $5) is a data symbol, (carrier 5, time $5) is a data symbol, (carrier 1, time $6) is a data symbol, (carrier 2, time $6) is a data symbol, (carrier 4, time $6) is a data symbol, and (carrier 5, time $6) is a data symbol. (In other words, data symbols undergoing MIMO transmission (transmitting multiple streams) are the targets of phase modification by phase modification section 205A.)

[0599] An example of the phase change that phase change unit 205A applies to the data symbols is a method of performing regular phase change (phase change period N) on the data symbols as shown in equation (50). (However, the method of phase change applied to the data symbols is not limited to this.)

[0600] For example, Figure 11 shows carrier 1 to carrier 5 and time $4 to time $6 extracted from the frame in Figure 5. As in Figure 5, 501 is a pilot symbol, 502 is a data symbol, and 503 is other symbols.

[0601] As described above, in the symbols shown in FIG. 11, phase change unit 205B applies phase change to the (carrier 1, time $5) data symbol, (carrier 2, time $5) data symbol, (carrier 3, time $5) data symbol, (carrier 4, time $5) data symbol, (carrier 5, time $5) data symbol, (carrier 1, time $6) data symbol, (carrier 2, time $6) data symbol, (carrier 4, time $6) data symbol, and (carrier 5, time $6) data symbol.

[0602] Therefore, in the symbols shown in FIG. 11, the phase change value of the data symbol (carrier 1, time $5) is set as "e j×δ15(i) " and the phase change value of the data symbol (carrier 2, time $5) is "e j×δ25(i) " and the phase change value of the data symbol (carrier 3, time $5) is "e j×δ35(i) " and the phase change value of the data symbol (carrier 4, time $5) is "e j×δ45(i) " and the phase change value of the data symbol (carrier 5, time $5) is "e j×δ55(i) " and the phase change value of the data symbol (carrier 1, time $6) is "e j×δ16(i) " and the phase change value of the data symbol (carrier 2, time $6) is "e j×δ26(i) " and the phase change value of the data symbol (carrier 4, time $6) is "e j×δ46(i) " and the phase change value of the data symbol (carrier 5, time $6) is "e j×δ56(i) "

[0603] On the other hand, in the symbols shown in Figure 11, other symbols of (carrier 1, time $4), other symbols of (carrier 2, time $4), other symbols of (carrier 3, time $4), other symbols of (carrier 4, time $4), other symbols of (carrier 5, time $4), and pilot symbols of (carrier 3, time $6) are not subject to phase modification by phase modification unit 205B.

[0604] This is a characteristic feature of phase changer 205B. Note that, as shown in Fig. 4, data carriers are arranged at the "same carrier, same time" as the (carrier 1, time $5) data symbol, (carrier 2, time $5) data symbol, (carrier 3, time $5) data symbol, (carrier 4, time $5) data symbol, (carrier 5, time $5) data symbol, (carrier 1, time $6) data symbol, (carrier 2, time $6) data symbol, (carrier 4, time $6) data symbol, and (carrier 5, time $6) data symbol, which are the targets of phase change in Fig. 11. 4, (carrier 1, time $5) is a data symbol, (carrier 2, time $5) is a data symbol, (carrier 3, time $5) is a data symbol, (carrier 4, time $5) is a data symbol, (carrier 5, time $5) is a data symbol, (carrier 1, time $6) is a data symbol, (carrier 2, time $6) is a data symbol, (carrier 4, time $6) is a data symbol, and (carrier 5, time $6) is a data symbol. (In other words, data symbols undergoing MIMO transmission (transmitting multiple streams) are the targets of phase modification by phase modification section 205B.)

[0605] An example of the phase change that phase change unit 205B applies to the data symbols is a method of performing regular phase change (phase change period N) on the data symbols as shown in equation (2). (However, the method of phase change applied to the data symbols is not limited to this.)

[0606] By doing so, in an environment where direct waves are dominant, particularly in an LOS environment, it is possible to obtain the effect of improving the reception quality of data at a receiving device for data symbols undergoing MIMO transmission (transmitting multiple streams). This effect will now be explained.

[0607] For example, assume that the modulation scheme used in mapping section 104 in FIG. 1 is QPSK (Quadrature Phase Shift Keying). (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.) Then, signal processing section 811 in FIG. 8 uses, for example, channel estimation signals 806_1 and 806_2 to obtain 16 candidate signal points. (QPSK can transmit 2 bits, and a total of 4 bits are transmitted using 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.)

[0608] An example of this state is shown in Figure 12. In both Figures 12(A) and 12(B), 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. (Of the 16 candidate signal points, one is the signal point transmitted by the transmitting device. For this reason, they are called "16 candidate signal points.")

[0609] In an environment where direct waves are dominant, especially in an LOS environment, First case: When the phase change units 205A and 205B of FIG. 22 are not present (that is, when the phase change units 205A and 205B of FIG. 22 are not used for phase change) Think about it.

[0610] In the "first case," no phase change is performed, which may result in a state like that shown in (A) of Fig. 12. If the state shown in (A) of Fig. 12 occurs, there will be areas where signal points are dense (signal points are close together), such as "signal points 1201 and 1202," "signal points 1203, 1204, 1205, 1206," and "signal points 1207, 1208," which may result in a decrease in data reception quality in the receiving device of Fig. 8.

[0611] To overcome this problem, phase shifters 205A and 205B are inserted in Fig. 22. When phase shifters 205A and 205B are inserted, the symbol number i will contain a mixture of symbol numbers where signal points are dense (the distance between signal points is short) as in Fig. 12(A) and symbol numbers where the distance between signal points is long as shown in Fig. 12(B). In response to this situation, an error correction code is introduced, making it possible to obtain high error correction capability, and thus high data reception quality can be obtained in the receiving device of Fig. 8.

[0612] In Fig. 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 the data symbols, "a mixture of symbol numbers where, depending on symbol number i, there are parts where signal points are dense (the distance between signal points is short) as in Fig. 12(A) and symbol numbers where "the distance between signal points is long" as in Fig. 12(B)."

[0613] However, even if the phase shifters 205A and 205B in FIG. 22 shift the phases of the pilot symbols and preambles used for channel estimation to demodulate (detect) data symbols, there may be cases where the data symbols contain a mixture of symbol numbers with dense signal points (close distances between signal points) as shown in FIG. 12(A) and symbol numbers with long distances between signal points as shown in FIG. 12(B). In this case, some conditions must be imposed on the pilot symbols and preambles to shift the phases. For example, a method can be considered in which a separate rule is established for shifting the phases of the pilot symbols and / or preambles. For example, a method can be used in which the phase shift is regularly performed on the data symbols with a period N, and the phase shift is regularly performed on the pilot symbols and / or preambles with a period M (N and M are integers equal to or greater than 2).

[0614] As described above, 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 (i is an integer equal to or greater than 0), expressed as x'(i). Then, phase-changed 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 (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209A is characterized in that it performs phase change on symbols present in the frequency axis direction (it 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.)). (In the case of FIG. 22, phase changer 209A performs phase change on baseband signal 208A, and therefore performs phase change on each symbol shown in FIG. 4.)

[0615] Therefore, in the frame of FIG. 4, phase change section 209A of FIG. 22 applies phase change to all symbols from carrier 1 to carrier 36 at time $1 (in this case, all are other symbols 403).

[0616] Similarly, "Phase change unit 209A in FIG. 22 applies phase change to all symbols from carrier 1 to carrier 36 at time $2 (in this case, all are other symbols 403)." "Phase change unit 209A in FIG. 22 applies phase change to all symbols from carrier 1 to carrier 36 at time $3 (in this case, all are other symbols 403)." "Phase change unit 209A in FIG. 22 applies phase change to all symbols from carrier 1 to carrier 36 at time $4 (in this case, all are other symbols 403)." "Phase change section 209A in FIG. 22 performs phase change on all symbols from carrier 1 to carrier 36 at time $5 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 22 performs phase change on all symbols from carrier 1 to carrier 36 at time $6 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 22 performs phase change on all symbols from carrier 1 to carrier 36 at time $7 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 22 performs phase change on all symbols from carrier 1 to carrier 36 at time $8 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 22 performs phase change on all symbols from carrier 1 to carrier 36 at time $9 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 22 applies phase change to all symbols from carrier 1 to carrier 36 at time $10 (in this case, pilot symbol 401 or data symbol 402)." "Phase change section 209A in FIG. 22 performs phase change on all symbols from carrier 1 to carrier 36 at time $11 (in this case, pilot symbol 401 or data symbol 402)." ...

[0617] 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 (i is an integer equal to or greater than 0), expressed as y'(i). Then, phase-changed signal 210B(y(i)) is expressed as y(i)=e j×η(i)×y'(i) (j is the imaginary unit). The operation of phase changer 209B may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Document 2 and Non-Patent Document 3. Phase changer 209B is characterized in that it performs phase change on symbols present in the frequency axis direction (it 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.)). (In the case of FIG. 22, phase changer 209B performs phase change on baseband signal 208B, and therefore performs phase change on each symbol shown in FIG. 5.)

[0618] Therefore, in the frame of FIG. 5, phase change section 209B of FIG. 22 applies phase change to all symbols from carrier 1 to carrier 36 at time $1 (in this case, all are other symbols 503).

[0619] Similarly, "Phase change unit 209B in FIG. 22 applies phase change to all symbols from carrier 1 to carrier 36 at time $2 (in this case, all are other symbols 503)." "Phase change unit 209B in FIG. 22 applies phase change to all symbols from carrier 1 to carrier 36 at time $3 (in this case, all are other symbols 503)." "Phase change unit 209B in FIG. 22 applies phase change to all symbols from carrier 1 to carrier 36 at time $4 (in this case, all are other symbols 503)." "Phase change section 209B in FIG. 22 applies phase change to all symbols from carrier 1 to carrier 36 at time $5 (in this case, pilot symbol 501 or data symbol 502)." "Phase change section 209B in FIG. 22 performs phase change on all symbols from carrier 1 to carrier 36 at time $6 (in this case, pilot symbol 501 or data symbol 502)." "Phase change section 209B in FIG. 22 performs phase change on all symbols from carrier 1 to carrier 36 at time $7 (in this case, pilot symbol 501 or data symbol 502)." "Phase change section 209B in FIG. 22 performs phase change on all symbols from carrier 1 to carrier 36 at time $8 (in this case, pilot symbol 501 or data symbol 502)." "Phase change section 209B in FIG. 22 performs phase change on all symbols from carrier 1 to carrier 36 at time $9 (in this case, pilot symbol 501 or data symbol 502)." "Phase change section 209B in FIG. 22 performs phase change on all symbols from carrier 1 to carrier 36 at time $10 (in this case, pilot symbol 501 or data symbol 502)." "Phase change section 209B in FIG. 22 performs phase change on all symbols from carrier 1 to carrier 36 at time $11 (in this case, pilot symbol 501 or data symbol 502)." ...

[0620] 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.

[0621] 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.

[0622] 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 will be transmitted at the same time and on the same frequency. Note that the frame structures in Figures 13 and 14 are merely examples.

[0623] The other symbols in Figures 13 and 14 are symbols equivalent to "preamble signal 252 and control information symbol signal 253 in Figure 22." Therefore, if other symbol 503 in Figure 14, which is transmitted at the same time and on the same frequency (same carrier) as other symbol 403 in Figure 13, is transmitting control information, it is transmitting the same data (same control information).

[0624] It is assumed that the receiving device will receive the frames of Figures 13 and 14 simultaneously, but it is possible for the receiving device to obtain the data transmitted by the transmitting device even if it receives only the frame of Figure 13 or only the frame of Figure 14.

[0625] 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 (i is an integer equal to or greater than 0), expressed as x'(i). Then, phase-changed signal 210A(x(i)) is expressed as x(i)=e j×ε(i)×x′(i) (j is an imaginary unit). The operation of the phase changer 209A may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Documents 2 and 3. Phase modification unit 209A is characterized in that it performs a phase modification on symbols existing in the frequency axis direction (phase modifications are performed on data symbols, pilot symbols, control information symbols, etc. At this time, null symbols can also be considered to be targets of phase modification. (Accordingly, in this case, the symbols targeted by symbol number i are data symbols, pilot symbols, control information symbols, preambles (other symbols), null symbols, etc.). However, even if a phase modification is performed on a null symbol, the signal before and after the phase modification are the same (in-phase component I is zero (0), and quadrature component Q is zero (0)). Therefore, it is also possible to interpret null symbols as not being targets of phase modification. (In the case of FIG. 22, phase modification unit 209A performs a phase modification on baseband signal 208A, and therefore performs a phase modification on each symbol shown in FIG. 13.)

[0626] Therefore, in the frame of Fig. 13, phase change section 209A of Fig. 22 applies phase change to all symbols from carrier 1 to carrier 36 at time $1 (in this case, all are other symbols 403). However, the handling of phase change for null symbol 1301 is as explained above.

[0627] Similarly, "For all symbols from carrier 1 to carrier 36 at time $2 (in this case, all are other symbols 403), phase change unit 209A in FIG. 22 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $3 (in this case, all are other symbols 403), phase change unit 209A in FIG. 22 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $4 (in this case, all are other symbols 403), phase change unit 209A in FIG. 22 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $5 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 22 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $6 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 22 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $7 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 22 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $8 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 22 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $9 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 22 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $10 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 22 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $11 (in this case, pilot symbol 401 or data symbol 402), phase change section 209A in FIG. 22 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." ...

[0628] 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.

[0629] 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 the imaginary unit) However, equation (38) is merely an example and is not limited to this.

[0630] For example, Ω(i) may be set to perform a phase change with a period Q.

[0631] 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. For carrier 4 in Figures 4 and 13, the phase change value is set to equation (42) regardless of time. ...

[0632] The above is an example of the operation of the phase changer 209A in FIG.

[0633] 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 y'(i). Then, phase-changed signal 210B(x(i)) is expressed as y(i)=e j×η(i) ×y′(i) (j is an imaginary unit). The operation of the phase changer 209B may be CDD (Cyclic Delay Diversity) (CSD (Cyclic Shift Diversity)) described in Non-Patent Documents 2 and 3. Phase modification unit 209B is characterized in that it performs a phase modification on symbols existing in the frequency axis direction (phase modification is performed on data symbols, pilot symbols, control information symbols, etc. At this time, null symbols can also be considered to be targets of phase modification. (Therefore, in this case, the symbols that are targets of symbol number i are data symbols, pilot symbols, control information symbols, preambles (other symbols), null symbols, etc.). However, even if a phase modification is performed on a null symbol, the signal before and after the phase modification are the same (in-phase component I is zero (0), and quadrature component Q is zero (0)). Therefore, it is also possible to interpret that null symbols are not targets of phase modification. (In the case of FIG. 22, phase modification unit 209B performs a phase modification on baseband signal 208B, and therefore performs a phase modification on each symbol shown in FIG. 14.)

[0634] Therefore, in the frame of Fig. 14, phase change section 209B of Fig. 22 applies phase change to all symbols from carrier 1 to carrier 36 at time $1 (in this case, all are other symbols 503). However, the handling of phase change for null symbol 1301 is as explained above.

[0635] Similarly, "For all symbols from carrier 1 to carrier 36 at time $2 (in this case, all are other symbols 503), phase change unit 209B in FIG. 22 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $3 (in this case, all are other symbols 503), phase change unit 209B in FIG. 22 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $4 (in this case, all are other symbols 503), phase change unit 209B in FIG. 22 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $5 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 22 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $6 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 22 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $7 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 22 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $8 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 22 performs phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $9 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 22 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $10 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 22 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." "For all symbols from carrier 1 to carrier 36 at time $11 (in this case, pilot symbol 501 or data symbol 502), phase change section 209B in FIG. 22 applies phase change. However, handling of phase change for null symbol 1301 is as explained above." ...

[0636] 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.

[0637] For example, the phase change value is set as in equation (49). (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.)

[0638] For example, Δ(i) may be set to change the phase to have a period R.

[0639] 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. For carrier 4 in Figures 5 and 14, the phase change value is set to equation (42) regardless of time. ...

[0640] The above is an example of the operation of the phase changer 209B in FIG.

[0641] The effects obtained by the phase change units 209A and 209B in FIG. 22 will be described.

[0642] It is assumed that the other symbols 403, 503 in the "frames of Figs. 4 and 5" or "frames of Figs. 13 and 14" contain control information symbols. As explained above, if the other symbols 503 in Fig. 5, which are transmitted at the same time and on the same frequency (same carrier) as the other symbols 403, transmit control information, they transmit the same data (same control information).

[0643] Now, consider the following case.

[0644] Case 2: The control information symbols are transmitted using either antenna unit #A (109_A) or antenna unit #B (109_B) in FIG.

[0645] When transmitting as in "Case 2," the number of antennas transmitting 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)."

[0646] 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 units 209A and 209B in Fig. 22.

[0647] 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 there is 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 poses a problem in that the receiving device in Figure 8 may experience a decrease in data reception quality.

[0648] To alleviate this problem, phase change units 209A and 209B are provided in Fig. 22. 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 will be 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 will be obtained, thereby improving the data reception quality in the receiving device of Fig. 8.

[0649] For the above reasons, in FIG. 22, phase change sections 209A and 209B are provided to perform phase change.

[0650] 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 (symbols for estimating propagation path fluctuations) for demodulating and decoding 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.

[0651] 4 and 5 or the frames of FIGS. 13 and 14, multiple streams are transmitted (MIMO transmission is performed) using the same frequency (band) and the same time using data symbols 402 and data symbols 502. To demodulate these data symbols, other symbols 403 and other symbols 503 are used, including symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation (symbols for estimating propagation path fluctuations).

[0652] At this time, as mentioned above, the phases of "symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation (symbols for estimating propagation path fluctuations) included in other symbols 403 and other symbols 503" are changed by phase change units 209A and 209B.

[0653] Under such circumstances, if this processing is not reflected on data symbol 402 and data symbol 502 (in 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. (This is because the phases of "symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation (symbols for estimating propagation path fluctuations) included in other symbols 403 and other symbols 503" have been changed by phase change units 209A and 209B.)

[0654] 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 (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 symbols for signal detection, symbols for frequency synchronization and time synchronization, and symbols for channel estimation (symbols for estimating propagation path fluctuation) contained in other symbols 503."

[0655] 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.

[0656] 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.

[0657] 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, particularly 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...

Claims

1. A mapping unit, a signal processing unit, and a transmitting unit, The mapping unit operates by: if the first precoding is enabled, generating a plurality of first symbols by modulating the bit sequence; if the first precoding is not enabled, generating second and third symbols by modulating a bit sequence; The signal processing unit, in operation, If the first precoding is enabled, performing the first precoding on the plurality of first symbols to generate a plurality of first precoded symbols, each of the first precoded symbols being a weighted sum of the plurality of first symbols; if the first precoding is not enabled, performing second precoding on the second symbol and the third symbol to generate a second precoded symbol that is a weighted sum of the second symbol and the third symbol and a third precoded symbol that is a weighted sum of the second symbol and the third symbol; The transmitter, in operation, transmitting the first precoded symbols or the second precoded symbols and the third precoded symbols; each of the plurality of first precoded symbols is mapped to a plurality of subcarriers different from each other; Transmitting device.

2. the transmitter uses an OFDM (orthogonal frequency-division multiplexing) transmission mode; The transmitting device according to claim 1 .

3. The first precoding and the second precoding are the same precoding. based on the matching matrix, The transmitting device according to claim 1 .

4. A transmission method performed by a transmission device, comprising: if the first precoding is enabled, generating a plurality of first symbols by modulating the bit sequence; a first step of generating second and third symbols by modulating a bit sequence if the first precoding is not effective; If the first precoding is enabled, performing the first precoding on the plurality of first symbols to generate a plurality of first precoded symbols, each of the first precoded symbols being a weighted sum of the plurality of first symbols; a second step of performing second precoding on the second symbol and the third symbol when the first precoding is not enabled, to generate a second precoded symbol that is a weighted sum of the second symbol and the third symbol, and a third precoded symbol that is a weighted sum of the second symbol and the third symbol; a third step of transmitting the first precoded symbols or the second precoded symbols and the third precoded symbols; Including, each of the plurality of first precoded symbols is mapped to a plurality of subcarriers different from each other; Sending method.

5. the third step uses an OFDM (orthogonal frequency-division multiplexing) transmission mode; The transmission method according to claim 4.

6. the first precoding and the second precoding are performed based on the same precoding matrix. The transmission method according to claim 4.

Images