Terminal, communication method, and integrated circuit

Abstract

This communication system comprises: a first radio-communication device that transmits a plurality of first reference signals with controlled directivity in a time-sharing manner in a first period; and a second radio-communication device that transmits a plurality of second reference signals with controlled directivity to the first radio-communication device in a time-sharing manner in a second period, the second reference signal including information on directivity corresponding to any one of the first reference signals received from the first radio-communication device.

Description

Technical Field

[0001] The present disclosure relates to a wireless communication system, a wireless communication device, and a wireless communication method.

Background Art

[0002] For example, as a system using a frequency of 52.6 GHz or higher, there is a communication system using the 60 GHz band.

[0003] As a communication method for increasing the communication distance, there is a method described in Patent Document 1. FIG. 63 shows an example of the communication state of a wireless communication device described in Patent Document 1.

[0004] For example, the wireless communication device 001 transmits a sector sweep signal. Thereafter, the wireless communication device 051 transmits a sector sweep signal. Then, the wireless communication device 051 transmits a signal including feedback information regarding the sector sweep to the wireless communication device 001.

[0005] By following this procedure, the wireless communication device 001 determines a method of "transmission beamforming and / or reception beamforming", and the wireless communication device 051 also determines a method of "transmission beamforming and / or reception beamforming". As a result, the communicable distance between the wireless communication device 001 and the wireless communication device 051 can be increased. However, in an environment where a plurality of wireless communication devices exist, there remains a problem regarding improvement of the overall data transmission efficiency of the communication system constituted by the plurality of wireless communication devices.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] Non-limiting embodiments of the present disclosure contribute to providing a technique for improving data transmission speed when there are multiple wireless communication devices.

Means for Solving the Problems

[0008] A wireless communication system according to an aspect of the present disclosure includes: a first wireless communication device that transmits a plurality of first reference signals with controlled directivity in a time-division manner in a first period; and a second wireless communication device that includes information regarding the directivity corresponding to any one of the first reference signals received from the first wireless communication device, and transmits a plurality of second reference signals with controlled directivity to the first wireless communication device in a time-division manner in a second period.

[0009] A wireless communication device according to an aspect of the present disclosure includes: a reception processing unit that receives a plurality of first reference signals with controlled directivity by another wireless communication device in a first period; and a transmission processing unit that includes information regarding the directivity corresponding to any one of the first reference signals, and transmits a plurality of second reference signals with controlled directivity to the other wireless communication device in a time-division manner in a second period.

[0010] A wireless communication device according to an aspect of the present disclosure includes: a transmission processing unit that transmits a plurality of first reference signals with controlled directivity in a time-division manner in a first period; and a reception processing unit that includes information regarding the directivity corresponding to any one of the first reference signals, and receives at least one of a plurality of second reference signals with controlled directivity by another wireless communication device that has received the first reference signal in a second period.

[0011] A wireless communication method according to an aspect of the present disclosure includes a first wireless communication device transmitting a plurality of first reference signals with controlled directivity in a time-division manner during a first period, and a second wireless communication device transmitting a plurality of second reference signals with controlled directivity to the first wireless communication device in a time-division manner during a second period, the plurality of second reference signals including information regarding the directivity corresponding to any one of the first reference signals received from the first wireless communication device.

[0012] These general or specific aspects may be implemented in a system, apparatus, method, integrated circuit, computer program, or recording medium, or may be implemented in any combination of a system, apparatus, method, integrated circuit, computer program, and recording medium.

Advantages of the Invention

[0013] According to a non-limiting example of the present disclosure, the data transmission rate when there are multiple wireless communication devices is improved.

[0014] Further advantages and effects in an aspect of the present disclosure will be apparent from the specification and drawings. Such advantages and / or effects are provided by some embodiments and the features described in the specification and drawings, respectively, but not all of them are necessarily provided to obtain one or more identical features.

Brief Description of the Drawings

[0015]

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Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0017] (Embodiment 1) The communication system, communication device, and communication method of this embodiment will be described in detail.

[0018] FIG. 1A shows an example of the configuration of a communication device such as a base station, access point, terminal, repeater, etc. in this embodiment.

[0019] The communication device in FIG. 1A is assumed to include N transmission units from "first transmission unit 102_1 to Nth transmission unit 102_N". Note that N is an integer of 1 or more or an integer of 2 or more.

[0020] Also, the communication device in FIG. 1A is assumed to include M transmission panel antennas for M transmissions from "transmission panel antenna 1 of 106_1 to transmission panel antenna M of 106_M". Note that M is an integer of 1 or more or an integer of 2 or more.

[0021] The communication device in FIG. 1A is assumed to include n receiving units from "receiving unit 155_1 to receiving unit 155_n". Here, n is an integer of 1 or more or an integer of 2 or more.

[0022] The communication device in FIG. 1A is assumed to include reception panel antennas for reception of m "reception panel antennas 1 of 151_1 to reception panel antennas m of 151_m". Here, m is an integer of 1 or more or an integer of 2 or more.

[0023] The i-th transmission unit 102_i takes the control signal 100 and the i-th data 101_i as inputs, performs processes such as error correction coding and mapping according to the modulation method, and outputs the i-th modulated signal 103_i. Here, i is assumed to be an integer of 1 or more and N or less.

[0024] The first processing unit 104 takes the i-th modulated signal 103_i (where i is an integer of 1 or more and N or less), the control signal 100, and the reference signal 199 as inputs, and outputs the j-th transmission signal 105_j (where j is an integer of 1 or more and M or less) based on the frame configuration information included in the control signal 100. Note that there may be some i-th modulated signals 103_i in which no signal exists, and there may also be some j-th transmission signals 105_j in which no signal exists.

[0025] Then, the j-th transmission signal 105_j is output as a radio wave from the transmission panel antenna j of 106_j. Here, the transmission panel antenna j of 106_j takes the control signal 100 as an input, performs beamforming, and may change the transmission directivity. Also, when transmitting a modulated signal to a communication partner by the control signal 100, the transmission panel antenna j of 106_j may be switched. This will be described later.

[0026] The i-th reception signal 152_i is received by the reception panel antenna i of 151_i. Here, the reception panel antenna i of 151_i takes the control signal 100 as an input, performs beamforming, and may change the reception directivity. This will be described later.

[0027] The second processing unit 153 takes the i-th received signal 152_i and the control signal 100 as inputs, performs processes such as frequency conversion, and outputs the j-th signal after signal processing 154_j. Note that there may be cases where there is no signal in the i-th received signal 152_i, and there may also be cases where there is no signal in the j-th signal after signal processing 154_j.

[0028] The j-th receiving unit 155_j takes the j-th signal after signal processing 154_j and the control signal 100 as inputs, and based on the control signal 100, performs processes such as demodulation and error correction decoding on the j-th signal after signal processing 154, and outputs the j-th control data 156_j and the j-th data 157_j.

[0029] The third processing unit 158 takes the j-th control data 156_j as an input, generates and outputs the control signal 100 based on information obtained from the communication partner, etc.

[0030] Note that the first processing unit 104 of the communication device in FIG. 1A may perform processes for transmission beamforming (transmission directivity control), for example, precoding processes. Also, the second processing unit 153 may perform processes for reception directivity control. As another example, for example, the first processing unit 104 may perform processes such as taking the first transmission signal 105_1 as the first modulation signal 103_1, taking the second transmission signal 105_2 as the second modulation signal 103_2, taking the third transmission signal 105_3 as the third modulation signal 103_3, and outputting them. Alternatively, the first processing unit 104 may perform processes such as taking the first transmission signal 105_1 as the second modulation signal 103_2 and outputting it. Also, the second processing unit 153 may perform processes such as taking the first signal after signal processing 154_1 as the first received signal 152_1, taking the second signal after signal processing 154_2 as the second received signal 152_2, taking the third signal after signal processing 154_3 as the third received signal 152_3, and outputting them. Alternatively, the second processing unit may perform processes such as taking the second signal after signal processing 154_2 as the first received signal 152_1 and outputting it.

[0031] In FIG. 1A, a configuration in which a processing unit not shown in FIG. 1A may be added. For example, an interleaver for rearranging symbols and / or data, a padding unit for padding, etc. may be included in the communication device. Further, the communication device of FIG. 1A may perform transmission and / or reception corresponding to MIMO (Multiple Input Multiple Output) transmission that transmits a plurality of modulation signals (a plurality of streams) using a plurality of antennas.

[0032] FIG. 1B is a different configuration example of a communication device such as a base station, an access point, a terminal, a repeater, etc. in the present embodiment compared to FIG. 1A. In FIG. 1B, those that operate in the same manner as in FIG. 1A are given the same numbers, and detailed descriptions are omitted.

[0033] The characteristic point of FIG. 1B is that the number of transmission units is the same as the number of transmission panel antennas. At this time, the first processing unit 104 may perform processing for transmission beamforming (transmission directivity control), for example, precoding. Also, the first processing unit 104 may use the x-th transmission signal 105_x as the y-th modulation signal 103_y and output it. Here, x is an integer of 1 or more and M or less, and y is an integer of 1 or more and M or less.

[0034] And it is assumed that the number of reception units is the same as the number of reception panel antennas. At this time, the second processing unit 153 may perform processing for reception directivity control. Also, the second processing unit 153 may use the signal 154_x after the x-th signal processing as the y-th reception signal 152_y and output it. Here, x is an integer of 1 or more and m or less, and y is an integer of 1 or more and m or less.

[0035] FIG. 1C is a different configuration example of a communication device such as a base station, an access point, a terminal, a repeater, etc. in the present embodiment compared to FIGS. 1A and 1B. In FIG. 1C, those that operate in the same manner as in FIG. 1A are given the same numbers, and detailed descriptions are omitted.

[0036] The characteristic points of FIG. 1C are that the number of transmission units is the same as the number of transmission panel antennas, and there is no first processing unit. Also, the number of reception units is the same as the number of reception panel antennas, and there is no second processing unit.

[0037] FIG. 2 shows a configuration example of the i-th transmission unit 102_i. Here, i is an integer of "1 or more and N or less" or "1 or more and M or less".

[0038] The data symbol generation unit 202 takes the data 201 and the control signal 200 as inputs, and based on the information such as the error correction coding method information, modulation method information, transmission method information, and frame configuration method included in the control signal 200, performs error correction coding, mapping, signal processing for transmission, etc., and outputs a modulation signal 203 of the data symbol. Here, the data 201 corresponds to the i-th data 101_i, and the control signal 200 corresponds to the control signal 100.

[0039] The sector sweep reference signal generation unit 204 takes the control signal 200 as an input, and based on the frame configuration information included in the control signal 200, generates and outputs a sector sweep reference signal 205.

[0040] The other signal generation unit 206 takes the control signal 200 as an input, and based on the control signal, generates and outputs another signal 207.

[0041] The processing unit 251 takes the modulation signal 203 of the data symbol, the sector sweep reference signal 205, the other signal 207, and the control signal 200 as inputs, and based on the frame configuration information included in the control signal 200, generates and outputs a modulation signal 252 according to the frame configuration. Here, the modulation signal 252 according to the frame configuration corresponds to the i-th modulation signal 103_i.

[0042] FIG. 3 shows an example of the configuration of the transmission panel antenna i of 106_i in FIGS. 1A, 1B, and 1C. Here, i is an integer of "1 or more and M or less". The distribution unit 302 takes the transmission signal 301 as an input, performs distribution, and outputs the first transmission signal 303_1, the second transmission signal 303_2, the third transmission signal 303_3, and the fourth transmission signal 303_4. Note that the transmission signal 301 corresponds to "the i-th transmission signal 105_i in FIGS. 1A and 1B" or "the i-th modulation signal 103_i in FIG. 1C".

[0043] The multiplication unit 304_1 takes the first transmission signal 303_1 and the control signal 300 as inputs, multiplies the first transmission signal 303_1 by a multiplication coefficient based on the control signal 300, generates the first transmission signal 305_1 after coefficient multiplication, and outputs it. Then, the first transmission signal 305_1 after coefficient multiplication is output as a radio wave from the antenna 306_1. Note that the control signal 300 corresponds to the control signal 100.

[0044] Specifically, it will be described. Let the first transmission signal 303_1 be represented as tx1(t). Here, t is time. And if the multiplication coefficient is w1, the first transmission signal 305_1 after coefficient multiplication can be represented as tx1(t) × w1. Note that tx1(t) can be represented as a complex number, and thus it may also be a real number. Also, w1 can be represented as a complex number, and thus it may also be a real number.

[0045] The multiplication unit 304_2 takes the second transmission signal 303_2 and the control signal 300 as inputs, multiplies the second transmission signal 303_2 by a multiplication coefficient based on the control signal 300, generates the second transmission signal 305_2 after coefficient multiplication, and outputs it. Then, the second transmission signal 305_2 after coefficient multiplication is output as a radio wave from the antenna 306_2.

[0046] Specifically, it will be described. Assume that the second transmission signal 303_2 is represented as tx2(t). Note that t represents time. And if the multiplication coefficient is w2, the second transmission signal 305_2 after coefficient multiplication can be represented as tx2(t)×w2. Note that tx2(t) can be represented as a complex number, and thus it may also be a real number. Also, w2 can be represented as a complex number, and thus it may also be a real number.

[0047] The multiplication unit 304_3 takes the third transmission signal 303_3 and the control signal 300 as inputs, multiplies the third transmission signal 303_3 by a multiplication coefficient based on the control signal 300, generates the third transmission signal 305_3 after coefficient multiplication, and outputs it. Then, the third transmission signal 305_3 after coefficient multiplication is output as radio waves from the antenna 306_3.

[0048] Specifically, it will be described. Assume that the third transmission signal 303_3 is represented as tx3(t). Note that t represents time. And if the multiplication coefficient is w3, the third transmission signal 305_3 after coefficient multiplication can be represented as tx3(t)×w3. Note that tx3(t) can be represented as a complex number, and thus it may also be a real number. Also, w3 can be represented as a complex number, and thus it may also be a real number.

[0049] The multiplication unit 304_4 takes the fourth transmission signal 303_4 and the control signal 300 as inputs, multiplies the fourth transmission signal 303_4 by a multiplication coefficient based on the control signal 300, generates the fourth transmission signal 305_4 after coefficient multiplication, and outputs it. Then, the fourth transmission signal 305_4 after coefficient multiplication is output as radio waves from the antenna 306_4.

[0050] Specifically, it will be described. Assume that the fourth transmission signal 303_4 is represented as tx4(t). Note that t represents time. And if the multiplication coefficient is w4, the fourth transmission signal 305_4 after coefficient multiplication can be represented as tx4(t)×w4. Note that tx4(t) can be represented as a complex number, and thus it may also be a real number. Also, w4 can be represented as a complex number, and thus it may also be a real number.

[0051] Note that "the absolute value of w1, the absolute value of w2, the absolute value of w3, and the absolute value of w4 may be equal". At this time, it corresponds to the phase change being performed. Naturally, the absolute value of w1, the absolute value of w2, the absolute value of w3, and the absolute value of w4 do not have to be equal.

[0052] The values of w1, w2, w3, and w4 may be switched for each frame, for each slot, for each mini-slot, for each plurality of symbols, or for each symbol. The switching timing of the values of w1, w2, w3, and w4 is not limited to the above example.

[0053] Also, although the transmission panel antenna in FIG. 3 is described by an example in which it is composed of four antennas (and four multiplication units), the number of antennas is not limited to four, and it may be composed of two or more antennas.

[0054] Note that the transmission panel antenna i of 106_i in FIGS. 1A, 1B, and 1C may perform directivity control by changing the characteristics of the antenna itself. At this time, the transmission panel antenna i of 106_i only needs to be composed of one or more antennas.

[0055] FIG. 4 shows the configuration of the reception panel antenna i of 151_i in FIGS. 1A, 1B, and 1C. Note that i is an integer "equal to or greater than 1 and equal to or less than m".

[0056] The multiplication unit 403_1 takes the first received signal 402_1 received by the antenna 401_1 and the control signal 400 as inputs, multiplies the first received signal 402_1 by a multiplication coefficient based on the control signal 400, and outputs the first received signal 404_1 after coefficient multiplication.

[0057] Specifically describe. Assume that the first received signal 402_1 is represented as rx1(t). Note that t is time. And if the multiplication coefficient is d1, the first received signal 404_1 after coefficient multiplication can be represented as rx1(t)×d1. Note that rx1(t) can be represented as a complex number, and thus, it may also be a real number. Also, d1 can be represented as a complex number, and thus, it may also be a real number.

[0058] The multiplication unit 403_2 takes the second received signal 402_2 received by the antenna 401_2 and the control signal 400 as inputs, and multiplies the second received signal 402_2 by a multiplication coefficient based on the control signal 400, and outputs the second received signal 404_2 after coefficient multiplication.

[0059] Specifically describe. Assume that the second received signal 402_2 is represented as rx2(t). Note that t is time. And if the multiplication coefficient is d2, the second received signal 404_2 after coefficient multiplication can be represented as rx2(t)×d2. Note that rx2(t) can be represented as a complex number, and thus, it may also be a real number. Also, d2 can be represented as a complex number, and thus, it may also be a real number.

[0060] The multiplication unit 403_3 takes the third received signal 402_3 received by the antenna 401_3 and the control signal 400 as inputs, and multiplies the third received signal 402_3 by a multiplication coefficient based on the control signal 400, and outputs the third received signal 404_3 after coefficient multiplication.

[0061] Specifically describe. Assume that the third received signal 402_3 is represented as rx3(t). Note that t is time. And if the multiplication coefficient is d3, the third received signal 404_3 after coefficient multiplication can be represented as rx3(t)×d3. Note that rx3(t) can be represented as a complex number, and thus, it may also be a real number. Also, d3 can be represented as a complex number, and thus, it may also be a real number.

[0062] The multiplication unit 403_4 takes the fourth received signal 402_4 received by the antenna 401_4 and the control signal 400 as inputs, and multiplies the fourth received signal 402_4 by a multiplication coefficient based on the control signal 400, and outputs the fourth received signal 404_4 after coefficient multiplication.

[0063] Specifically, it will be described. Let the fourth received signal 402_4 be represented as rx4(t). Here, t is assumed to be time. And if the multiplication coefficient is d4, the fourth received signal 404_4 after coefficient multiplication can be represented as rx4(t)×d4. Note that rx4(t) can be represented as a complex number, and thus it may also be a real number. Also, d4 can be represented as a complex number, and thus it may also be a real number.

[0064] The combining / composite unit 405 takes the first received signal 404_1 after coefficient multiplication, the second received signal 404_2 after coefficient multiplication, the third received signal 404_3 after coefficient multiplication, and the fourth received signal 404_4 after coefficient multiplication as inputs, combines the first received signal 404_1 after coefficient multiplication, the second received signal 404_2 after coefficient multiplication, the third received signal 404_3 after coefficient multiplication, and the fourth received signal 404_4 after coefficient multiplication, and outputs a modulation signal 406. Note that the modulation signal 406 is represented as rx1(t)×d1 + rx2(t)×d2 + rx3(t)×d3 + rx4(t)×d4.

[0065] Note that the control signal 400 corresponds to the control signal 100. And the modulation signal 406 corresponds to the i-th received signal of 152_i.

[0066] And it is also possible that "the absolute value of d1, the absolute value of d2, the absolute value of d3, and the absolute value of d4 are equal". At this time, it corresponds to the fact that a phase change has occurred. Naturally, the absolute value of d1, the absolute value of d2, the absolute value of d3, and the absolute value of d4 do not have to be equal.

[0067] The values of d1, d2, d3, and d4 may be switched for each frame, for each slot, for each mini-slot, for each plurality of symbols, or for each symbol. The switching timing of the values of d1, d2, d3, and d4 is not limited to the above example.

[0068] In addition, although the reception panel antenna in FIG. 4 is described by way of example as being composed of four antennas (and four multiplication units), the number of antennas is not limited to four, and it may be composed of two or more antennas.

[0069] Note that the reception panel antenna i of 151_i in FIGS. 1A, 1B, and 1C may perform directivity control by changing the characteristics of the antenna itself. At this time, the reception panel antenna i of 151_i may be composed of one or more antennas.

[0070] In this embodiment, it is assumed that the communication devices in FIGS. 1A, 1B, and 1C support transmission and reception in a single carrier transmission scheme.

[0071] FIG. 5 shows a configuration example of a transmission device when using a single carrier scheme based on DFT (Discrete Fourier Transform). As shown in FIG. 5, the transmission device is composed of a constellation mapper 501, tone mapping 502, IFFT (Inverse Fast Fourier Transform) 503, CP (Cyclic Prefix) insertion unit (CP insertion) 504, and transmission FE processing unit (Tx (Transmitter) FE (Front End) processing) 505. Note that other processing units may be present in the transmission device.

[0072] FIG. 6 shows a configuration example of a receiving apparatus when using a single carrier system based on DFT. As shown in FIG. 6, the receiving apparatus is configured by a receiving FE processing unit (Rx (Receiver) FE processing) 601, a CP removal unit (CP Removal) 602, an FFT (Fast Fourier Transform) 603, a tone demapping unit (Tone demapping) 604, an FDE (Frequency Domain Equalization) 605, a DFT 606, and a demapper 607. Note that other processing units may be present in the receiving apparatus.

[0073] FIG. 7 shows a configuration example of a transmitting apparatus when using a single carrier system based on the time domain. As shown in FIG. 7, the transmitting apparatus is configured by a constellation mapper 701, a CP insertion unit (CP insertion) 702, an up-sampling and pulse shaping unit (Up-sampling and pulse shaping) 703, and a transmitting FE processing unit (Tx (Transmitter) FE (Front End) processing) 704. Note that other processing units may be present in the transmitting apparatus.

[0074] FIG. 8 shows a configuration example of a receiving apparatus when using a single carrier system based on the time domain. As shown in FIG. 8, the receiving apparatus is configured by a receiving FE processing unit (Rx (Receiver) FE processing) 801, a down-sampling and match filtering unit (Down-sampling and match filtering) 802, a TDE (Time Domain Equalization) 803, a CP removal unit (CP Removal) 804, and a demapper 805. Note that other processing units may be present in the receiving apparatus.

[0075] In the above, examples of the configurations of the single-carrier transmission method, reception method, transmission device, and reception device have been described. However, the examples of the single-carrier transmission method, reception method, transmission device, and reception device are not limited to these. For example, as examples of the single-carrier method, there are "DFT (Discrete Fourier Transform)-Spread OFDM (Orthogonal Frequency Division Multiplexing)" (DFT-S OFDM), "Trajectory Constrained DFT-Spread OFDM", "Constrained DFT-Spread OFDM" (Constrained DFT-S OFDM), "OFDM based SC (Single Carrier)", "SC (Single Carrier)-FDMA (Frequency Division Multiple Access)", "Gurd interval DFT-Spread OFDM", time-domain implementation single-carrier methods (e.g., SC (Single Carrier)-QAM), and so on.

[0076] FIG. 9 shows an example of the communication state in this embodiment. As shown in FIG. 9, consider the case where the base station #1 of 901_1 communicates with the terminal #1 of 902_1, the terminal #2 of 902_2, and the terminal #3 of 902_3. However, the relationship between the base station and the terminal is not limited to this example. For example, the base station may communicate with one or more terminals.

[0077] Note that hereinafter, the case where the base station and the terminal perform TDD (Time Division Duplex), TDMA (Time Division Multiple Access), and TDM (Time Division Multiplexing) will be described as an example.

[0078] Figure 10 shows an example of the modulation signal 1000 transmitted by base station #1 of 901_1 in Figure 9. In Figure 10, the horizontal axis represents time. In the time interval from time t0 to t1, there is a sector sweep reference signal 1001. Note that the sector sweep reference signal 1001 will be described later.

[0079] The time interval from time t1 to t2 is the terminal response interval. Note that the response of the terminal will be described later.

[0080] In the time interval from time t2 to t3, there is a feedback signal 1002. Note that the feedback signal 1002 will be described later.

[0081] In the time interval from time t4 to t5, there is a frame 1003 including data symbols. Note that the frame 1003 including data symbols will be described later.

[0082] In Figure 10, it is named as the sector sweep reference signal 1001, but the name is not limited to this. It may also be called a reference signal, reference symbol, training signal, training symbol, reference signal, reference symbol, etc. Also, although it is named as the feedback signal 1002, the name is not limited to this. It may also be called a feedback symbol, a signal addressed to the terminal, a symbol addressed to the terminal, a control signal, a control symbol, etc. And although it is named as the frame 1003 including data symbols, the name is not limited to this. It may also be called a frame, slot, mini-slot, unit, etc.

[0083] Figure 11 shows an example of the sector sweep reference signal 1001 in Figure 10 transmitted by base station #1 of 901_1 in Figure 9. Assume that in Figure 11, the horizontal axis represents time.

[0084] For example, base station #1 of 901_1 having the configurations of FIGS. 1A, 1B, and 1C transmits a sector sweep reference signal 1101_1 in transmission panel antenna 1 from transmission panel antenna 1 of 106_1.

[0085] Therefore, as shown in FIG. 11, base station #1 of 901_1 having the configurations of FIGS. 1A, 1B, and 1C transmits a sector sweep reference signal 1101_i in transmission panel antenna i from transmission panel antenna i of 106_i. Note that i is an integer greater than or equal to 1 and less than or equal to M.

[0086] FIG. 12 shows a configuration example of the "sector sweep reference signal 1101_i in transmission panel antenna i" in FIG. 11. In FIG. 12, it is assumed that the horizontal axis represents time.

[0087] For example, assume that base station #1 of 901_1 having the configurations of FIGS. 1A, 1B, and 1C includes the configuration of FIG. 3 as transmission panel antenna i of 106_i.

[0088] An explanation will be given of the "reference signal 1201_1 based on the first parameter in transmission panel antenna i".

[0089] When base station #1 of 901_1 transmits the "reference signal 1201_1 based on the first parameter in transmission panel antenna i" shown in FIG. 12, base station #1 of 901_1 sets the multiplication coefficient in multiplier 304_1 in transmission panel antenna i of 106_i to w1(i,1). Assuming that the first transmission signal 303_1 in the "reference signal 1201_1 based on the first parameter in transmission panel antenna i" is tx1ref1(t), multiplier 304_1 obtains tx1ref1(t) × w1(i,1). Then, base station #1 of 901_1 transmits tx1ref1(t) × w1(i,1) from antenna 306_1 in FIG. 3. Note that t represents time.

[0090] When the base station #1 of 901_1 transmits the "Reference Signal 1201_1 Based on the First Parameter in Transmission Panel Antenna i" shown in FIG. 12, the base station #1 of 901_1 sets the multiplication coefficient in the multiplier 304_2 in the transmission panel antenna i of 106_i as w2(i,1). If the second transmission signal 303_2 in the "Reference Signal 1201_1 Based on the First Parameter in Transmission Panel Antenna i" is tx2ref1(t), the multiplier 304_2 obtains tx2ref1(t)×w2(i,1). Then, the base station #1 of 901_1 transmits tx2ref1(t)×w2(i,1) from the antenna 306_2 in FIG. 3.

[0091] When the base station #1 of 901_1 transmits the "Reference Signal 1201_1 Based on the First Parameter in Transmission Panel Antenna i" shown in FIG. 12, the base station #1 of 901_1 sets the multiplication coefficient in the multiplier 304_3 in the transmission panel antenna i of 106_i as w3(i,1). If the third transmission signal 303_3 in the "Reference Signal 1201_1 Based on the First Parameter in Transmission Panel Antenna i" is tx3ref1(t), the multiplier 304_3 obtains tx3ref1(t)×w3(i,1). Then, the base station #1 of 901_1 transmits tx3ref1(t)×w3(i,1) from the antenna 306_3 in FIG. 3.

[0092] When the base station #1 of 901_1 transmits the "Reference Signal 1201_1 Based on the First Parameter in Transmission Panel Antenna i" shown in FIG. 12, the base station #1 of 901_1 sets the multiplication coefficient in the multiplier 304_4 in the transmission panel antenna i of 106_i as w4(i,1). If the fourth transmission signal 303_4 in the "Reference Signal 1201_1 Based on the First Parameter in Transmission Panel Antenna i" is tx4ref1(t), the multiplier 304_4 obtains tx4ref1(t)×w4(i,1). Then, the base station #1 of 901_1 transmits tx4ref1(t)×w4(i,1) from the antenna 306_4 in FIG. 3.

[0093] Describe the "Reference Signal 1201_j by the j-th Parameter in the Transmission Panel Antenna i".

[0094] When the base station #1 of 901_1 transmits the "Reference Signal 1201_j by the j-th Parameter in the Transmission Panel Antenna i" shown in FIG. 12, the base station #1 of 901_1 sets the multiplication coefficient in the multiplication unit 304_1 in the transmission panel antenna i of 106_i as w1(i,j). If the first transmission signal 303_1 in the "Reference Signal 1201_j by the j-th Parameter in the Transmission Panel Antenna i" is tx1refj(t), the multiplication unit 304_1 obtains tx1refj(t)×w1(i,j). Then, the base station #1 of 901_1 transmits tx1refj(t)×w1(i,j) from the antenna 306_1 in FIG. 3. Note that t is time.

[0095] When the base station #1 of 901_1 transmits the "Reference Signal 1201_j by the j-th Parameter in the Transmission Panel Antenna i" shown in FIG. 12, the base station #1 of 901_1 sets the multiplication coefficient in the multiplication unit 304_2 in the transmission panel antenna i of 106_i as w2(i,j). If the second transmission signal 303_2 in the "Reference Signal 1201_j by the j-th Parameter in the Transmission Panel Antenna i" is tx2refj(t), the multiplication unit 304_2 obtains tx2refj(t)×w2(i,j). Then, the base station #1 of 901_1 transmits tx2refj(t)×w2(i,j) from the antenna 306_2 in FIG. 3.

[0096] When the base station #1 of 901_1 transmits the "Reference Signal 1201_j according to the j-th parameter in the Transmission Panel Antenna i" shown in FIG. 12, the base station #1 of 901_1 sets the multiplication coefficient in the multiplier 304_3 in the transmission panel antenna i of 106_i to w3(i,j). Assuming that the third transmission signal 303_3 in the "Reference Signal 1201_j according to the j-th parameter in the Transmission Panel Antenna i" is tx3refj(t), the multiplier 304_3 obtains tx3refj(t)×w3(i,j). Then, the base station #1 of 901_1 transmits tx3refj(t)×w3(i,j) from the antenna 306_3 in FIG. 3.

[0097] When the base station #1 of 901_1 transmits the "Reference Signal 1201_j according to the j-th parameter in the Transmission Panel Antenna i" shown in FIG. 12, the base station #1 of 901_1 sets the multiplication coefficient in the multiplier 304_4 in the transmission panel antenna i of 106_i to w4(i,j). Assuming that the fourth transmission signal 303_4 in the "Reference Signal 1201_j according to the j-th parameter in the Transmission Panel Antenna i" is tx4refj(t), the multiplier 304_4 obtains tx4refj(t)×w4(i,j). Then, the base station #1 of 901_1 transmits tx4refj(t)×w4(i,j) from the antenna 306_4 in FIG. 3.

[0098] In the case of FIG. 12, j is an integer greater than or equal to 1 and less than or equal to 4. In FIG. 12, the number of parameter changes Z is set to Z = 4, but the number of parameter changes Z is not limited to 4. As long as Z is an integer greater than or equal to 1 or an integer greater than or equal to 2, the same implementation is possible. At this time, j is an integer greater than or equal to 1 and less than or equal to Z.

[0099] As shown in FIGS. 11 and 12, when the base station #1 of 901_1 transmits the "Sector Sweep Reference Signal 1101_i in the Transmission Panel Antenna i", the "Reference Signal 1201_j according to the j-th parameter in the Transmission Panel Antenna i" is assumed to include, for example, the following information. · ID (identification number) of the transmission panel antenna (here, for example, corresponding to i) · Identification number (ID) of the parameters used in beamforming (directivity control) (here, for example, corresponding to j) · Number of slots in which the terminal can transmit the reference signal for sector sweep when transmitting the reference signal for sector sweep (number of terminals capable of transmitting the reference signal for sector sweep) (to be described later).

[0100] By the base station #1 of 901_1 transmitting the "ID (identification number) of the transmission panel antenna" and the "identification number (ID) of the parameters used in beamforming (directivity control)", the terminal can know the "ID (identification number) of the transmission panel antenna" and the "identification number (ID) of the parameters used in beamforming (directivity control)" that it has received, and the base station #1 of 901_1 and the terminal can perform appropriate control, thereby obtaining the effect of improving the reception quality of data.

[0101] Note that the "number of slots in which the terminal can transmit the reference signal for sector sweep when transmitting the reference signal for sector sweep (number of terminals capable of transmitting the reference signal for sector sweep)" may be changed according to the frame and / or time, etc. Thereby, the effect of improving the data transmission efficiency of the communication system can be obtained.

[0102] Next, the operation in the time interval from time t1 to t2, which is the terminal response interval in FIG. 10, will be described.

[0103] FIG. 13 shows an example of the operation in the time interval from time t1 to t2, which is the terminal response interval. In FIG. 13, the horizontal axis is assumed to be time.

[0104] As shown in FIGS. 10 and 13, for example, it is assumed that the base station #1 of 901_1 transmitted a sector sweep reference signal in the time interval from time t0 to t1. Then, in the terminal response interval which is the time interval from time t1 to t2, as shown in FIG. 13, there are a "sector sweep reference signal" transmission section 1301_1 for the first terminal, a "sector sweep reference signal" transmission section 1301_2 for the second terminal, a "sector sweep reference signal" transmission section 1301_3 for the third terminal, and a "sector sweep reference signal" transmission section 1301_4 for the fourth terminal.

[0105] Therefore, in the case of FIG. 13, it is set that the number of slots in which the base station #1 of 901_1 can transmit a sector sweep reference signal (the number of terminals that can transmit a sector sweep reference signal) when a terminal transmits a sector sweep reference signal is 4.

[0106] FIG. 14 shows an example regarding the occupancy of terminals in the "sector sweep reference signal" transmission section 1301_1 for the first terminal, the "sector sweep reference signal" transmission section 1301_2 for the second terminal, the "sector sweep reference signal" transmission section 1301_3 for the third terminal, and the "sector sweep reference signal" transmission section 1301_4 shown in FIG. 13. In FIG. 14, it is assumed that the horizontal axis represents time.

[0107] The terminal #1 of 902_1 in FIG. 9 receives the sector sweep reference signal 1001 transmitted by the base station #1 of 901_1, and estimates the "transmission panel antenna and parameter number" with good reception quality among the transmission panel antennas of the base station #1 of 901_1. This estimation can be performed by obtaining the sector sweep reference signal 1001 and the "ID (identification) (identification number) of the transmission panel antenna" and the "identification number (ID) of the parameter used in beamforming (directivity control)" included therein.

[0108] The terminal #1 of 902_1 is presumed to be, for example, "transmission panel antenna a1 and parameter b1" as a "transmission panel antenna and parameter" with good reception quality.

[0109] Also, while the terminal #1 of 902_1 estimates a "transmission panel antenna and parameter" with good reception quality, it will obtain information on "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" when the terminal transmits a reference signal for sector sweep. In the case of FIG. 14, the terminal #1 of 902_1 will obtain information that "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is 4.

[0110] In this case, the terminal #1 of 902_1 uses a random number to obtain a value, for example, any of "0", "1", "2", "3". For example, assume that the terminal #1 of 902_1 obtains "0" using a random number. In this case, since "0" + 1 = 1, the terminal #1 of 902_1 uses the "transmission section 1301_1 of the reference signal for sector sweep for the first (= "0" + 1) terminal" in FIG. 14 to transmit the reference signal 1401_1 for sector sweep. Here, a transmission section of the reference signal for sector sweep is set using a random number, but instead of a random number, for example, a random number of integers or natural numbers, irregular integers or natural numbers, regular integers or natural numbers, integers or natural numbers held uniquely by the terminal, etc. can be used to set the transmission section of the reference signal for sector sweep. Therefore, the setting of the transmission section of the reference signal for sector sweep is not limited to the above example, and for example, the transmission section of the reference signal for sector sweep is set for each terminal. This point is also applicable to the following similar explanations.

[0111] Note that the sector sweep reference signal 1401_1 includes the information on the "transmission panel antenna and parameters" with good reception quality obtained by terminal #1 of 902_1, that is, the information on "transmission panel antenna a1 and parameter b1". This will be explained later.

[0112] Similarly, the terminal #2 of 902_2 in Fig. 9 receives the sector sweep reference signal 1001 transmitted by the base station #1 of 901_1, and estimates the "transmission panel antenna and parameter number" with good reception quality among the transmission panel antennas of the base station #1 of 901_1. Note that this estimation can be performed by obtaining the sector sweep reference signal 1001 and the "ID (identification number) of the transmission panel antenna" and the "identification number (ID) of the parameter used in beamforming (directivity control)" included therein.

[0113] Assume that the terminal #2 of 902_2 estimates, as the "transmission panel antenna and parameters" with good reception quality, for example, "transmission panel antenna a2 and parameter b2".

[0114] Also, while estimating the "transmission panel antenna and parameters" with good reception quality, the terminal #2 of 902_2 obtains the information on "the number of slots available for transmitting the sector sweep reference signal (the number of terminals capable of transmitting the sector sweep reference signal)" when the terminal transmits the sector sweep reference signal. In the case of Fig. 14, the terminal #2 of 902_2 obtains the information that "the number of slots available for transmitting the sector sweep reference signal (the number of terminals capable of transmitting the sector sweep reference signal)" is 4.

[0115] In this case, the terminal #2 of 902_2 obtains a value of, for example, any one of "0", "1", "2", and "3" using a random number. For example, assume that the terminal #2 of 902_2 obtains "2" using a random number. In this case, since "2" + 1 = 3, the terminal #2 of 902_2 uses the "sector sweep reference signal transmission section 1301_3 for the third (= "2" + 1) terminal" in FIG. 14 to transmit the sector sweep reference signal 1401_2.

[0116] Note that the sector sweep reference signal 1401_2 is assumed to include information on the "transmission panel antenna and parameters" with good reception quality obtained by the terminal #2 of 902_2, that is, information on the "transmission panel antenna a2 and parameter b2". This will be described later.

[0117] Therefore, the terminal #i of 902_i receives the sector sweep reference signal 1001 transmitted by the base station #1 of 901_1 and estimates the "transmission panel antenna and parameter number" with good reception quality among the transmission panel antennas of the base station #1 of 901_1. Note that this estimation can be performed by obtaining the sector sweep reference signal 1001 and the "ID (identification) of the transmission panel antenna" and the "identification number (ID) of the parameter used in beamforming (directivity control)" included therein. Note that, for example, i is an integer of 1 or more.

[0118] Assume that the terminal #i of 902_i estimates the "transmission panel antenna and parameters" with good reception quality as, for example, "transmission panel antenna ai and parameter bi".

[0119] In addition, the terminal #i of 902_i estimates "transmission panel antenna and parameters" with good reception quality, and at the same time obtains information on "the number of slots in which the reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting the reference signal for sector sweep)" when the terminal transmits the reference signal for sector sweep. In the case of FIG. 14, the terminal #i of 902_i will obtain information that the number of slots in which the reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting the reference signal for sector sweep) is 4 when the terminal transmits the reference signal for sector sweep.

[0120] In this case, the terminal #i of 902_i uses a random number to obtain a value of, for example, any one of "0", "1", "2", "3". For example, assume that the terminal #i of 902_i obtains "j" using a random number. Note that j is a value of any one of "0", "1", "2", "3". In this case, the terminal #i of 902_i transmits the reference signal 1401_i for sector sweep using the "transmission section 1301_(j + 1) of the reference signal for sector sweep for the (j + 1)-th terminal" in FIG. 14.

[0121] It is assumed that the reference signal 1401_i for sector sweep includes information on "transmission panel antenna and parameters" with good reception quality obtained by the terminal #i of 902_i, that is, information on "transmission panel antenna ai and parameters bi". This will be described later.

[0122] By doing the above, it is possible to reduce the collision of the reference signals for sector sweep transmitted by each terminal, and thereby increase the number of reference signals for sector sweep that the base station can receive, and obtain the effect of increasing the number of terminals with which the base station can communicate.

[0123] The configuration of the sector sweep reference signal 1401_i transmitted by the terminal #i of 902_i described with reference to FIG. 14 will be described. For simplicity of explanation, the terminal #i of 902_i is assumed to have the configurations shown in FIGS. 1A, 1B, and 1C. Also, it is assumed that the terminal #i of 902_i having the configurations shown in FIGS. 1A, 1B, and 1C has the configuration shown in FIG. 3 as the transmission panel antenna xi of 106_xi. However, the configuration of the terminal #i of 902_i is not limited to the configurations shown in FIGS. 1A, 1B, and 1C, and the configuration of the transmission panel antenna xi of 106_xi of the terminal #i of 902_i having the configurations shown in FIGS. 1A, 1B, and 1C is not limited to FIG. 3.

[0124] FIG. 11 shows an example of the sector sweep reference signal 1401_i transmitted by the terminal #i of 902_i. In FIG. 11, the horizontal axis is assumed to represent time.

[0125] For example, the terminal #i of 902_i having the configurations shown in FIGS. 1A, 1B, and 1C transmits the sector sweep reference signal 1101_1 in the transmission panel antenna 1 from the transmission panel antenna 1 of 106_1.

[0126] Therefore, as shown in FIG. 11, the terminal #i of 902_i having the configurations shown in FIGS. 1A, 1B, and 1C transmits the sector sweep reference signal 1101_xi in the transmission panel antenna xi from the transmission panel antenna xi of 106_xi. Here, xi is an integer greater than or equal to 1 and less than or equal to M.

[0127] FIG. 15 shows a configuration example of the "sector sweep reference signal 1101_xi in the transmission panel antenna xi" in FIG. 11. In FIG. 15, the horizontal axis is assumed to represent time.

[0128] For example, it is assumed that the terminal #i of 902_i having the configurations shown in FIGS. 1A, 1B, and 1C has the configuration shown in FIG. 3 as the transmission panel antenna xi of 106_xi.

[0129] Describe "Reference Signal 1501_1 Based on the First Parameter in Transmission Panel Antenna xi".

[0130] When the terminal #i of 902_i transmits the "Reference Signal 1501_1 Based on the First Parameter in Transmission Panel Antenna xi" shown in FIG. 15, the terminal #i of 902_i sets the multiplication coefficient of the multiplication unit 304_1 in the transmission panel antenna xi of 106_xi as w1(xi,1). If the first transmission signal 303_1 in the "Reference Signal 1501_1 Based on the First Parameter in Transmission Panel Antenna xi" is tx1ref1(t), the multiplication unit 304_1 obtains tx1ref1(t)×w1(xi,1). Then, the terminal #i of 902_i transmits tx1ref1(t)×w1(xi,1) from the antenna 306_1 in FIG. 3. Here, t is time.

[0131] When the terminal #i of 902_i transmits the "Reference Signal 1501_1 Based on the First Parameter in Transmission Panel Antenna xi" shown in FIG. 15, the terminal #i of 902_i sets the multiplication coefficient of the multiplication unit 304_2 in the transmission panel antenna xi of 106_xi as w2(xi,1). If the second transmission signal 303_2 in the "Reference Signal 1501_1 Based on the First Parameter in Transmission Panel Antenna xi" is tx2ref1(t), the multiplication unit 304_2 obtains tx2ref1(t)×w2(xi,1). Then, the terminal #i of 902_i transmits tx2ref1(t)×w2(xi,1) from the antenna 306_2 in FIG. 3.

[0132] When the terminal #i of 902_i transmits the "Reference Signal 1501_1 Based on the First Parameter in the Transmission Panel Antenna xi" shown in FIG. 15, the terminal #i of 902_i sets the multiplication coefficient of the multiplication unit 304_3 in the transmission panel antenna xi of 106_xi as w3(xi,1). If the third transmission signal 303_3 in the "Reference Signal 1501_1 Based on the First Parameter in the Transmission Panel Antenna xi" is tx3ref1(t), the multiplication unit 304_3 obtains tx3ref1(t)×w3(xi,1). Then, the terminal #i of 902_i transmits tx3ref1(t)×w3(xi,1) from the antenna 306_3 in FIG. 3.

[0133] When the terminal #i of 902_i transmits the "Reference Signal 1501_1 Based on the First Parameter in the Transmission Panel Antenna xi" shown in FIG. 15, the terminal #i of 902_i sets the multiplication coefficient of the multiplication unit 304_4 in the transmission panel antenna xi of 106_xi as w4(xi,1). If the fourth transmission signal 303_4 in the "Reference Signal 1501_1 Based on the First Parameter in the Transmission Panel Antenna xi" is tx4ref1(t), the multiplication unit 304_4 obtains tx4ref1(t)×w4(xi,1). Then, the terminal #i of 902_i transmits tx4ref1(t)×w4(xi,1) from the antenna 306_4 in FIG. 3.

[0134] The "Reference Signal 1501_j Based on the j-th Parameter in the Transmission Panel Antenna xi" will be described.

[0135] When the terminal #i of 902_i transmits the "Reference Signal 1501_j according to the j-th parameter in the Transmission Panel Antenna xi" shown in FIG. 15, the terminal #i of 902_i sets the multiplication coefficient of the multiplication unit 304_1 in the transmission panel antenna xi of 106_xi as w1(xi,j). If the first transmission signal 303_1 in the "Reference Signal 1501_j according to the j-th parameter in the Transmission Panel Antenna xi" is tx1refj(t), the multiplication unit 304_1 obtains tx1refj(t)×w1(xi,j). Then, the terminal #i of 902_i transmits tx1refj(t)×w1(xi,j) from the antenna 306_1 in FIG. 3. Note that t is time.

[0136] When the terminal #i of 902_i transmits the "Reference Signal 1501_j according to the j-th parameter in the Transmission Panel Antenna xi" shown in FIG. 15, the terminal #i of 902_i sets the multiplication coefficient of the multiplication unit 304_2 in the transmission panel antenna xi of 106_xi as w2(xi,j). If the second transmission signal 303_2 in the "Reference Signal 1501_j according to the j-th parameter in the Transmission Panel Antenna xi" is tx2refj(t), the multiplication unit 304_2 obtains tx2refj(t)×w2(xi,j). Then, the terminal #i of 902_i transmits tx2refj(t)×w2(xi,j) from the antenna 306_2 in FIG. 3.

[0137] When the terminal #i of 902_i transmits the "Reference Signal 1501_j according to the j-th parameter in the Transmission Panel Antenna xi" shown in FIG. 15, the terminal #i of 902_i sets the multiplication coefficient of the multiplication unit 304_3 in the transmission panel antenna xi of 106_xi as w3(xi,j). If the third transmission signal 303_3 in the "Reference Signal 1501_j according to the j-th parameter in the Transmission Panel Antenna xi" is tx3refj(t), the multiplication unit 304_3 obtains tx3refj(t)×w3(xi,j). Then, the terminal #i of 902_i transmits tx3refj(t)×w3(xi,j) from the antenna 306_3 in FIG. 3.

[0138] When the terminal #i of 902_i transmits the "reference signal 1501_j according to the j-th parameter in the transmission panel antenna xi" shown in FIG. 15, the terminal #i of 902_i sets the multiplication coefficient of the multiplication unit 304_4 in the transmission panel antenna xi of 106_xi to w4(xi,j). Assuming that the fourth transmission signal 303_4 in the "reference signal 1501_j according to the j-th parameter in the transmission panel antenna xi" is tx4refj(t), the multiplication unit 304_4 obtains tx4refj(t)×w4(xi,j). Then, the terminal #i of 902_i transmits tx4refj(t)×w4(xi,j) from the antenna 306_4 in FIG. 3.

[0139] In the case of FIG. 15, j is an integer greater than or equal to 1 and less than or equal to 4. In FIG. 15, the number of parameter changes Z is set to Z = 4, but the number of parameter changes Z is not limited to 4. As long as Z is an integer greater than or equal to 1 or an integer greater than or equal to 2, it can be implemented in the same way. At this time, j is an integer greater than or equal to 1 and less than or equal to Z.

[0140] As shown in FIGS. 11 and 15, when the terminal #i of 902_i transmits the "sector sweep reference signal 1101_xi in the transmission panel antenna xi", the "reference signal 1501_j according to the j-th parameter in the transmission panel antenna xi" is assumed to include, for example, the following information.

[0141] · Information on the "transmission panel antenna and parameters" of the base station #1 of 901_1 with good reception quality as described above.

[0142] Therefore, the terminal #i of 902_i will transmit the information on the "transmission panel antenna and parameters" of the base station #1 of 901_1 with good reception quality in the "sector sweep reference signal 1101_1 in the transmission panel antenna 1", "sector sweep reference signal 1101_2 in the transmission panel antenna 2", ···, "sector sweep reference signal 1101_M in the transmission panel antenna M" in FIG. 11.

[0143] Also, in the case of the "reference signal 1501_1 according to the first parameter in the transmission panel antenna xi", "reference signal 1501_2 according to the second parameter in the transmission panel antenna xi", "reference signal 1501_3 according to the third parameter in the transmission panel antenna xi", and "reference signal 1501_4 according to the fourth parameter in the transmission panel antenna xi" in FIG. 15 of "reference signal 1101_1 for sector sweep in transmission panel antenna 1", "reference signal 1101_2 for sector sweep in transmission panel antenna 2",..., "reference signal 1101_M for sector sweep in transmission panel antenna M" in FIG. 11, the terminal #i of 902_i will transmit the information of "transmission panel antenna and parameters" of base station #1 of 901_1 with good reception quality.

[0144] In this case, for base station #1 of 901_1, for example, even if an omnidirectional antenna is used, it is highly likely to receive any one of "reference signal 1101_1 for sector sweep in transmission panel antenna 1", "reference signal 1101_2 for sector sweep in transmission panel antenna 2",..., "reference signal 1101_M for sector sweep in transmission panel antenna M" transmitted by terminal #i of 902_i. This is because terminal #i of 902_i is performing transmission beamforming (directivity control). As a result, there is a high possibility that base station #1 of 901_1 can obtain the information of "transmission panel antenna and parameters" of base station #1 of 901_1 with good reception quality transmitted by terminal #i of 902_i. Therefore, base station #1 of 901_1 can transmit a modulation signal to terminal #i of 902_i based on the information of "transmission panel antenna and parameters" of base station #1 of 901_1 with good reception quality, and terminal #i of 902_i can receive the modulation signal with high reception quality.

[0145] Note that, as shown in FIG. 14, when multiple terminals are transmitting a sector sweep reference signal, the base station #1 of 901_1 can obtain the information of the "transmission panel antenna and parameters" of the base station #1 of 901_1 with good reception quality from multiple terminals. Thus, based on the information of the "transmission panel antenna and parameters" of the base station #1 of 901_1 with good reception quality from multiple terminals, the base station #1 of 901_1 can transmit a modulation signal to multiple terminals, and the effect that multiple terminals can receive the modulation signal with high reception quality can be obtained.

[0146] Also, as shown in FIGS. 11 and 15, when the terminal #i of 902_i transmits the "sector sweep reference signal 1101_xi in the transmission panel antenna xi", the "reference signal 1501_j according to the j-th parameter in the transmission panel antenna xi" may include, for example, the following information. · ID (identification number) of the transmission panel antenna (here, for example, corresponding to i) · Identification number (ID) of the parameter used in beamforming (directivity control) (here, for example, corresponding to j)

[0147] By the terminal #i of 902_i transmitting the "ID (identification number) of the transmission panel antenna" and the "identification number (ID) of the parameter used in beamforming (directivity control)", the base station #1 of 901_1 can know the "ID (identification number) of the transmission panel antenna" and the "identification number (ID) of the parameter used in beamforming (directivity control)" that it has received, and the terminal #i of 902_i and the base station #1 of 901_1 can perform appropriate control, thereby obtaining the effect of improving the reception quality of data.

[0148] FIG. 16 shows an example of the configuration of the feedback signal 1002 transmitted by the base station #1 of 901_1 existing in the time interval from t2 to t3 in FIG. 10. In FIG. 16, it is assumed that the horizontal axis represents time. In this example, since the number of slots in which the terminal can transmit the reference signal for sector sweep (the number of terminals that can transmit the reference signal for sector sweep) is 4 when the terminal transmits the reference signal for sector sweep, as shown in FIG. 16, the feedback signal 1002 includes four feedback signals for terminals, namely, the feedback signal 1601_1 for the first terminal, the feedback signal 1601_2 for the second terminal, the feedback signal 1601_3 for the third terminal, and the feedback signal 1601_4 for the fourth terminal. For example, when the number of slots in which the terminal can transmit the reference signal for sector sweep (the number of terminals that can transmit the reference signal for sector sweep) is Ω when the terminal transmits the reference signal for sector sweep, the feedback signal 1002 may be configured such that there are feedback signals for Ω terminals. However, Ω is an integer of 1 or more or an integer of 2 or more.

[0149] For example, as shown in FIG. 14, when the terminal #1 of 902_1 transmits the reference signal 1401_1 for sector sweep and the terminal #2 of 902_2 transmits the reference signal 1401_2 for sector sweep, the base station #1 of 901_1 transmits a feedback signal to the terminal #1 of 902_1 using the feedback signal 1601_1 for the first terminal and transmits a feedback signal to the terminal #2 of 902_2 using the feedback signal 1601_3 for the third terminal.

[0150] At this time, it is assumed that the feedback signal 1601_1 for the first terminal includes information such as being able to communicate with the terminal #1 of 902_1 (or including a symbol for the terminal #1 of 902_1 in the frame 1003 including the data symbol in FIG. 10).

[0151] And assume that the feedback signal 1601_3 for the third terminal includes information such as being able to communicate with the terminal #2 of 902_2 (or including the symbol for the terminal #2 of 902_2 in the frame 1003 including the data symbol in FIG. 10).

[0152] Based on the information of "the transmission panel antenna and parameters of the base station #1 of 901_1 with good reception quality" transmitted by the terminal #1 of 902_1, the base station #1 of 901_1 will select the transmission panel antenna, set the parameters of beamforming, and transmit the feedback signal 1601_1 for the first terminal.

[0153] Similarly, based on the information of "the transmission panel antenna and parameters of the base station #1 of 901_1 with good reception quality" transmitted by the terminal #2 of 902_2, the base station #1 of 901_1 will select the transmission panel antenna, set the parameters of beamforming, and transmit the feedback signal 1601_3 for the third terminal.

[0154] FIG. 17 shows an example of the configuration of frame 1003 including data symbols transmitted by base station #1 of 901_1, which exists in the time interval from t4 to t5 in FIG. 10. In FIG. 17, it is assumed that the horizontal axis represents time. In this example, since the number of slots in which the terminal can transmit the sector sweep reference signal (the number of terminals capable of transmitting the sector sweep reference signal) is 4 when the terminal transmits the sector sweep reference signal, as shown in FIG. 17, in frame 1003 including data symbols, there are modulation signals (slots) addressed to four terminals, such as modulation signal (slot for the first terminal) 1701_1 addressed to the first terminal, modulation signal (slot for the second terminal) 1701_2 addressed to the second terminal, modulation signal (slot for the third terminal) 1701_3 addressed to the third terminal, and modulation signal (slot for the fourth terminal) 1701_4 addressed to the fourth terminal. For example, when the number of slots in which the terminal can transmit the sector sweep reference signal (the number of terminals capable of transmitting the sector sweep reference signal) is Ω when the terminal transmits the sector sweep reference signal, frame 1003 including data symbols may be configured such that there are Ω modulation signals (slots) addressed to terminals. However, Ω is an integer of 1 or more or an integer of 2 or more.

[0155] For example, as shown in FIG. 14, when terminal #1 of 902_1 transmits sector sweep reference signal 1401_1 and terminal #2 of 902_2 transmits sector sweep reference signal 1401_2, base station #1 of 901_1 transmits a modulation signal (slot) to terminal #1 of 902_1 using modulation signal (slot for the first terminal) 1701_1 and transmits a modulation signal (slot) to terminal #2 of 902_2 using modulation signal (slot for the third terminal) 1701_3.

[0156] At this time, it is assumed that modulation signal (slot for the first terminal) 1701_1 includes, for example, data symbols (data, information) addressed to terminal #1 of 902_1.

[0157] And assume that the modulation signal (slot for the third terminal) 1701_3 addressed to the third terminal contains, for example, data symbols (data, information) addressed to terminal #2 of 902_2.

[0158] Based on the information of "transmission panel antenna and parameters" of base station #1 of 901_1 with good reception quality sent by terminal #1 of 902_1, base station #1 of 901_1 will select a transmission panel antenna, set beamforming parameters, and transmit the modulation signal (slot for the first terminal) 1701_1 addressed to the first terminal.

[0159] Similarly, based on the information of "transmission panel antenna and parameters" of base station #1 of 901_1 with good reception quality sent by terminal #2 of 902_2, base station #1 of 901_1 will select a transmission panel antenna, set beamforming parameters, and transmit the modulation signal (slot for the third terminal) 1701_3 addressed to the third terminal.

[0160] Note that in FIG. 16, the first-terminal feedback signal 1601_1 may contain the information that "base station #1 of 901_1 receives the sector sweep reference signal 1401_1 sent by terminal #1 of 902_1, estimates the 'transmission panel antenna and parameters' of terminal #1 of 902_1 with good reception quality, and this information".

[0161] Thereby, based on the information of the "transmission panel antenna and parameters" of terminal #1 of 902_1 with good reception quality obtained by terminal #1 of 902_1 from base station #1 of 901_1, terminal #1 of 902_1 selects a transmission panel antenna, determines a beamforming method, and transmits symbols, frames, and / or modulation signals to base station #1 of 901_1, so that the reception quality of data can be improved at base station #1 of 901_1.

[0162] In FIG. 16, the base station #1 of 901_1 may receive the sector sweep reference signal 1401_2 transmitted by the terminal #2 of 902_2, estimate the "transmission panel antenna and parameters" of the terminal #2 of 902_2 with good reception quality, and the feedback signal 1601_3 for the third terminal may include this information.

[0163] As a result, based on the information of the "transmission panel antenna and parameters" of the terminal #2 of 902_2 with good reception quality obtained by the terminal #2 of 902_2 from the base station #2 of 901_1, the terminal #2 of 902_2 selects a transmission panel antenna, determines a beamforming method, and transmits a symbol, frame, and / or modulation signal to the base station #1 of 901_1, so that the reception quality of data can be improved at the base station #1 of 901_1.

[0164] Also, in the time interval from t3 to t4, the terminal, that is, in the above description, the terminal #1 of 902_1 and the terminal #2 of 902_2 may transmit a modulation signal including information such as ACK (acknowledgement) indicating that the signal of the base station #1 of 901_1 can be received to the base station #1 of 901_1.

[0165] In the modulation signal (slot for the first terminal) 1701_1 for the first terminal in FIG. 17, in addition to data symbols, for example, "reference signals such as DMRS (demodulation reference signal), PTRS (phase tracking reference signal), SRS (sounding reference signal)", pilot symbols, pilot signals, preambles, symbols including control information, etc. may be included. The symbols including control information may include information of the destination terminal (ID capable of identifying the terminal), transmission method of the modulation signal, information of the modulation method, information of the error correction coding method (code length, coding rate, etc.), information of MCS (Modulation and Coding Scheme), etc.

[0166] Similarly, in the modulation signal (slot for the second terminal) 1701_2 for the second terminal, the modulation signal (slot for the third terminal) 1701_3 for the third terminal, and the modulation signal (slot for the fourth terminal) 1701_4 for the fourth terminal, in addition to data symbols, for example, "reference signals such as DMRS, PTRS, and SRS", pilot symbols, pilot signals, preambles, symbols including control information, etc. may be included. Note that the symbols including control information may include information on the destination terminal (ID capable of identifying the terminal), the transmission method of the modulation signal, information on the modulation method, information on the error correction coding method (code length, coding rate, etc.), information on MCS, etc.

[0167] FIG. 18 shows an example of a situation when the base station #1 of 901_1 communicates with "the terminal #1 of 902_1, the terminal #2 of 902_2, and the terminal #3 of 902_3" as shown in FIG. 9. FIG. 18(A) shows an example of the transmission status of the modulation signal of the base station #1 of 901_1, and FIG. 18(B) shows an example of the transmission status of the modulation signals of "the terminal #1 of 902_1, the terminal #2 of 902_2, and the terminal #3 of 902_3". In FIGS. 18(A) and 18(B), it is assumed that the horizontal axis represents time.

[0168] First, the base station #1 of 901_1 transmits the sector sweep reference signal 1801_1. Since this has already been described with reference to FIG. 10, the description is omitted.

[0169] Then, terminals such as "the terminal #1 of 902_1, the terminal #2 of 902_2, and the terminal #3 of 902_3" transmit the sector sweep reference signal 1851_1. Since this has already been described with reference to FIGS. 13, 14, etc., the description is omitted.

[0170] The base station #1 of 901_1 transmits the feedback signal 1802_1. Since this has already been described with reference to FIG. 16, the description is omitted.

[0171] After that, base station #1 of 901_1 transmits "Frame 1803_1 containing data symbols". Regarding this point, since it has already been explained with reference to FIG. 17, the explanation is omitted. (Therefore, "Frame 1803_1 containing data symbols" is considered, for example, as a downlink frame.)

[0172] Then, terminals such as "Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3" transmit "Frame 1852_1 containing data symbols". Regarding the configuration of this frame, it will be described later with reference to FIG. 20. (Therefore, "Frame 1852_1 containing data symbols" is considered, for example, as an uplink frame.)

[0173] Next, base station #1 of 901_1 transmits "Frame 1803_2 containing data symbols". The method of configuring "Frame 1803_2 containing data symbols" is as described with reference to FIG. 17.

[0174] Then, terminals such as "Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3" transmit "Frame 1852_2 containing data symbols". Regarding the configuration of this frame, it will be described later with reference to FIG. 20.

[0175] FIG. 19 shows an example of the transmission status of the modulation signals of base station #1 of 901_1 after FIG. 18 and the transmission status of the modulation signals of terminals such as "Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3".

[0176] FIG. 19(A) shows an example of the transmission status of the modulation signal of base station #1 of 901_1 and is a time continuation of the transmission status of the modulation signal of base station #1 of 901_1 in FIG. 18(A).

[0177] FIG. 19(B) shows an example of the transmission status of the modulation signals of "Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3", and is a time continuation of the transmission status of the modulation signals of "Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3" in FIG. 18(B).

[0178] Note that in FIGS. 19(A) and 19(B), the horizontal axis is assumed to be time.

[0179] After FIGS. 18(A) and (B), base station #1 of 901_1 transmits "Frame 1803_3 including data symbols". Note that the method of configuring "Frame 1803_2 including data symbols" is as described with reference to FIG. 17.

[0180] Then, terminals such as "Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3" transmit "Frame 1852_3 including data symbols". Note that the configuration of this frame will be described later with reference to FIG. 20.

[0181] Next, base station #1 of 901_1 transmits the sector sweep reference signal 1801_2. Note that this has already been described with reference to FIG. 10, so the description is omitted.

[0182] Then, terminals such as "Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3" transmit the sector sweep reference signal 1851_2. Note that this has already been described with reference to FIGS. 13, 14, etc., so the description is omitted.

[0183] Base station #1 of 901_1 transmits the feedback signal 1802_2. Note that this has already been described with reference to FIG. 16, so the description is omitted.

[0184] After that, base station #1 of 901_1 transmits "Frame 1803_4 containing data symbols". Note that the explanation for this point has already been given with reference to FIG. 17, so the explanation is omitted.

[0185] Then, terminals such as "Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3" transmit "Frame 1852_4 containing data symbols". Note that the configuration of this frame will be described later with reference to FIG. 20.

[0186] In this way, before "the transmission of the 'frame containing data symbols' by base station #1 of 901_1 and / or the transmission of the 'frame containing data symbols' by terminals such as 'Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3'", base station #1 of 901_1 and the terminals transmit a sector sweep reference signal, and after "the transmission of the 'frame containing data symbols' by base station #1 of 901_1 and / or the transmission of the 'frame containing data symbols' by terminals such as 'Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3'", they transmit the sector sweep reference signal again. By selecting the transmission panel antenna to be used and setting the transmission beamforming, the base station and / or the terminal can obtain the effect of achieving high data reception quality.

[0187] Next, a configuration example of "Frame 1852_i containing data symbols" transmitted by terminals such as "Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3" will be described with reference to FIG. 20. Note that, for example, i is an integer of 1 or more, and in FIG. 20, the horizontal axis is assumed to be time.

[0188] As shown in FIG. 20, "Frame 1852_i containing data symbols" is assumed to be composed of a first time interval, a second time interval, a third time interval, and a fourth time interval.

[0189] Then, for example, terminal #1 of 902_1 uses the first time interval to transmit frame 2001_1 (including data symbols). Also, terminal #2 of 902_2 uses the third time interval to transmit frame 2001_2 (including data symbols).

[0190] In this way, the "frame 1852_i including data symbols" transmitted by terminals such as "terminal #1 of 902_1, terminal #2 of 902_2, terminal #3 of 902_3" performs time division, for example. Each terminal transmits a frame, and base station #1 of 901_1 can suppress interference by receiving the frames transmitted by each terminal, so high-quality data reception can be obtained.

[0191] Note that in frame 2001_1 of FIG. 20, in addition to data symbols, for example, "reference signals such as DMRS, PTRS, SRS", pilot symbols, pilot signals, preambles, symbols including control information, etc. may also be included.

[0192] Similarly, in frames such as frame 2001_1 and 2001_2 that exist in the first time interval, the second time interval, the third time interval, and the fourth time interval, in addition to data symbols, for example, "reference signals such as DMRS, PTRS, SRS", pilot symbols, pilot signals, preambles, symbols including control information, etc. may also be included.

[0193] Although FIG. 20 describes the case of time-dividing the frames transmitted by the terminals, the frames transmitted by the terminals may be frequency-divided, or space division may be performed using MU-MIMO (Multi User-MIMO (Multiple-Input Multiple-Output)).

[0194] In FIG. 14, an example regarding the occupation of terminals in the "Transmission section 1301_1 of the'sector sweep reference signal' for the first terminal, Transmission section 1301_2 of the'sector sweep reference signal' for the second terminal, Transmission section 1301_3 of the'sector sweep reference signal' for the third terminal, Transmission section 1301_4 of the'sector sweep reference signal' for the fourth terminal" shown in FIG. 13 was shown. However, in FIG. 21, an example regarding the occupation of terminals in the "Transmission section 1301_1 of the'sector sweep reference signal' for the first terminal, Transmission section 1301_2 of the'sector sweep reference signal' for the second terminal, Transmission section 1301_3 of the'sector sweep reference signal' for the third terminal, Transmission section 1301_4 of the'sector sweep reference signal' for the fourth terminal" shown in FIG. 13, which is different from FIG. 14, will be described.

[0195] In FIG. 21, those that operate in the same manner as FIGS. 13 and 14 are given the same numbers and have already been described, so the description will be omitted. Hereinafter, the differences from the description in FIG. 14 will be described.

[0196] The terminal #3 at 902_3 in FIG. 9 receives the sector sweep reference signal 1001 transmitted by the base station #1 at 901_1, and can communicate with the base station #1 at 901_1 by obtaining the "ID (identification) of the transmission panel antenna" and the "identification number (ID) of the parameters used in beamforming (directivity control)" with good reception quality.

[0197] The terminal #3 at 902_3 is assumed to estimate, as the "transmission panel antenna and parameters" with good reception quality, for example, "transmission panel antenna a3 and parameter b3".

[0198] Also, the terminal #3 of 902_3 estimates "transmission panel antenna and parameters" with good reception quality, and at the same time, obtains information on "the number of slots in which the terminal can transmit the reference signal for sector sweep (the number of terminals that can transmit the reference signal for sector sweep)" when the terminal transmits the reference signal for sector sweep. In the case of FIG. 21, the terminal #3 of 902_3 will obtain information that "the number of slots in which the terminal can transmit the reference signal for sector sweep (the number of terminals that can transmit the reference signal for sector sweep)" is 4.

[0199] In this case, the terminal #3 of 902_3 uses a random number to obtain a value of, for example, any of "0", "1", "2", "3". For example, assume that the terminal #3 of 902_3 obtains "2" using a random number. In this case, since "2" + 1 = 3, the terminal #3 of 902_3 uses the "transmission section 1301_3 of the reference signal for sector sweep for the third (= "2" + 1) terminal" in FIG. 21 to transmit the reference signal 2101_3 for sector sweep.

[0200] Note that the reference signal 2101_3 for sector sweep is assumed to include information on "transmission panel antenna and parameters" with good reception quality obtained by the terminal #3 of 902_3, that is, information on "transmission panel antenna a3 and parameter b3".

[0201] At this time, as shown in FIG. 21, the time intervals of "the reference signal 1401_2 for sector sweep transmitted by the terminal #2 of 902_2" and "the reference signal 2101_3 for sector sweep transmitted by the terminal #3 of 902_3" overlap.

[0202] Therefore, the base station #1 of 901_1 may receive "the reference signal 1401_2 for sector sweep transmitted by the terminal #2 of 902_2" and "the reference signal 2101_3 for sector sweep transmitted by the terminal #3 of 902_3" simultaneously.

[0203] In this case, the following two cases can be considered.

[0204] <Case 1> Both the "sector sweep reference signal 1401_2 transmitted by terminal #2 of 902_2" and the "sector sweep reference signal 2101_3 transmitted by terminal #3 of 902_3" have the configuration shown in FIG. 15.

[0205] At this time, since the "transmission panel antenna and beamforming parameters of terminal #2 of 902_2" with good reception quality when the base station #1 of 901_1 receives the "sector sweep reference signal 1401_2 transmitted by terminal #2 of 902_2" and the "transmission panel antenna and beamforming parameters of terminal #3 of 902_3" with good reception quality when the base station #1 of 901_1 receives the "sector sweep reference signal 1401_3 transmitted by terminal #3 of 902_3" are different, the base station #1 of 901_1 can obtain the information included in the "sector sweep reference signal 1401_2 transmitted by terminal #2 of 902_2" and the information included in the "sector sweep reference signal 2101_3 transmitted by terminal #3 of 902_3".

[0206] In this case, for example, the "feedback signal 1601_1 for the first terminal in FIG. 16 is a signal for terminal #1 of 902_1", the "feedback signal 1601_2 for the second terminal is a signal for terminal #3 of 902_3", and the "feedback signal 1601_3 for the third terminal is a signal for terminal #2 of 902_2".

[0207] Also, for example, the "modulation signal (slot) 1701_1 for the first terminal in FIG. 17 is a signal for terminal #1 of 902_1", the "modulation signal (slot) 1701_2 for the second terminal is a signal for terminal #3 of 902_3", and the "modulation signal (slot) 1701_3 for the third terminal is a signal for terminal #2 of 902_2".

[0208] By doing so, the base station #1 of 901_1 can communicate with (the terminal #1 of 902_1), the terminal #2 of 902_2, and the terminal #3 of 902_3.

[0209] <Case 2> Both the "sector sweep reference signal 1401_2 transmitted by the terminal #2 of 902_2" and the "sector sweep reference signal 2101_3 transmitted by the terminal #3 of 902_3" have the configuration shown in FIG. 15.

[0210] At this time, it is assumed that the "transmission panel antenna and beamforming parameters of the terminal #2 of 902_2 with good reception quality when the base station #1 of 901_1 receives the'sector sweep reference signal 1401_2 transmitted by the terminal #2 of 902_2'" interferes with the "transmission panel antenna and beamforming parameters of the terminal #3 of 902_3 with good reception quality when the base station #1 of 901_1 receives the'sector sweep reference signal 1401_3 transmitted by the terminal #3 of 902_3'".

[0211] <Case 2-1> The base station #1 of 901_1 may obtain either the information included in the "sector sweep reference signal 1401_2 transmitted by the terminal #2 of 902_2" or the information included in the "sector sweep reference signal 2101_3 transmitted by the terminal #3 of 902_3".

[0212] For example, it is assumed that the base station #1 of 901_1 obtains the information included in the "sector sweep reference signal 1401_2 transmitted by the terminal #2 of 902_2".

[0213] In this case, for example, the "first terminal-targeted feedback signal 1601_1 in FIG. 16 is a signal targeted at the terminal #1 of 902_1", and the "third terminal-targeted feedback signal 1601_3 is a signal targeted at the terminal #2 of 902_2".

[0214] Also, for example, assume that "the modulation signal (slot) 1701_1 addressed to the first terminal in FIG. 17 is the signal addressed to terminal #1 of 902_1" and "the modulation signal (slot) 1701_3 addressed to the third terminal is the signal addressed to terminal #2 of 902_2".

[0215] By doing so, the base station #1 of 901_1 can communicate with (terminal #1 of 902_1) and terminal #2 of 902_2.

[0216] The operation of terminal #3 of 902_3 will be described.

[0217] In the sector sweep reference signal 1851_1 of FIG. 18, assume that the state is as shown in FIG. 21. Therefore, in the frames 1803_1, 1803_2, and 1803_3 including the data symbols of FIG. 18, there will be no frames (slots) addressed to terminal #3 of 902_3.

[0218] In this case, terminal #3 of 902_3 in FIG. 9 receives the sector sweep reference signal 1801_2 of FIG. 19 transmitted by the base station #1 of 901_1, and by obtaining "the ID (identification) of the transmission panel antenna" and "the ID of the parameters used in beamforming (directional control)" with good reception quality, it can communicate with the base station #1 of 901_1.

[0219] Assume that terminal #3 of 902_3 estimates "the transmission panel antenna and parameters" with good reception quality as, for example, "transmission panel antenna a3 and parameters b3".

[0220] In addition, the terminal #3 of 902_3 estimates "transmission panel antenna and parameters" with good reception quality, and at the same time, obtains information on "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" when the terminal transmits a reference signal for sector sweep. The terminal #3 of 902_3 will obtain information that "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is 4.

[0221] In this case, the terminal #3 of 902_3 uses a random number to obtain a value of, for example, any one of "0", "1", "2", and "3". For example, assume that the terminal #3 of 902_3 generates a random number using a different seed from the previous time and obtains "3". In this case, since "3" + 1 = 4, the terminal #3 of 902_3 uses the "transmission section 1301_4 of the reference signal for sector sweep for the 4th (= "3" + 1) terminal" in FIG. 22 to transmit the reference signal 2201_3 for sector sweep.

[0222] It is assumed that the reference signal 2201_3 for sector sweep includes information on "transmission panel antenna and parameters" with good reception quality obtained by the terminal #3 of 902_3, that is, information on "transmission panel antenna a3 and parameter b3".

[0223] At this time, as shown in FIG. 22, the base station #1 of 901_1 will receive "the reference signal 2201_3 for sector sweep transmitted by the terminal #3 of 902_3", and thereafter, perform the above-described predetermined procedure, and the base station #1 of 901_1 and the terminal #3 of 902_3 will communicate with each other.

[0224] <Case 2-2> There may be a case where the base station #1 of 901_1 cannot obtain both the information included in the "sector sweep reference signal 1401_2 transmitted by the terminal #2 of 902_2" and the information included in the "sector sweep reference signal 2101_3 transmitted by the terminal #3 of 902_3".

[0225] In the sector sweep reference signal 1851_1 of FIG. 18, assuming that the state is as shown in FIG. 21, the base station #1 of 901_1 cannot obtain both the information included in the "sector sweep reference signal 1401_2 transmitted by the terminal #2 of 902_2" and the information included in the "sector sweep reference signal 2101_3 transmitted by the terminal #3 of 902_3". In this case, there will be no frames (slots) addressed to the terminal #2 of 902_2 and the terminal #3 of 902_3 in the frames 1803_1, 1803_2, and 1803_3 including the data symbols of FIG. 18.

[0226] In this case, the terminal #2 of 902_2 in FIG. 9 receives the sector sweep reference signal 1801_2 of FIG. 19 transmitted by the base station #1 of 901_1, and can communicate with the base station #1 of 901_1 by obtaining the "ID (identification) of the transmission panel antenna" and the "identification number (ID) of the parameters used in beamforming (directivity control)" with good reception quality.

[0227] Assume that the terminal #2 of 902_2 estimates, as the "transmission panel antenna and parameters" with good reception quality, for example, "transmission panel antenna a2 and parameter b2".

[0228] Also, terminal #2 of 902_2 estimates "transmission panel antenna and parameters" with good reception quality, and at the same time, obtains information on "the number of slots in which a reference signal for sector sweep can be transmitted by the terminal (the number of terminals capable of transmitting a reference signal for sector sweep)" when the terminal transmits a reference signal for sector sweep. Terminal #2 of 902_2 will obtain information that the number of slots in which a reference signal for sector sweep can be transmitted by the terminal (the number of terminals capable of transmitting a reference signal for sector sweep) is 4.

[0229] In this case, terminal #2 of 902_2 uses a random number to obtain a value such as "0", "1", "2", or "3". For example, assume that terminal #2 of 902_2 generates a random number using a different seed from the previous time and obtains "2". In this case, since "2" + 1 = 3, terminal #2 of 902_2 transmits a reference signal 1401_2 for sector sweep using the "transmission section 1301_3 of the reference signal for sector sweep for the third (= "2" + 1) terminal" in FIG. 22.

[0230] It is assumed that the reference signal 1401_2 for sector sweep includes information on "transmission panel antenna and parameters" with good reception quality obtained by terminal #2 of 902_2, that is, information on "transmission panel antenna a2 and parameter b3".

[0231] At this time, as shown in FIG. 22, base station #1 of 901_1 will receive "the reference signal 1401_2 for sector sweep transmitted by terminal #2 of 902_2", and thereafter, perform the above-described predetermined procedure, and base station #1 of 901_1 and terminal #2 of 902_2 will communicate with each other.

[0232] Similarly, the terminal #3 of 902_3 receives the sector sweep reference signal 1801_2 of FIG. 19 transmitted by the base station #1 of 901_1, and by obtaining a "transmission panel antenna ID (identification) (identification number)" and an "identification number (ID) of the parameters used in beamforming (directivity control)" with good reception quality, it is possible to communicate with the base station #1 of 901_1.

[0233] The terminal #3 of 902_3 is assumed to estimate, as "transmission panel antenna and parameters" with good reception quality, for example, "transmission panel antenna a3 and parameter b3".

[0234] Also, while estimating "transmission panel antenna and parameters" with good reception quality, the terminal #3 of 902_3 will obtain information on "the number of slots in which the reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting the reference signal for sector sweep)" when the terminal transmits the reference signal for sector sweep. The terminal #3 of 902_3 will obtain information that "the number of slots in which the reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting the reference signal for sector sweep)" is 4.

[0235] In this case, the terminal #3 of 902_3 uses a random number to obtain a value of, for example, any of "0", "1", "2", "3". For example, assume that the terminal #3 of 902_3 generates a random number using a different seed from the previous time and obtains "3". In this case, since "3" + 1 = 4, the terminal #3 of 902_3 uses the "transmission section 1301_4 of the reference signal for sector sweep for the 4th (= "3" + 1) terminal" of FIG. 22 to transmit the reference signal for sector sweep 2201_3.

[0236] Note that the sector sweep reference signal 2201_3 is assumed to include the information on the "transmission panel antenna and parameters" with good reception quality obtained by terminal #3 of 902_3, that is, the information on "transmission panel antenna a3 and parameters b3".

[0237] At this time, as shown in FIG. 22, the base station #1 of 901_1 will receive the "sector sweep reference signal 2201_3 transmitted by terminal #3 of 902_3", and thereafter, perform the aforementioned predetermined procedure, and the base station #1 of 901_1 and terminal #3 of 902_3 will communicate with each other.

[0238] By doing the above, it is possible to further reduce the collision of the sector sweep reference signals transmitted by each terminal, and thereby increase the number of sector sweep reference signals that the base station can receive, and obtain the effect of increasing the number of terminals with which the base station communicates.

[0239] As described in this embodiment, the terminal can obtain the effect of improving the communication capacity in the system composed of the base station and the terminal by transmitting the sector sweep reference signal so that the number of collision occurrences is reduced. Note that the configurations of the terminal and the base station are not limited to the configurations in FIGS. 1A, 1B, and 1C. Also, the configurations of the transmission panel antenna and the reception panel antenna are not limited to the configurations in FIGS. 3 and 4, and for example, an antenna configuration capable of generating one or more or a plurality of transmission directivities and reception directivities may be used. Also, in FIGS. 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, and 22, there are signals, frames, etc., but the names are not limited to these, and the function of the signal itself to be transmitted is important.

[0240] (Embodiment 2) In this embodiment, as a modification of Embodiment 1, an example in which a base station transmits a plurality of modulation signals (a plurality of streams) to a terminal will be described. (That is, an example in which MIMO (Multiple-Input Multiple-Output) is implemented will be described.)

[0241] FIG. 9 shows an example of a communication state in this embodiment. Since the details have already been described, the description will be omitted.

[0242] FIG. 23 shows an example of a modulation signal 2300 transmitted by base station #1 of 901_1 in FIG. 9. Those that operate in the same manner as in FIG. 10 are given the same numbers and the description will be omitted.

[0243] The sector sweep reference signal 1001 exists in the time interval from time t0 to t1.

[0244] The time interval from time t1 to t2 is the response interval of the terminal.

[0245] The feedback signal group 2302 exists in the time interval from time t2 to t3. The feedback signal group 2302 will be described later.

[0246] The frame group 2303 including data symbols exists in the time interval from time t4 to t5. The frame group 2303 including data symbols will be described later.

[0247] FIG. 11 shows an example of the sector sweep reference signal 1001 of FIG. 23 transmitted by base station #1 of FIG. 9. Since the operation of FIG. 11 has already been described, the description will be omitted.

[0248] FIG. 12 shows a configuration example of the "sector sweep reference signal 1101_i in transmission panel antenna i" of FIG. 11. Since the operation of FIG. 12 has already been described, the description will be omitted.

[0249] FIG. 13 shows an operation example in the time interval from time t1 to t2, which is the terminal response interval. Note that the operation of FIG. 13 has already been described, so the description is omitted.

[0250] FIG. 14 shows an example regarding the occupancy of the terminals of "the transmission interval 1301_1 of the reference signal for sector sweep for the first terminal, the transmission interval 1301_2 of the reference signal for sector sweep for the second terminal, the transmission interval 1301_3 of the reference signal for sector sweep for the third terminal, and the transmission interval 1301_4 of the reference signal for sector sweep for the fourth terminal" shown in FIG. 13. Note that the operation of FIG. 14 has already been described, so the different parts of the operation in this embodiment will be described.

[0251] It is assumed that the terminal #1 at 902_1 in FIG. 9 wants to receive a plurality of modulation signals from, for example, the base station #1 at 901_1. Here, it is assumed that the terminal #1 at 902_1 in FIG. 9 wants to receive two modulation signals from the base station #1 at 901_1. In this case, the terminal #1 at 902_1 in FIG. 9 receives the reference signal 1001 for sector sweep transmitted by the base station #1 at 901_1, and estimates two "transmission panel antennas and parameter numbers" with good reception quality among the transmission panel antennas of the base station #1 at 901_1.

[0252] At this time, the two "transmission panel antennas and parameter numbers" with good reception quality are named the first "transmission panel antennas and parameter numbers" and the second "transmission panel antennas and parameter numbers". And the "transmission panel antenna of the first 'transmission panel antennas and parameter numbers'" and the "transmission panel antenna of the second 'transmission panel antennas and parameter numbers'" are different.

[0253] Note that this estimation can be performed by obtaining the sector sweep reference signal 1001 and the "ID (identification number) of the transmission panel antenna" and the "identification number (ID) of the parameters used in beamforming (directivity control)" included therein.

[0254] Assume that the terminal #1 of 902_1 estimates two "transmission panel antennas and parameters" with good reception quality, for example, "transmission panel antenna a1_1 and parameter b1_1", and "transmission panel antenna a1_2 and parameter b1_2". (In the following, when explaining with reference to Fig. 24, "transmission panel antenna a1_1" is set as the transmission panel antenna 1 of 106_1 in Fig. 1A, Fig. 1B, and Fig. 1C (of the base station #1 of 901_1), and "transmission panel antenna a1_2" is set as the transmission panel antenna 2 of 106_2 in Fig. 1A, Fig. 1B, and Fig. 1C (of the base station #1 of 901_1).)

[0255] Also, when the terminal #1 of 902_1 estimates the "transmission panel antenna and parameter" with good reception quality, it will obtain the information on "the number of slots available for transmitting the sector sweep reference signal (the number of terminals capable of transmitting the sector sweep reference signal)" when the terminal transmits the sector sweep reference signal. In the case of Fig. 14, the terminal #1 of 902_1 will obtain the information that "the number of slots available for transmitting the sector sweep reference signal (the number of terminals capable of transmitting the sector sweep reference signal)" is 4.

[0256] In this case, terminal #1 of 902_1 obtains a value of either "0", "1", "2", or "3" using a random number. For example, assume that terminal #1 of 902_1 obtains "0" using a random number. In this case, since "0" + 1 = 1, terminal #1 of 902_1 uses the "sector sweep reference signal transmission section 1301_1 for the first (= "0" + 1) terminal" in FIG. 14 to transmit a sector sweep reference signal 1401_1.

[0257] Note that the sector sweep reference signal 1401_1 includes information on the "transmission panel antenna and parameters" with good reception quality obtained by terminal #1 of 902_1, that is, information on "transmission panel antenna a1_1 and parameter b1_1", and information on "transmission panel antenna a1_2 and parameter b1_2". Also, the sector sweep reference signal 1401_1 may include request information (here, "2") on the "number of modulation signals (streams) that terminal #1 of 902_1 desires to transmit to base station #1 of 901_1).

[0258] Similarly, terminal #2 of 902_2 in FIG. 9 receives the sector sweep reference signal 1001 transmitted by base station #1 of 901_1, and estimates the "transmission panel antenna and parameter number" with good reception quality among the transmission panel antennas of base station #1 of 901_1. Note that this estimation can be performed by obtaining the sector sweep reference signal 1001 and the "ID (identification) of the transmission panel antenna" and the "identification number (ID) of the parameter used in beamforming (directivity control)" included therein.

[0259] The terminal #2 of 902_2 is presumed to be, for example, "transmission panel antenna a2_1 and parameter b2_1" as "transmission panel antenna and parameter" with good reception quality. (Note that when explaining later using FIG. 24, the "transmission panel antenna a2_1" is set as the transmission panel antenna 3 of 106_1 in FIGS. 1A, 1B, and 1C (of the base station #1 of 901_1).)

[0260] Also, while presuming "transmission panel antenna and parameter" with good reception quality, the terminal #2 of 902_2 will obtain information on "the number of slots in which the terminal can transmit the reference signal for sector sweep (the number of terminals that can transmit the reference signal for sector sweep)" when the terminal transmits the reference signal for sector sweep. In the case of FIG. 14, the terminal #2 of 902_2 will obtain information that "the number of slots in which the terminal can transmit the reference signal for sector sweep (the number of terminals that can transmit the reference signal for sector sweep)" is 4.

[0261] In this case, the terminal #2 of 902_2 uses a random number to obtain a value of, for example, any one of "0", "1", "2", "3". For example, assume that the terminal #2 of 902_2 obtains "2" using a random number. In this case, since "2" + 1 = 3, the terminal #2 of 902_2 uses the "transmission section 1301_3 of the reference signal for sector sweep for the third (= "2" + 1) terminal" in FIG. 14 to transmit the reference signal 1401_2 for sector sweep.

[0262] Note that the sector sweep reference signal 1401_2 includes the information on the "transmission panel antenna and parameters" with good reception quality obtained by terminal #2 of 902_2, that is, the information on "transmission panel antenna a2 and parameters b2". This will be described later. That is, it is assumed to include the information on "transmission panel antenna a2_1 and parameters b2_1". Further, the sector sweep reference signal 1401_2 may include the request information (here, "1") on the "number of modulation signals (streams) desired to be transmitted to base station #1 of 901_1" obtained by terminal #2 of 902_2.

[0263] By doing the above, it is possible to reduce the collision of the sector sweep reference signals transmitted by each terminal, and thereby increase the number of sector sweep reference signals that the base station can receive, and obtain the effect of increasing the number of terminals with which the base station can communicate. Also, by doing as described above, it becomes possible for the base station to transmit one or a plurality of modulation signals (streams) to each terminal.

[0264] The configuration of the sector sweep reference signal 1401_i transmitted by terminal #i of 902_i described with reference to FIG. 14 will be described. For simplicity of explanation, it is assumed that terminal #i of 902_i has the configurations of FIGS. 1A, 1B, and 1C. Also, it is assumed that terminal #i of 902_i having the configurations of FIGS. 1A, 1B, and 1C has the configuration of FIG. 3 as the transmission panel antenna xi of 106_xi. However, the configuration of terminal #i of 902_i is not limited to the configurations of FIGS. 1A, 1B, and 1C, and the configuration of the transmission panel antenna xi of 106_xi of terminal #i of 902_i having the configurations of FIGS. 1A, 1B, and 1C is not limited to FIG. 3.

[0265] FIG. 11 shows an example of the sector sweep reference signal 1401_i transmitted by terminal #i of 902_i. In FIG. 11, it is assumed that the horizontal axis represents time.

[0266] For example, the terminal #i of 902_i having the configurations of FIGS. 1A, 1B, and 1C transmits the sector sweep reference signal 1101_1 in the transmission panel antenna 1 from the transmission panel antenna 1 of 106_1.

[0267] Therefore, as shown in FIG. 11, the terminal #i of 902_i having the configurations of FIGS. 1A, 1B, and 1C transmits the sector sweep reference signal 1101_xi in the transmission panel antenna xi from the transmission panel antenna xi of 106_xi. Note that xi is an integer from 1 to M.

[0268] FIG. 15 shows a configuration example of the "sector sweep reference signal 1101_xi in the transmission panel antenna xi" in FIG. 11. Note that the description of the operation in FIG. 15 has already been given, so the description is omitted.

[0269] FIG. 24 shows an example of the configuration of the feedback signal group 2302 transmitted by the base station #1 of 901_1 existing in the time interval from t2 to t3 in FIG. 23. In FIG. 24, it is assumed that the horizontal axis represents time. Also, for simplicity of explanation, it is assumed that the base station 1 of 901_1 includes four transmission panel antennas: the transmission panel antenna 1 of 106_1, the transmission panel antenna 2 of 106_2, the transmission panel antenna 3 of 106_3, and the transmission panel antenna 4 of 106_4.

[0270] In this example, since "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is 4 when a terminal transmits a reference signal for sector sweep, as shown in FIG. 24, the feedback signal 2302 includes four groups of feedback signals for terminals, namely, the first-terminal-destined feedback signal group 2400_1, the second-terminal-destined feedback signal group 2400_2, the third-terminal-destined feedback signal group 2400_3, and the fourth-terminal-destined feedback signal group 2400_4. For example, when "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is Ω, the feedback signal group 2302 may be configured to include Ω groups of feedback signals for terminals. However, Ω is an integer of 1 or more, or an integer of 2 or more.

[0271] Note that although it is described as a feedback signal group, this is because a feedback signal can be present in the transmission panel antenna 1 of 106_1, can be present in the transmission panel antenna 2 of 106_2, can be present in the transmission panel antenna 3 of 106_3, and can be present in the transmission panel antenna 4 of 106_4.

[0272] For example, as shown in FIG. 14, when the terminal #1 of 902_1 transmits the reference signal 1401_1 for sector sweep and the terminal #2 of 902_2 transmits the reference signal 1401_2 for sector sweep, the base station #1 of 901_1 uses the first-terminal-destined feedback signal group 2400_1 to transmit a feedback signal group to the terminal #1 of 902_1 and uses the third-terminal-destined feedback signal group 2400_3 to transmit a feedback signal group to the terminal #2 of 902_2.

[0273] The feedback signal group 2400_1 for the first terminal is composed of the "feedback signal (1) for terminal #1 of 902_1" 2401_1 transmitted from the transmission panel antenna 1 of 106_1 of base station #1 of 901_1, and the "feedback signal (2) for terminal #1 of 902_1" 2401_2 transmitted from the transmission panel antenna 2 of 106_2 of base station #1 of 901_1, as shown in FIG. 24.

[0274] Thus, the reason why the feedback signal group 2400_1 for the first terminal is composed of the "feedback signal (1) for terminal #1 of 902_1" 2401_1 and the "feedback signal (2) for terminal #1 of 902_1" 2401_2 is that "base station #1 of 901_1 transmits two modulation signals (streams) to terminal #1 of 902_1".

[0275] And the feedback signal group 2400_3 for the third terminal is composed of the "feedback signal for terminal #2 of 902_2" 2402_1 transmitted from the transmission panel antenna 3 of 106_3 of base station #1 of 901_1, as shown in FIG. 24.

[0276] At this time, it is assumed that the "feedback signal (1) for terminal #1 of 902_1" contains information such as the communication between terminal #1 of 902_1 and (base station #1 of 901_1) using the transmission panel antenna 1 of 106_1 is possible.

[0277] In addition, it is assumed that the "feedback signal (2) for terminal #1 of 902_1" contains information such as the communication between terminal #1 of 902_1 and (base station #1 of 901_1) using the transmission panel antenna 2 of 106_2 is possible.

[0278] Also, it is assumed that the "feedback signal for terminal #2 of 902_2" contains information such as the communication between terminal #2 of 902_2 and (base station #1 of 901_1) using the transmission panel antenna 3 of 106_3 is possible.

[0279] Based on the information of "two transmission panel antennas and parameters" of base station #1 of 901_1 with good reception quality sent by terminal #1 of 902_1, base station #1 of 901_1 will select the transmission panel antenna, set the parameters of beamforming, and transmit the feedback signal 2400_1 for the first terminal. (This is why two transmission panel antennas are used.)

[0280] Similarly, based on the information of "transmission panel antenna and parameters" of base station #1 of 901_1 with good reception quality sent by terminal #2 of 902_2, base station #1 of 901_1 will select the transmission panel antenna, set the parameters of beamforming, and transmit the feedback signal 2400_3 for the third terminal.

[0281] FIG. 25 shows an example of the configuration of the frame group 2303 including the data symbols transmitted by base station #1 of 901_1 existing in the time interval from t4 to t5 in FIG. 23. In FIG. 25, it is assumed that the horizontal axis is time.

[0282] In this example, since the number of slots capable of transmitting the reference signal for sector sweep (the number of terminals capable of transmitting the reference signal for sector sweep) when the terminal transmits the reference signal for sector sweep is 4, as shown in FIG. 25, in the frame group 2303 including data symbols, there are modulation signal (slot) groups for four terminals, such as the modulation signal (slot) group 2500_1 for the first terminal, the modulation signal (slot) group 2500_2 for the second terminal, the modulation signal (slot) group 2500_3 for the third terminal, and the modulation signal (slot) group 2500_4 for the fourth terminal. For example, when the number of slots capable of transmitting the reference signal for sector sweep (the number of terminals capable of transmitting the reference signal for sector sweep) when the terminal transmits the reference signal for sector sweep is Ω, the frame group 2303 including data symbols may be configured such that there are Ω modulation signal (slot) groups for terminals. However, Ω is an integer of 1 or more, or an integer of 2 or more.

[0283] Note that although it is named a frame group including data symbols, this is because a frame including data symbols can be present in the transmission panel antenna 1 of 106_1, and a frame including data symbols can be present in the transmission panel antenna 2 of 106_2, a frame including data symbols can be present in the transmission panel antenna 3 of 106_3, and a frame including data symbols can be present in the transmission panel antenna 4 of 106_4.

[0284] For example, as shown in FIG. 14, when the terminal #1 of 902_1 transmits the reference signal 1401_1 for sector sweep and the terminal #2 of 902_2 transmits the reference signal 1401_2 for sector sweep, the base station #1 of 901_1 uses the modulation signal (slot) group 2500_1 for the first terminal to transmit the modulation signal (slot) group to the terminal #1 of 902_1, and uses the modulation signal (slot) 2500_3 for the third terminal to transmit the modulation signal (slot) group to the terminal #2 of 902_2.

[0285] As shown in FIG. 25, the modulation signal (slot) group 2500_1 for the first terminal is composed of the "modulation signal (slot) (1) for the terminal #1 of 902_1" 2501_1 transmitted from the transmission panel antenna 1 of 106_1 of the base station #1 of 901_1, and the "modulation signal (slot) (2) for the terminal #1 of 902_1" 2501_2 transmitted from the transmission panel antenna 2 of 106_2 of the base station #1 of 901_1.

[0286] Thus, the modulation signal (slot) group 2500_1 for the first terminal is composed of the "modulation signal (slot) (1) for the terminal #1 of 902_1" and the "modulation signal (slot) (2) for the terminal #1 of 902_1" because "the base station #1 of 901_1 transmits two modulation signals (streams) to the terminal #1 of 902_1".

[0287] And, as shown in FIG. 25, the modulation signal (slot) 2500_3 for the third terminal is composed of the "modulation signal (slot) for the terminal #2 of 902_2" 2502_1 transmitted from the transmission panel antenna 3 of 106_3 of the base station #1 of 901_1.

[0288] At this time, assume that the "modulation signal (slot) (1) for the terminal #1 of 902_1" contains, for example, data symbols (data, information) for the terminal #1 of 902_1.

[0289] In addition, assume that the "modulation signal (slot) (2) for the terminal #1 of 902_1" also contains, for example, data symbols (data, information) for the terminal #1 of 902_1.

[0290] Also, assume that the "modulation signal (slot) for the terminal #2 of 902_2" contains, for example, data symbols (data, information) for the terminal #2 of 902_2.

[0291] Based on the information of "the transmission panel antenna and parameters" of base station #1 of 901_1 with good reception quality sent by terminal #1 of 902_1, base station #1 of 901_1 will select a transmission panel antenna, set the parameters of beamforming, and transmit a modulation signal group 2500_1 for the first terminal (slot for the first terminal). (This is why two transmission panel antennas are used.)

[0292] Similarly, based on the information of "the transmission panel antenna and parameters" of base station #1 of 901_1 with good reception quality sent by terminal #2 of 902_2, base station #1 of 901_1 will select a transmission panel antenna, set the parameters of beamforming, and transmit a modulation signal 2500_3 for the third terminal (slot for the first terminal).

[0293] In the modulation signal group 2500_1 for the first terminal (slot for the first terminal) in Fig. 25, in addition to data symbols, for example, "reference signals such as DMRS, PTRS, SRS", pilot symbols, pilot signals, preambles, symbols containing control information, etc. may also be included. Note that the symbols containing control information may include information on the destination terminal (ID capable of identifying the terminal), the transmission method of the modulation signal, information on the modulation method, information on the error correction coding method (code length, coding rate, etc.), information on MCS, etc.

[0294] Similarly, in the modulation signal group 2500_2 for the second terminal (slot for the second terminal), the modulation signal group 2500_3 for the third terminal (slot for the third terminal), and the modulation signal group 2500_4 for the fourth terminal (slot for the fourth terminal), in addition to data symbols, for example, "reference signals such as DMRS, PTRS, SRS", pilot symbols, pilot signals, preambles, symbols containing control information, etc. may also be included. Note that the symbols containing control information may include information on the destination terminal (ID capable of identifying the terminal), the transmission method of the modulation signal, information on the modulation method, information on the error correction coding method (code length, coding rate, etc.), information on MCS, etc.

[0295] Figure 26 shows an example of the situation when the base station #1 of 901_1 communicates with "Terminal #1 of 902_1 and Terminal #2 of 902_2" in Fig. 9. Fig. 26(A) shows an example of the transmission status of the modulation signal of the base station #1 of 901_1, and Fig. 26(B) shows an example of the transmission status of the modulation signals of "Terminal #1 of 902_1 and Terminal #2 of 902_2". In Figs. 26(A) and 26(B), it is assumed that the horizontal axis represents time. In Fig. 26, those that operate in the same manner as in Fig. 18 are assigned the same numbers.

[0296] First, the base station #1 of 901_1 transmits the sector sweep reference signal 1801_1. Since this has already been explained using Fig. 23, the explanation is omitted.

[0297] Then, terminals such as "Terminal #1 of 902_1 and Terminal #2 of 902_2" transmit the sector sweep reference signal 1851_1. Since this has already been explained using Figs. 13, 14, etc., the explanation is omitted.

[0298] The base station #1 of 901_1 transmits the feedback signal group 2602_1. Since this has already been explained using Fig. 24, the explanation is omitted.

[0299] After that, the base station #1 of 901_1 transmits "the frame group 2603_1 including data symbols". Since this has already been explained using Fig. 25, the explanation is omitted. (Therefore, the "frame 2603_1 including data symbols" can be considered as, for example, a downlink frame.)

[0300] Then, terminals such as "Terminal #1 of 902_1 and Terminal #2 of 902_2" transmit "the frame group 2652_1 including data symbols". The configuration of this frame will be explained later using Fig. 28. (Therefore, the "frame group 2652_1 including data symbols" can be considered as, for example, an uplink frame.)

[0301] Next, base station #1 of 901_1 transmits "frame group 2603_2 including data symbols". The method of configuring "frame group 2603_2 including data symbols" is as described with reference to FIG. 24.

[0302] Then, terminals such as "terminal #1 of 902_1 and terminal #2 of 902_2" transmit "frame group 2652_2 including data symbols". The configuration of this frame will be described later with reference to FIG. 28.

[0303] FIG. 27 shows an example of the transmission status of the modulation signal of base station #1 of 901_1 after FIG. 26 and the transmission status of the modulation signal of terminals such as "terminal #1 of 902_1 and terminal #2 of 902_2". In FIG. 27, those that operate in the same manner as in FIG. 18 are assigned the same numbers.

[0304] FIG. 27(A) shows an example of the transmission status of the modulation signal of base station #1 of 901_1 and is a time continuation of the transmission status of the modulation signal of base station #1 of 901_1 in FIG. 26(A).

[0305] FIG. 27(B) shows an example of the transmission status of the modulation signal of "terminal #1 of 902_1 and terminal #2 of 902_2" and is a time continuation of the transmission status of the modulation signal of "terminal #1 of 902_1, terminal #2 of 902_2, and terminal #3 of 902_3" in FIG. 26(B).

[0306] In FIGS. 27(A) and 27(B), it is assumed that the horizontal axis represents time.

[0307] After FIGS. 26(A) and (B), base station #1 of 901_1 transmits "frame group 2603_3 including data symbols". The method of configuring "frame group 2603_2 including data symbols" is as described with reference to FIG. 25.

[0308] Then, terminals such as "Terminal #1 of 902_1, Terminal #2 of 902_2" transmit "Frame group 2652_3 containing data symbols". The configuration of this frame will be described later with reference to FIG. 28.

[0309] Next, Base Station #1 of 901_1 transmits Sector Sweep Reference Signal 1801_2. Since this has already been described with reference to FIG. 23, the description is omitted.

[0310] Then, terminals such as "Terminal #1 of 902_1, Terminal #2 of 902_2" transmit Sector Sweep Reference Signal 1851_2. Since this has already been described with reference to FIGS. 13, 14, etc., the description is omitted.

[0311] Base Station #1 of 901_1 transmits Feedback Signal Group 2602_2. Since this has already been described with reference to FIG. 24, the description is omitted.

[0312] After that, Base Station #1 of 901_1 transmits "Frame group 2603_4 containing data symbols". Since this has already been described with reference to FIG. 25, the description is omitted.

[0313] Then, terminals such as "Terminal #1 of 902_1, Terminal #2 of 902_2" transmit "Frame group 2652_4 containing data symbols". The configuration of this frame will be described later with reference to FIG. 28.

[0314] Thus, before "transmitting the 'frame group including data symbols' of base station #1 of 901_1 and / or transmitting the 'frame group including data symbols' of terminals such as 'terminal #1 of 902_1, terminal #2 of 902_2'", base station #1 of 901_1 and the terminals transmit a sector sweep reference signal, and after "transmitting the 'frame group including data symbols' of base station #1 of 901_1 and / or transmitting the 'frame group including data symbols' of terminals such as 'terminal #1 of 902_1, terminal #2 of 902_2'", they transmit the sector sweep reference signal again. By selecting the transmission panel antenna to be used and setting the transmission beamforming, the base station and / or terminal can obtain the effect of being able to obtain high data reception quality.

[0315] Next, a configuration example of the "frame group 2652_i including data symbols" transmitted by terminals such as "terminal #1 of 902_1, terminal #2 of 902_2" will be described with reference to FIG. 28. Note that, for example, i is an integer of 1 or more, and in FIG. 28, the horizontal axis is assumed to be time.

[0316] As shown in FIG. 28, it is assumed that the "frame group 2652_i including data symbols" is composed of a first time interval, a second time interval, a third time interval, and a fourth time interval.

[0317] And, for example, terminal #1 of 902_1 uses the first time interval to transmit a frame group 2801_1 (including data symbols). Also, terminal #2 of 902_2 uses the third time interval to transmit a frame group 2801_2 (including data symbols).

[0318] Note that, similar to the case where base station #1 of 901_1 transmits a plurality of modulation signals with reference to FIG. 25, for example, when terminal #1 of 902_1 transmits the frame group 2801_1 to base station #1 of 901_1, terminal #1 of 902_1 may transmit a plurality of modulation signals (slots) to base station #1 of 901_1 using a plurality of transmission panel antennas.

[0319] Also, when the terminal #1 of 902_1 transmits the frame group 2801_1 to the base station #1 of 901_1, the terminal #1 of 902_1 may transmit one modulation signal (slot) to the base station #1 of 901_1.

[0320] In this way, the frame group 2652_i including data symbols transmitted by terminals such as "terminal #1 of 902_1, terminal #2 of 902_2" performs time division, for example. Each terminal transmits the frame group, and the base station #1 of 901_1 can suppress interference by receiving the frame groups transmitted by each terminal, so that high-quality data reception can be obtained.

[0321] In addition, in the frame group 2801_1 of FIG. 28, in addition to data symbols, for example, "reference signals such as DMRS, PTRS, SRS", pilot symbols, pilot signals, preambles, symbols including control information, etc. may be included.

[0322] Similarly, in frames existing in the first time interval, the second time interval, the third time interval, and the fourth time interval, such as the frame groups 2801_1 and 2801_2, in addition to data symbols, for example, "reference signals such as DMRS, PTRS, SRS", pilot symbols, pilot signals, preambles, symbols including control information, etc. may be included.

[0323] Although FIG. 28 illustrates the case where the frame group transmitted by the terminal is time-divided, the frame group transmitted by the terminal may be frequency-divided, or space division may be performed using MU-MIMO.

[0324] As described in this embodiment, the terminal can obtain the effect of improving the communication capacity in a system composed of a base station and a terminal by transmitting a reference signal for sector sweep so that the number of collision occurrences decreases. Note that the configurations of the terminal and the base station are not limited to those shown in FIGS. 1A, 1B, and 1C. Also, the configurations of the transmission panel antenna and the reception panel antenna are not limited to those shown in FIGS. 3 and 4, and for example, any antenna configuration that can generate one or more or a plurality of transmission directivities and reception directivities may be used. Further, in FIGS. 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, signals, frames, etc. exist, but the names are not limited to these, and the function of the signal itself to be transmitted is important.

[0325] (Embodiment 3) In this embodiment, modified examples of Embodiment 1 and Embodiment 2 will be described. Note that hereinafter, the figures shown in Embodiment 1 and / or Embodiment 2 may be used for the description. In this case, a part of the description of the figures shown in Embodiment 1 and / or Embodiment 2 may be omitted.

[0326] FIG. 29 shows an example of the communication state in this embodiment. In FIG. 29, those that operate in the same manner as in FIG. 9 are given the same reference numerals and the description thereof is omitted.

[0327] In FIG. 29, the base station #1 of 901_1 communicates with the terminal #4 of 2902_4, the terminal #5 of 2902_5, and the terminal #6 of 2902_6 in addition to the terminal #1 to the terminal #3.

[0328] FIG. 30 shows an example of the modulation signal 3000 transmitted by the base station #1 of 901_1 in FIG. 29. Those that operate in the same manner as in FIG. 10 are given the same reference numerals and the description thereof is omitted.

[0329] In the time interval from time t0 to t1, the sector sweep reference signal 1001 exists.

[0330] The time interval from time t1 to t2 is the response interval of the terminal.

[0331] In the time interval from time t2 to t3, the feedback signal group 3002 exists. Note that the feedback signal group 3002 will be described later.

[0332] In the time interval from time t4 to time t5, the frame group 3003 including data symbols exists. Note that the frame group 3003 including data symbols will be described later.

[0333] FIG. 11 shows an example of the sector sweep reference signal 1001 of FIG. 30 transmitted by the base station #1 of FIG. 29. Note that the operation of FIG. 11 has already been described, so the description is omitted.

[0334] FIG. 12 shows a configuration example of the "sector sweep reference signal 1101_i in the transmission panel antenna i" of FIG. 11. Note that the operation of FIG. 12 has already been described, so the description is omitted.

[0335] FIG. 13 shows an operation example of the time interval from time t1 to t2, which is the terminal response interval. Note that the operation of FIG. 13 has already been described, so the description is omitted.

[0336] FIG. 14 shows an example regarding the occupancy of the terminals of the "transmission section 1301_1 of the sector sweep reference signal for the first terminal, transmission section 1301_2 of the sector sweep reference signal for the second terminal, transmission section 1301_3 of the sector sweep reference signal for the third terminal, transmission section 1301_4 of the sector sweep reference signal for the fourth terminal" shown in FIG. 13. Note that the operation of FIG. 14 has already been described in Embodiment 1, Embodiment 2, etc., so the description is omitted.

[0337] FIG. 15 shows a configuration example of the "sector sweep reference signal 1101_xi in the transmission panel antenna xi" in FIG. 11. The operation of FIG. 15 has already been described, so the description is omitted.

[0338] FIGS. 31A, 31B, 31C, and 31D show an example of the configuration of the feedback signal group 3002 transmitted by the base station #1 of 901_1 existing in the time interval from t2 to t3 in FIG. 30. In FIGS. 31A, 31B, 31C, and 31D, the horizontal axis is assumed to be time. Also, for simplicity of explanation, the base station #1 of 901_1 is assumed to include four transmission panel antennas: the transmission panel antenna 1 of 106_1, the transmission panel antenna 2 of 106_2, the transmission panel antenna 3 of 106_3, and the transmission panel antenna 4 of 106_4.

[0339] FIG. 31A is a diagram related to the feedback signal of the transmission panel antenna 1 of 106_1 among the feedback signal group 3002. FIG. 31B is a diagram related to the feedback signal of the transmission panel antenna 2 of 106_2 among the feedback signal group 3002. FIG. 31C is a diagram related to the feedback signal of the transmission panel antenna 3 of 106_3 among the feedback signal group 3002. FIG. 31D is a diagram related to the feedback signal of the transmission panel antenna 4 of 106_4 among the feedback signal group 3002.

[0340] In the example of Fig. 31A, since "the number of slots in which a reference signal for sector sweep can be transmitted by a terminal (the number of terminals capable of transmitting a reference signal for sector sweep)" is 4, as shown in Fig. 31A, among the feedback signal groups 3002 of 3100_1, the feedback signal of transmission panel antenna 1 includes four groups of feedback signals for terminals, namely, the feedback signal group 3101_11 for the first terminal, the feedback signal group 3101_12 for the second terminal, the feedback signal group 3101_13 for the third terminal, and the feedback signal group 3101_14 for the fourth terminal. For example, when "the number of slots in which a reference signal for sector sweep can be transmitted by a terminal (the number of terminals capable of transmitting a reference signal for sector sweep)" is Ω, the feedback signal of transmission panel antenna 1 among the feedback signal groups 3002 of 3100_1 may be configured such that there are Ω groups of feedback signals for terminals. However, Ω is an integer of 1 or more, or an integer of 2 or more.

[0341] Although it is described by naming it as a feedback signal group, this is because it is possible to have a feedback signal for transmission panel antenna 1 of 106_1, and it is also possible to have a feedback signal for transmission panel antenna 2 of 106_2, a feedback signal for transmission panel antenna 3 of 106_3, and a feedback signal for transmission panel antenna 4 of 106_4.

[0342] In the example of FIG. 31B, since "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is 4 when the terminal transmits a reference signal for sector sweep, as shown in FIG. 31B, among the feedback signal groups 3002 of 3100_2, the feedback signal of the transmission panel antenna 2 includes four terminal-destined feedback signal groups such as the first-terminal-destined feedback signal group 3101_21, the second-terminal-destined feedback signal group 3101_22, the third-terminal-destined feedback signal group 3101_23, and the fourth-terminal-destined feedback signal group 3101_24. For example, when "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is Ω when the terminal transmits a reference signal for sector sweep, the feedback signal of the transmission panel antenna 2 among the feedback signal groups 3002 of 3100_2 may be configured such that there are Ω terminal-destined feedback signal groups. However, Ω is an integer of 1 or more, or an integer of 2 or more.

[0343] In the example of FIG. 31C, since "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is 4 when the terminal transmits a reference signal for sector sweep, as shown in FIG. 31C, among the feedback signal groups 3002 of the transmission panel antenna 3 in the feedback signal group 3100_3, there are four feedback signal groups for terminals, namely, the feedback signal group 3101_31 for the first terminal, the feedback signal group 3101_32 for the second terminal, the feedback signal group 3101_33 for the third terminal, and the feedback signal group 3101_34 for the fourth terminal. For example, when "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is Ω when the terminal transmits a reference signal for sector sweep, the feedback signal of the transmission panel antenna 3 among the feedback signal groups 3002 of 3100_3 may be configured such that there are Ω feedback signal groups for terminals. However, Ω is an integer of 1 or more, or an integer of 2 or more.

[0344] In the example of FIG. 31D, since "the number of slots in which a reference signal for sector sweep can be transmitted by a terminal (the number of terminals capable of transmitting a reference signal for sector sweep)" is 4, as shown in FIG. 31D, among the feedback signal groups 3002 of 3100_4, the feedback signal of transmission panel antenna 4 includes four terminal-destined feedback signal groups such as the first terminal-destined feedback signal group 3101_41, the second terminal-destined feedback signal group 3101_42, the third terminal-destined feedback signal group 3101_43, and the fourth terminal-destined feedback signal group 3101_44. For example, when "the number of slots in which a reference signal for sector sweep can be transmitted by a terminal (the number of terminals capable of transmitting a reference signal for sector sweep)" is Ω, the feedback signal of transmission panel antenna 4 among the feedback signal groups 3002 of 3100_4 may have a configuration in which there are Ω terminal-destined feedback signal groups. However, Ω is an integer of 1 or more, or an integer of 2 or more.

[0345] FIGS. 32A, 32B, 32C, and 32D show an example of the configuration of a frame group 3003 including data symbols transmitted by base station #1 of 901_1 existing in the time interval from t4 to t5 in FIG. 30. In FIGS. 32A, 32B, 32C, and 32D, it is assumed that the horizontal axis represents time.

[0346] FIG. 32A is a diagram related to the frame of transmission panel antenna 1 of 106_1 among the frame group 3003 including data symbols. FIG. 32B is a diagram related to the frame of transmission panel antenna 2 of 106_2 among the frame group 3003 including data symbols. FIG. 32C is a diagram related to the frame of transmission panel antenna 3 of 106_3 among the frame group 3003 including data symbols. FIG. 32D is a diagram related to the frame of transmission panel antenna 4 of 106_4 among the frame group 3003 including data symbols.

[0347] In the example of FIG. 32A, since the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep) is 4 when the terminal transmits a reference signal for sector sweep, as shown in FIG. 32A, in the frame of transmission panel antenna 1 among the frame group 3003 including the data symbol 3200_1, there are modulation signals (slots) for four terminals, such as the modulation signal (slot for the first terminal) 3201_11 for the first terminal, the modulation signal (slot for the second terminal) 3201_12 for the second terminal, the modulation signal (slot for the third terminal) 3201_13 for the third terminal, and the modulation signal (slot for the fourth terminal) 3201_14 for the fourth terminal. For example, when the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep) is Ω when the terminal transmits a reference signal for sector sweep, the configuration may be such that there is a group of modulation signals (slots) for Ω terminals in the frame of transmission panel antenna 1 among the frame group 3003 including the data symbol 3200_1. However, Ω is an integer of 1 or more, or an integer of 2 or more.

[0348] Note that although it is named a frame group including data symbols, this is because it is possible to have a frame including data symbols for transmission panel antenna 1 of 106_1, and it is possible to have a frame including data symbols for transmission panel antenna 2 of 106_2, it is possible to have a frame including data symbols for transmission panel antenna 3 of 106_3, and it is possible to have a frame including data symbols for transmission panel antenna 4 of 106_4.

[0349] In the example of Fig. 32B, since "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is 4 when the terminal transmits a reference signal for sector sweep, as shown in Fig. 32B, in the frame of transmission panel antenna 2 among the frame group 3003 including the data symbol 3200_2, there are modulation signals (slots) addressed to four terminals, such as the modulation signal (slot for the first terminal) 3201_21 addressed to the first terminal, the modulation signal (slot for the second terminal) 3201_22 addressed to the second terminal, the modulation signal (slot for the third terminal) 3201_23 addressed to the third terminal, and the modulation signal (slot for the fourth terminal) 3201_24 addressed to the fourth terminal. For example, when "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is Ω when the terminal transmits a reference signal for sector sweep, the frame of transmission panel antenna 2 among the frame group 3003 including the data symbol 3200_2 may have a configuration in which there is a group of modulation signals (slots) addressed to Ω terminals. However, Ω is an integer of 1 or more, or an integer of 2 or more.

[0350] In the example of FIG. 32C, since "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is 4 when the terminal transmits a reference signal for sector sweep, as shown in FIG. 32C, in the frame of the transmission panel antenna 3 among the frame groups 3003 including the data symbols 3200_3, there are modulation signals (slots) for four terminals, such as the modulation signal for the first terminal (the first-terminal slot) 3201_31, the modulation signal for the second terminal (the second-terminal slot) 3201_32, the modulation signal for the third terminal (the third-terminal slot) 3201_33, and the modulation signal for the fourth terminal (the fourth-terminal slot) 3201_34. For example, when "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is Ω when the terminal transmits a reference signal for sector sweep, the frame of the transmission panel antenna 3 among the frame groups 3003 including the data symbols 3200_3 may be configured such that there are Ω groups of modulation signals (slots) for terminals. However, Ω is an integer of 1 or more, or an integer of 2 or more.

[0351] In the example of FIG. 32D, since the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep) when the terminal transmits a reference signal for sector sweep is 4, as shown in FIG. 32D, in the frame of the transmission panel antenna 4 among the frame groups 3003 including 3200_4 data symbols, there are modulation signals (slots) for four terminals, such as the modulation signal (slot for the first terminal) 3201_41 for the first terminal, the modulation signal (slot for the second terminal) 3201_42 for the second terminal, the modulation signal (slot for the third terminal) 3201_43 for the third terminal, and the modulation signal (slot for the fourth terminal) 3201_44 for the fourth terminal. For example, when the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep) when the terminal transmits a reference signal for sector sweep is Ω, the configuration may be such that there are Ω groups of modulation signals (slots) for terminals in the frame of the transmission panel antenna 4 among the frame groups 3003 including 3200_4 data symbols. However, Ω is an integer of 1 or more, or an integer of 2 or more.

[0352] FIG. 33 is a diagram showing an example of terminal occupancy in the “reference signal for sector sweep” transmission section for the terminal according to the present embodiment. Note that FIG. 33 is an example of terminal occupancy in the time section from t1 to t2 shown in FIG. 13, in the “transmission section 1301_1 of the reference signal for sector sweep for the first terminal, transmission section 1301_2 of the reference signal for sector sweep for the second terminal, transmission section 1301_3 of the reference signal for sector sweep for the third terminal, transmission section 1301_4 of the reference signal for sector sweep for the fourth terminal”.

[0353] For example, as shown in FIG. 33, terminal #1 of 902_1 transmits the sector sweep reference signal 3301_1 to the "sector sweep reference signal" transmission section for the first terminal of 1301_1. Terminal #2 of 902_2 transmits the sector sweep reference signal 3301_2 to the "sector sweep reference signal" transmission section for the first terminal of 1301_1. Terminal #3 of 902_3 transmits the sector sweep reference signal 3301_3 to the "sector sweep reference signal" transmission section for the first terminal of 1301_1. Terminal #4 of 2902_4 transmits the sector sweep reference signal 3301_4 to the "sector sweep reference signal" transmission section for the third terminal of 1301_3. Terminal #5 of 2902_5 transmits the sector sweep reference signal 3301_5 to the "sector sweep reference signal" transmission section for the fourth terminal of 1301_4. Assume that terminal #6 of 2902_6 transmits the sector sweep reference signal 3301_6.

[0354] Regarding the information transmitted by the sector sweep reference signal 3301_1 transmitted by terminal #1 of 902_1, it is as described in Embodiment 1, Embodiment 2, etc.

[0355] Regarding the information transmitted by the sector sweep reference signal 3301_2 transmitted by terminal #2 of 902_2, it is as described in Embodiment 1, Embodiment 2, etc.

[0356] Regarding the information transmitted by the sector sweep reference signal 3301_3 transmitted by terminal #3 of 902_3, it is as described in Embodiment 1, Embodiment 2, etc.

[0357] Regarding the information transmitted by the sector sweep reference signal 3301_1 transmitted by terminal #4 of 2902_4, it is as described in Embodiment 1, Embodiment 2, etc.

[0358] Regarding the information transmitted by the reference signal 3301_5 for sector sweep transmitted by the terminal #5 of 2902_5, it is as described in Embodiment 1, Embodiment 2, etc.

[0359] Regarding the information transmitted by the reference signal 3301_6 for sector sweep transmitted by the terminal #6 of 2902_6, it is as described in Embodiment 1, Embodiment 2, etc.

[0360] For the time interval from t2 to t3 when the time interval from t1 to t2 is the example shown in FIG. 33, it will be described with reference to FIGS. 34A to 34D.

[0361] Then, as shown in FIG. 34A, the base station #1 of 901_1 transmits the "feedback signal for terminal #1 of 3401_1" as the "feedback signal for the first terminal in the feedback signal of the transmission panel antenna 1 among the feedback signal group 3002 of 3100_1".

[0362] Also, as shown in FIG. 34A, the base station #1 of 901_1 transmits the "feedback signal for terminal #4 of 3401_4" as the "feedback signal for the third terminal in the feedback signal of the transmission panel antenna 1 among the feedback signal group 3002 of 3100_1".

[0363] And, as shown in FIG. 34B, the base station #1 of 901_1 transmits the "feedback signal for terminal #2 of 3401_2" as the "feedback signal for the first terminal in the feedback signal of the transmission panel antenna 2 among the feedback signal group 3002 of 3100_2".

[0364] Also, as shown in FIG. 34B, the base station #1 of 901_1 transmits the "feedback signal for terminal #5 of 3401_5" as the "feedback signal for the fourth terminal in the feedback signal of the transmission panel antenna 2 among the feedback signal group 3002 of 3100_2".

[0365] As shown in FIG. 34C, the base station #1 of 901_1 transmits the "feedback signal for terminal #3 of 3401_3" as the "feedback signal for the first terminal of 3101_31" in the "feedback signal of the transmission panel antenna 3 among the feedback signal groups 3002 of 3100_3".

[0366] As shown in FIG. 34D, the base station #1 of 901_1 transmits the "feedback signal for terminal #6 of 3401_6" as the "feedback signal for the second terminal of 3101_42" in the "feedback signal of the transmission panel antenna 4 among the feedback signal groups 3002 of 3100_4".

[0367] At this time, it is assumed that the "feedback signal for terminal #1 of 3401_1" in FIG. 34A contains information such as that the terminal #1 of 902_1 can communicate (with the base station #1 of 901_1) using the transmission panel antenna 1 of 106_1.

[0368] Also, it is assumed that the "feedback signal for terminal #4 of 3401_4" in FIG. 34A contains information such as that the terminal #4 of 2902_4 can communicate (with the base station #1 of 901_1) using the transmission panel antenna 1 of 106_1.

[0369] It is assumed that the "feedback signal for terminal #2 of 3401_2" in FIG. 34B contains information such as that the terminal #2 of 902_2 can communicate (with the base station #1 of 901_1) using the transmission panel antenna 2 of 106_2.

[0370] Also, it is assumed that the "feedback signal for terminal #5 of 3401_5" in FIG. 34B contains information such as that the terminal #5 of 2902_5 can communicate (with the base station #1 of 901_1) using the transmission panel antenna 2 of 106_2.

[0371] For the "Feedback signal for terminal #3 of 3401_3" in FIG. 34C, for example, it is assumed that the information that terminal #3 of 902_3 can communicate using transmission panel antenna 3 of 106_3 (with base station #1 of 901_1) is included.

[0372] For the "Feedback signal for terminal #6 of 3401_6" in FIG. 34D, for example, it is assumed that the information that terminal #6 of 2902_6 can communicate using transmission panel antenna 4 of 106_4 (with base station #1 of 901_1) is included.

[0373] In addition, other information may be included in each feedback signal for the terminal. Examples thereof are as described in Embodiment 1, Embodiment 2, etc.

[0374] Based on the sector sweep reference signal 3301_1 in FIG. 33 transmitted by terminal #1 of 902_1, base station #1 of 901_1 selects a transmission panel antenna (selects transmission panel antenna 1 as in FIG. 34A), sets the parameters of beamforming, and transmits a feedback signal 3401_1 for terminal #1.

[0375] Based on the sector sweep reference signal 3301_2 in FIG. 33 transmitted by terminal #2 of 902_2, base station #1 of 901_1 selects a transmission panel antenna (selects transmission panel antenna 2 as in FIG. 34B), sets the parameters of beamforming, and transmits a feedback signal 3401_2 for terminal #2.

[0376] Based on the sector sweep reference signal 3301_3 in FIG. 33 transmitted by terminal #3 of 902_3, base station #1 of 901_1 selects a transmission panel antenna (selects transmission panel antenna 3 as in FIG. 34C), sets the parameters of beamforming, and transmits a feedback signal 3401_3 for terminal #3.

[0377] Based on the sector sweep reference signal 3301_4 transmitted by terminal #4 of 2902_4, base station #1 of 901_1 will select a transmission panel antenna (select transmission panel antenna 1 as shown in FIG. 34A), set the parameters of beamforming, and transmit a feedback signal 3401_4 addressed to terminal #4.

[0378] Based on the sector sweep reference signal 3301_5 transmitted by terminal #5 of 2902_5, base station #1 of 901_1 will select a transmission panel antenna (select transmission panel antenna 2 as shown in FIG. 34B), set the parameters of beamforming, and transmit a feedback signal 3401_5 addressed to terminal #5.

[0379] Based on the sector sweep reference signal 3301_6 transmitted by terminal #6 of 2902_6, base station #1 of 901_1 will select a transmission panel antenna (select transmission panel antenna 4 as shown in FIG. 34D), set the parameters of beamforming, and transmit a feedback signal 3401_6 addressed to terminal #6.

[0380] Next, for the time interval from t4 to t5 when the time interval from t2 to t3 is the example shown in FIGS. 34A to 34D, FIGS. 35A to 35D will be used for explanation.

[0381] For example, as shown in FIG. 35A, the base station #1 of 901_1 transmits the modulation signal (slot) addressed to terminal #1 of 3501_1 as the modulation signal (slot) addressed to the first terminal of 3201_11 in the "frame of transmission panel antenna 1 among the frame group 3003 including the data symbols of 3200_1". Note that the modulation signal (slot) addressed to terminal #1 of 3501_1 contains the data addressed to terminal #1 of 902_1. Also, the modulation signal (slot) addressed to terminal #1 of 3501_1 is transmitted using transmission panel antenna 1. And the setting method of the transmission method of the modulation signal (slot) addressed to terminal #1 of 3501_1 is as described in Embodiment 1, Embodiment 2, etc. For example, as described in Embodiment 2, a plurality of modulation signals (slots) may be assigned to one terminal address.

[0382] Also, as shown in FIG. 35A, the base station #1 of 901_1 transmits the modulation signal (slot) addressed to terminal #4 of 3501_4 as the modulation signal (slot) addressed to the third terminal of 3201_13 in the "frame of transmission panel antenna 1 among the frame group 3003 including the data symbols of 3200_1". Note that the modulation signal (slot) addressed to terminal #4 of 3501_4 contains the data addressed to terminal #4 of 2902_4. Also, the modulation signal (slot) addressed to terminal #4 of 3501_4 is transmitted using transmission panel antenna 1. And the setting method of the transmission method of the modulation signal (slot) addressed to terminal #4 of 3501_4 is as described in Embodiment 1, Embodiment 2, etc. For example, as described in Embodiment 2, a plurality of modulation signals (slots) may be assigned to one terminal address.

[0383] As shown in Fig. 35B, the base station #1 of 901_1 transmits the modulation signal (slot) addressed to terminal #2 of 3501_2 as the modulation signal (slot) addressed to the first terminal of 3201_21 in the "frame of transmission panel antenna 2 among the frame group 3003 including the data symbols of 3200_2". Note that the modulation signal (slot) addressed to terminal #2 of 3501_2 contains the data addressed to terminal #2 of 902_2. Also, the modulation signal (slot) addressed to terminal #2 of 3501_2 is transmitted using transmission panel antenna 2. And the setting method of the transmission method of the modulation signal (slot) addressed to terminal #2 of 3501_2 is as described in Embodiment 1, Embodiment 2, etc. For example, as described in Embodiment 2, a plurality of modulation signals (slots) may be assigned to one terminal address.

[0384] Also, as shown in Fig. 35B, the base station #1 of 901_1 transmits the modulation signal (slot) addressed to terminal #5 of 3501_5 as the modulation signal (slot) addressed to the fourth terminal of 3201_24 in the "frame of transmission panel antenna 2 among the frame group 3003 including the data symbols of 3200_2". Note that the modulation signal (slot) addressed to terminal #5 of 3501_5 contains the data addressed to terminal #5 of 2902_5. Also, the modulation signal (slot) addressed to terminal #5 of 3501_5 is transmitted using transmission panel antenna 2. And the setting method of the transmission method of the modulation signal (slot) addressed to terminal #5 of 3501_5 is as described in Embodiment 1, Embodiment 2, etc. For example, as described in Embodiment 2, a plurality of modulation signals (slots) may be assigned to one terminal address.

[0385] As shown in FIG. 35C, base station #1 of 901_1 transmits the modulation signal (slot) addressed to terminal #3 of 3501_3 as the modulation signal (slot) addressed to the first terminal in the frame of transmission panel antenna 3 among the frame group 3003 including the data symbols of 3200_3. Note that the modulation signal (slot) addressed to terminal #3 of 3501_3 contains the data addressed to terminal #3 of 902_3. Further, the modulation signal (slot) addressed to terminal #3 of 3501_3 is transmitted using transmission panel antenna 3. The setting method of the transmission method of the modulation signal (slot) addressed to terminal #3 of 3501_3 is as described in Embodiment 1, Embodiment 2, etc. For example, as described in Embodiment 2, a plurality of modulation signals (slots) may be assigned to one terminal address.

[0386] As shown in FIG. 35D, base station #1 of 901_1 transmits the modulation signal (slot) addressed to terminal #6 of 3501_6 as the modulation signal (slot) addressed to the second terminal in the frame of transmission panel antenna 4 among the frame group 3003 including the data symbols of 3200_4. Note that the modulation signal (slot) addressed to terminal #6 of 3501_6 contains the data addressed to terminal #6 of 2902_6. Further, the modulation signal (slot) addressed to terminal #6 of 3501_6 is transmitted using transmission panel antenna 4. The setting method of the transmission method of the modulation signal (slot) addressed to terminal #6 of 3501_6 is as described in Embodiment 1, Embodiment 2, etc. For example, as described in Embodiment 2, a plurality of modulation signals (slots) may be assigned to one terminal address.

[0387] In the "Modulation Signal (Slot) for Terminal #1 of 3501_1" in Fig. 35A, in addition to data symbols, "reference signals such as DMRS, PTRS, and SRS", pilot symbols, pilot signals, preambles, symbols containing control information, etc. may also be included. Note that the symbols containing control information may include information on the destination terminal (ID capable of identifying the terminal), the transmission method of the modulation signal, information on the modulation method, information on the error correction coding method (code length, coding rate, etc.), information on MCS, etc.

[0388] Also, in the "Modulation Signal (Slot) for Terminal #4 of 3501_4" in Fig. 35A, in addition to data symbols, "reference signals such as DMRS, PTRS, and SRS", pilot symbols, pilot signals, preambles, symbols containing control information, etc. may also be included. Note that the symbols containing control information may include information on the destination terminal (ID capable of identifying the terminal), the transmission method of the modulation signal, information on the modulation method, information on the error correction coding method (code length, coding rate, etc.), information on MCS, etc.

[0389] In the "Modulation Signal (Slot) for Terminal #2 of 3501_2" in Fig. 35B, in addition to data symbols, "reference signals such as DMRS, PTRS, and SRS", pilot symbols, pilot signals, preambles, symbols containing control information, etc. may also be included. Note that the symbols containing control information may include information on the destination terminal (ID capable of identifying the terminal), the transmission method of the modulation signal, information on the modulation method, information on the error correction coding method (code length, coding rate, etc.), information on MCS, etc.

[0390] Also, in the "Modulation Signal (Slot) for Terminal #5 of 3501_5" in FIG. 35B, in addition to data symbols, "reference signals such as DMRS, PTRS, and SRS", pilot symbols, pilot signals, preambles, symbols including control information, etc. may be included. Note that the symbols including control information may include information on the destination terminal (ID capable of identifying the terminal), the transmission method of the modulation signal, information on the modulation method, information on the error correction coding method (code length, coding rate, etc.), MCS information, etc.

[0391] In the "Modulation Signal (Slot) for Terminal #3 of 3501_3" in FIG. 35C, in addition to data symbols, "reference signals such as DMRS, PTRS, and SRS", pilot symbols, pilot signals, preambles, symbols including control information, etc. may be included. Note that the symbols including control information may include information on the destination terminal (ID capable of identifying the terminal), the transmission method of the modulation signal, information on the modulation method, information on the error correction coding method (code length, coding rate, etc.), MCS information, etc.

[0392] In the "Modulation Signal (Slot) for Terminal #6 of 3501_6" in FIG. 35D, in addition to data symbols, "reference signals such as DMRS, PTRS, and SRS", pilot symbols, pilot signals, preambles, symbols including control information, etc. may be included. Note that the symbols including control information may include information on the destination terminal (ID capable of identifying the terminal), the transmission method of the modulation signal, information on the modulation method, information on the error correction coding method (code length, coding rate, etc.), MCS information, etc.

[0393] As described above, the base station #1 of 901_1 can obtain the effect of improving the data transmission efficiency in the system by allocating symbols for the destination terminal to the modulation signals transmitted for each transmission panel antenna. Also, the terminal can obtain the effect of improving the communication capacity in the system composed of the base station and the terminal by transmitting the reference signal for sector sweep so that the number of collision occurrences is reduced.

[0394] Next, the communication status in an example of the communication state shown in FIG. 29 will be described. The communication status in an example of the communication state shown in FIG. 29 may be the same as that in FIGS. 26 and 27. Hereinafter, an example of the communication status will be described with reference to FIGS. 26 and 27.

[0395] FIG. 26 shows an example of the situation when, in FIG. 29, the base station #1 of 901_1 is communicating with "the terminal #1 of 902_1, the terminal #2 of 902_2, the terminal #3 of 902_3, the terminal #4 of 2902_4, the terminal #5 of 2902_5, and the terminal #6 of 2902_6". FIG. 26(A) shows an example of the transmission status of the modulation signal of the base station #1 of 901_1, and FIG. 26(B) shows an example of the transmission status of the modulation signal of "the terminal #1 of 902_1, the terminal #2 of 902_2, the terminal #3 of 902_3, the terminal #4 of 2902_4, the terminal #5 of 2902_5, and the terminal #6 of 2902_6". In FIGS. 26(A) and 26(B), it is assumed that the horizontal axis represents time. In FIG. 26, those that operate in the same manner as in FIG. 18 are given the same numbers.

[0396] First, the base station #1 of 901_1 transmits the sector sweep reference signal 1801_1. Since this has already been described with reference to FIG. 30, the description will be omitted.

[0397] Then, terminals such as "the terminal #1 of 902_1, the terminal #2 of 902_2, the terminal #3 of 902_3, the terminal #4 of 2902_4, the terminal #5 of 2902_5, and the terminal #6 of 2902_6" transmit the sector sweep reference signal 1851_1. Since this has already been described with reference to FIGS. 13 and 14, the description will be omitted.

[0398] The base station #1 of 901_1 transmits the feedback signal group 2602_1. Since this has already been described with reference to FIGS. 31A, 31B, 31C, and 31D, the description will be omitted.

[0399] After that, base station #1 of 901_1 transmits "frame group 2603_1 including data symbols". Note that this has already been explained with reference to FIGS. 32A, 32B, 32C, and 32D, so the explanation is omitted here. (Therefore, "frame 2603_1 including data symbols" can be considered as a downlink frame, for example.)

[0400] Then, terminals such as "terminal #1 of 902_1, terminal #2 of 902_2, terminal #3 of 902_3, terminal #4 of 2902_4, terminal #5 of 2902_5, terminal #6 of 2902_6" transmit "frame group 2652_1 including data symbols". Note that the configuration of this frame will be described later with reference to FIG. 36. (Therefore, "frame group 2652_1 including data symbols" can be considered as an uplink frame, for example.)

[0401] Next, base station #1 of 901_1 transmits "frame group 2603_2 including data symbols". The method of configuring "frame group 2603_2 including data symbols" is as described with reference to FIGS. 32A, 32B, 32C, and 32D.

[0402] Then, terminals such as "terminal #1 of 902_1, terminal #2 of 902_2, terminal #3 of 902_3, terminal #4 of 2902_4, terminal #5 of 2902_5, terminal #6 of 2902_6" transmit "frame group 2652_2 including data symbols". Note that the configuration of this frame will be described later with reference to FIG. 36.

[0403] FIG. 27 shows an example of the transmission status of the modulation signal of base station #1 of 901_1 after FIG. 26 and the transmission status of the modulation signal of terminals such as "terminal #1 of 902_1, terminal #2 of 902_2, terminal #3 of 902_3, terminal #4 of 2902_4, terminal #5 of 2902_5, terminal #6 of 2902_6". In FIG. 27, those that operate in the same manner as in FIG. 18 are given the same numbers.

[0404] FIG. 27(A) shows an example of the transmission status of the modulation signal of base station #1 of 901_1, which is a time continuation of the transmission status of the modulation signal of base station #1 of 901_1 in FIG. 26(A).

[0405] FIG. 27(B) shows an example of the transmission status of the modulation signals of "Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3, Terminal #4 of 2902_4, Terminal #5 of 2902_5, Terminal #6 of 2902_6", which is a time continuation of the transmission status of the modulation signals of "Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3, Terminal #4 of 2902_4, Terminal #5 of 2902_5, Terminal #6 of 2902_6" in FIG. 26(B).

[0406] Note that in FIGS. 27(A) and 27(B), the horizontal axis is assumed to be time.

[0407] After FIGS. 26(A) and (B), base station #1 of 901_1 transmits "Frame group 2603_3 including data symbols". The method of constructing "Frame group 2603_2 including data symbols" is as described with reference to FIGS. 32A, 32B, 32C, and 32D.

[0408] Then, terminals such as "Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3, Terminal #4 of 2902_4, Terminal #5 of 2902_5, Terminal #6 of 2902_6" transmit "Frame group 2652_3 including data symbols". The configuration of this frame will be described later with reference to FIG. 36.

[0409] Next, base station #1 of 901_1 transmits the sector sweep reference signal 1801_2. Since this has already been described with reference to FIG. 30, the description is omitted.

[0410] Then, terminals such as "Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3, Terminal #4 of 2902_4, Terminal #5 of 2902_5, Terminal #6 of 2902_6" transmit the sector sweep reference signal 1851_2. Note that this has already been explained using Figures 13, 14, etc., so the explanation is omitted.

[0411] Base station #1 of 901_1 transmits the feedback signal group 2602_2. Note that this has already been explained using Figures 31A, 31B, 31C, and 31D, so the explanation is omitted.

[0412] After that, base station #1 of 901_1 transmits the "frame group 2603_4 including data symbols". Note that this has already been explained using Figures 32A, 32B, 32C, and 32D, so the explanation is omitted.

[0413] Then, terminals such as "Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3, Terminal #4 of 2902_4, Terminal #5 of 2902_5, Terminal #6 of 2902_6" transmit the "frame group 2652_4 including data symbols". The configuration of this frame will be explained later using Figure 36.

[0414] Thus, before the transmission of "a frame group including data symbols" of base station #1 of 901_1 and / or the transmission of "a frame group including data symbols" of terminals such as "terminal #1 of 902_1, terminal #2 of 902_2, terminal #3 of 902_3, terminal #4 of 2902_4, terminal #5 of 2902_5, terminal #6 of 2902_6", base station #1 of 901_1 and the terminals may transmit a sector sweep reference signal. Also, after the transmission of "a frame group including data symbols" of base station #1 of 901_1 and / or the transmission of "a frame group including data symbols" of terminals such as "terminal #1 of 902_1, terminal #2 of 902_2, terminal #3 of 902_3, terminal #4 of 2902_4, terminal #5 of 2902_5, terminal #6 of 2902_6", base station #1 of 901_1 and the terminals may transmit a sector sweep reference signal again. By selecting the transmission panel antenna to be used and setting the transmission beamforming, the base station and / or the terminal can obtain the effect of obtaining high data reception quality.

[0415] Next, a configuration example of "frame group 2652_i including data symbols" transmitted by terminals such as "terminal #1 of 902_1, terminal #2 of 902_2, terminal #3 of 902_3, terminal #4 of 2902_4, terminal #5 of 2902_5, terminal #6 of 2902_6" will be described with reference to FIG. 36. Note that, for example, i is an integer of 1 or more, and in FIG. 36, the horizontal axis is assumed to be time.

[0416] As shown in FIG. 36, it is assumed that "frame group 2652_i including data symbols" is composed of a first time interval, a second time interval, a third time interval, and a fourth time interval.

[0417] Then, for example, terminal #1 of 902_1 uses the first time interval to transmit a frame group 3601_1 (including data symbols). Also, terminal #2 of 902_2 uses the third time interval to transmit a frame group 3601_2 (including data symbols). Terminal #3 of 902_3 uses the first time interval to transmit a frame group 3601_3 (including data symbols). Terminal #4 of 2902_4 uses the third time interval to transmit a frame group 3601_4 (including data symbols). Terminal #5 of 2902_5 uses the fourth time interval to transmit a frame group 3601_5 (including data symbols). Terminal #6 of 2902_6 uses the second time interval to transmit a frame group 3601_6 (including data symbols).

[0418] Note that in FIG. 36, for example, in the first time interval, there are a frame group 3601_1 transmitted by terminal #1 and a frame 3601_3 transmitted by terminal #3. However, if the "panel antenna used by the base station of 901_1 to communicate with terminal #1" and the "panel antenna used by the base station of 901_1 to communicate with terminal #3" are different, the frame group 3601_1 and the frame 3601_3 can reduce interference with each other. Also, in the third time interval, there are a frame group 3601_2 transmitted by terminal #2 and a frame 3601_4 transmitted by terminal #4. However, if the "panel antenna used by the base station of 901_1 to communicate with terminal #2" and the "panel antenna used by the base station of 901_1 to communicate with terminal #4" are different, the frame group 3601_2 and the frame 3601_4 can reduce interference with each other.

[0419] Also, each terminal may transmit a modulation signal (slot) using a plurality of time intervals in FIG. 36, or each terminal may transmit a plurality of modulation signals (slots) in a certain time interval. This is as described in Embodiment 1, Embodiment 2, etc.

[0420] In this way, for the "frame group 2652_i including data symbols" transmitted by terminals such as "terminal #1 of 902_1 and terminal #2 of 902_2", for example, time division is performed, and each terminal transmits a frame group. The base station #1 of 901_1 can suppress interference by receiving the frame groups transmitted by each terminal, so high-quality data reception can be obtained. Also, at the base station #1 of 901_1, depending on the usage method of the panel antenna, it is possible to create a situation where even if multiple terminals transmit modulation signals (slots) at the same time, the interference between them is small.

[0421] In the frame groups 3601_1, 3601_2, 3601_3, 3601_4, 3601_5, and 3601_6 in FIG. 36, in addition to data symbols, for example, "reference signals such as DMRS, PTRS, and SRS", pilot symbols, pilot signals, preambles, symbols including control information, etc. may also be included.

[0422] In FIG. 36, the case where the frame group transmitted by the terminal is time-divided and space-divided using MU-MIMO is described, but the frame group transmitted by the terminal may also be frequency-divided.

[0423] FIG. 37A is a modified example of FIG. 35A. In FIG. 37A, the same numbers are assigned to those that operate in the same manner as in FIG. 35A. FIG. 37B is a modified example of FIG. 35B. In FIG. 37B, the same numbers are assigned to those that operate in the same manner as in FIG. 35B. FIG. 37C is a modified example of FIG. 35C. In FIG. 37C, the same numbers are assigned to those that operate in the same manner as in FIG. 35C. FIG. 37D is a modified example of FIG. 35D. In FIG. 37D, the same numbers are assigned to those that operate in the same manner as in FIG. 37D.

[0424] The difference between FIG. 37A and FIG. 35A is that in FIG. 35A, the modulation signal (slot) 3501_1 addressed to terminal #1 is composed of 1 slot, while in FIG. 37A, the modulation signal (slot) 3501_1 addressed to terminal #1 is composed of 2 slots. This is because in FIG. 35A, there are free slots that have not been allocated, and in FIG. 37A, the free slots are effectively utilized, so the data transmission efficiency will be improved. Note that the effective utilization of free slots is the same for FIGS. 37B, 37C, and 37D. Therefore, the method of using slots is not limited to FIGS. 35A, 35B, 35C, 35D, 37A, 37B, 37C, and 37D.

[0425] Also, focusing on the second slot in each of FIGS. 37A, 37B, 37C, and 37D, in FIG. 37A, there is a modulation signal (slot) 3501_1 addressed to terminal #1, in FIG. 37B, there is a modulation signal (slot) 3501_2 addressed to terminal #2, in FIG. 37C, there is a modulation signal (slot) 3501_3 addressed to terminal #3, and in FIG. 37D, there is a modulation signal (slot) 3501_6 addressed to terminal #6. For example, in this way, in a certain time interval such as the second slot in each of FIGS. 37A, 37B, 37C, and 37D, there may be modulation signals (slots) with different destinations for each panel antenna. In this case, the same frequency (the same frequency band) may be used by the four panel antennas, or the same frequency (the same frequency band) may not be used.

[0426] Note that when the same frequency (the same frequency band) is used, it can be considered as transmission by MU-MIMO. For example, when the directivity is different for each panel antenna, even if MU-MIMO is used, the effect of reducing interference with each other can be obtained. (Note that the related transmission method is also described in Embodiment 2.)

[0427] Also, when the base station #1 of 901_1 transmits a modulated signal for each panel antenna, for example, the modulated signal transmitted by panel antenna 1 and the modulated signal transmitted by panel antenna 2 exist in the same time interval, and the frequency (frequency band) of the modulated signal transmitted by panel antenna 1 and the frequency (frequency band) of the modulated signal transmitted by panel antenna 2 may be the same or partially common.

[0428] For example, when transmitting a modulated signal from each panel antenna, the following Case 3-1, Case 3-2, and Case 3-3 can be considered.

[0429] Case 3-1: When the base station #1 of 901_1 is equipped with a plurality of panel antennas and transmits a modulated signal from each panel antenna, in a certain time interval, a set of modulated signals with the same or partially common frequency (frequency band) may exist.

[0430] As another method, the frequency (frequency band) of the modulated signal transmitted by the base station #1 of 901_1 using panel antenna 1 and the frequency (frequency band) of the modulated signal transmitted by panel antenna 2 may be different.

[0431] Case 3-2: When the base station #1 of 901_1 is equipped with a plurality of panel antennas and transmits a modulated signal from each panel antenna, a set of modulated signals with different frequencies (frequency bands) may exist.

[0432] Furthermore, the frequency (frequency band) of the modulated signal transmitted by the base station #1 of 901_1 using panel antenna 1 and the frequency (frequency band) of the modulated signal transmitted by panel antenna 2 may be the same, and these two modulated signals may be time-division multiplexed.

[0433] Case 3-3: Base station #1 of 901_1 is equipped with a plurality of panel antennas. When transmitting modulation signals from each panel antenna, there may be a set of modulation signals with the same frequency (frequency band) and time-division multiplexed.

[0434] For example, when base station #1 of 901_1 has the configurations shown in FIGS. 1A, 1B, and 1C, the modulation signals may be generated and transmitted from the panel antennas so that, according to control signal 100, "there exists a case of 3-1", and / or "there exists a case of 3-2", and / or "there exists a case of 3-3". However, although the configuration of control signal 100 is shown as an output from the third processing unit, it is not limited to this configuration. For example, control signal 100 may be an output from other internal sources or a signal from an external source.

[0435] As described in this embodiment, the terminal can obtain the effect of improving the communication capacity in a system composed of a base station and a terminal by transmitting a reference signal for sector sweep so that the number of collision occurrences is reduced. Note that the configurations of the terminal and the base station are not limited to the configurations shown in FIGS. 1A, 1B, and 1C. Also, the configurations of the transmitting panel antenna and the receiving panel antenna are not limited to the configurations shown in FIGS. 3 and 4. For example, an antenna configuration capable of generating one or more or a plurality of transmitting directivities and receiving directivities may be used. Also, although there are signals, frames, etc. in each figure, the names are not limited to these, and the function of the signal itself to be transmitted is important.

[0436] (Embodiment 4) In this embodiment, configuration examples of modulation signals, frames, frame groups, etc. that may be applied in the examples of Embodiment 1, Embodiment 2, Embodiment 3, and Embodiment 5 to be described later will be explained. Note that in the following, the figures shown in Embodiment 1, Embodiment 2, and Embodiment 3 may be used for the explanation. In this case, part of the explanation of the figures shown in Embodiment 1, Embodiment 2, and Embodiment 3 may be omitted.

[0437] For example, in the present embodiment, configuration examples of a modulation signal, a frame, a frame group, etc. are described for cases where a base station and a terminal communicate as shown in FIGS. 18 and 19, or where a base station and a terminal communicate as shown in FIGS. 26 and 27.

[0438] For example, in Embodiment 1, when a base station and a terminal communicate as shown in FIGS. 18 and 19, it was described that the base station and the terminal select a panel antenna using the sector sweep reference signal 1801_1, the sector sweep reference signal 1851_1, and the feedback signal 1802_1, and also select the next panel antenna using the sector sweep reference signal 1801_2, the sector sweep reference signal 1851_2, and the feedback signal 1802_2.

[0439] Also, in Embodiment 2 and Embodiment 3, when a base station and a terminal communicate as shown in FIGS. 26 and 27, it was described that the base station and the terminal select a panel antenna using the sector sweep reference signal 1801_1, the sector sweep reference signal 1851_1, and the feedback signal group 2602_1, and also select the next panel antenna using the sector sweep reference signal 1801_2, the sector sweep reference signal 1851_2, and the feedback signal group 2602_2.

[0440] Hereinafter, a case of changing the parameter settings for beamforming will be described in "frames 1803_1, 1803_2, 1803_3, 1803_4, etc. including data symbols in FIGS. 18 and 19, and frames 1852_1, 1852_2, 1852_3, 1852_4, etc. including data symbols", and "frame groups 2603_1, 2603_2, 2603_3, 2603_4, etc. including data symbols in FIG. 26, and frame groups 2652_1, 2652_2, 2652_3, 2652_4, etc. including data symbols". Note that it is assumed that the panel antenna is not changed in these frames and frame groups.

[0441] FIG. 38 shows an example of the configuration of the "modulation signal (slot) addressed to the i-th terminal" 3800 transmitted by the base station in FIGS. 17, 25, 32A, 32B, 32C, 32D, 35A, 35B, 35C, 35D, 37A, 37B, 37C, and 37D. Note that i is an integer of 1 or more.

[0442] As shown in FIG. 38, the "modulation signal (slot) addressed to the i-th terminal" 3800 is assumed to be composed of, for example, a first reference symbol (first reference signal) 3801, a control information symbol 3802, a data symbol 3803, and a second reference symbol (second reference signal) 3804.

[0443] The first reference symbol 3801 is a symbol for demodulating the data symbol 3803, and is, for example, a symbol for performing channel estimation, frequency offset estimation, phase distortion (phase noise) estimation, signal detection, etc. Note that the first reference symbol 3801 may be, for example, DMRS.

[0444] The control information symbol 3802 is assumed to contain at least information regarding the data symbol 3803. The control information symbol 3802 is assumed to contain, for example, information on the transmission method used to transmit the data symbol 3803, information on the modulation method, information on the error correction coding method, etc.

[0445] At this time, the control information symbol 3802 may include information on the beamforming parameters used by the base station (which may be parameters to be used in the future). Further, the control information symbol 3802 may include information on whether the base station has changed or not changed the beamforming parameters.

[0446] The data symbol 3803 is a symbol for transmitting data.

[0447] The second reference symbol 3804 is a symbol for the terminal to estimate the state of the modulation signal transmitted by the base station. The terminal will estimate the suitable parameters for the beamforming of the base station and the suitable parameters for the beamforming of the terminal using this symbol. Note that the information estimated here may be fed back to the base station. (For example, the information estimated here may be included in the control information symbol 3902 in FIGS. 39A and 39B described later.) Note that the second reference symbol 3804 is for realizing a search for suitable directivity. The directivity may be changed symbol by symbol or for a plurality of symbols.

[0448] FIG. 39A shows an example of the configuration of the "frame, or frame group" 3900 transmitted by the terminal in FIGS. 20, 28, and 36.

[0449] As shown in FIG. 39A, the "frame, or frame group" 3900 is assumed to be composed of, for example, a third reference symbol (third reference signal) 3901, a control information symbol 3902, a data symbol 3903, and a fourth reference symbol (second reference signal) 3904.

[0450] The third reference symbol 3901 is a symbol for demodulating the data symbol 3903, and is assumed to be a symbol for performing, for example, channel estimation, frequency offset estimation, phase distortion (phase noise) estimation, signal detection, etc. Note that the third reference symbol 3901 may be, for example, DMRS.

[0451] It is assumed that the control information symbol 3902 contains at least information regarding the data symbol 3903. It is assumed that the control information symbol 3802 contains, for example, information on the transmission method used to transmit the data symbol 3903, information on the modulation method, and information on the error correction coding method.

[0452] At this time, the control information symbol 3902 may contain information on the beamforming parameters used by the terminal (which may be parameters to be used in the future). Also, the control information symbol 3902 may contain information on whether the terminal has changed or not changed the beamforming parameters.

[0453] The data symbol 3903 is a symbol for transmitting data.

[0454] The fourth reference symbol 3904 is a symbol for the base station to estimate the state of the modulation signal transmitted by the terminal. The base station will use this symbol to estimate the suitable parameters for the beamforming of the terminal and the suitable parameters for the beamforming of the base station. Note that the information estimated here may be fed back to the terminal. (For example, the information estimated here may be included in the control information symbol 3802 in FIG. 38.) Note that the fourth reference symbol 3904 may change the directivity symbol by symbol or for a plurality of symbols in order to realize a search for a suitable directivity.

[0455] FIG. 39B shows a configuration example different from that of FIG. 39A of the "frame, or frame group" 3900 transmitted by the terminal in FIGS. 20, 28, and 36.

[0456] The difference between FIG. 39B and FIG. 39A is that the fourth reference symbol 3904 does not exist. In this case, the base station and the terminal will not perform the operation using the fourth reference symbol 3904 described above.

[0457] As described above, after antenna selection in the base station and the terminal, parameters are changed one or more times for directivity control, that is, by increasing the frequency of parameter update for directivity control compared to the frequency of antenna selection, the reception quality of data can be improved, and thereby, the effect that the data transmission efficiency in the system is improved can be obtained.

[0458] Note that the configurations of FIGS. 38, 39A, and 39B are merely examples, and the configuration method is not limited thereto. For example, in FIGS. 38, 39A, and 39B, other symbols may be included, and each symbol may include other symbols. Also, the order of symbol arrangement is not limited to the examples of FIGS. 38, 39A, and 39B.

[0459] Also, when the base station and the terminal communicate as in "the base station and the terminal communicate as in FIGS. 18 and 19" or "the base station and the terminal communicate as in FIGS. 26 and 27", the frequency of the modulation signal transmitted by the base station and the frequency transmitted by the terminal may be the same, may be partially common, or may be different. However, it is not limited to the examples in this description. And the timing at which the base station transmits the modulation signal and the timing at which the terminal transmits the modulation signal are not limited to the examples of "FIGS. 18 and 19 (TDM (Time Division Multiplexing), TDD)" and "FIGS. 26 and 27 (TDM, TDD)". For example, a method other than "TDM, TDD" may be used.

[0460] (Embodiment 5) In this embodiment, a modification of Embodiment 3 will be described. Note that, hereinafter, the drawings shown in any of Embodiments 1, 2, 3, and 4 may be cited for the description. In this case, a part of the description of the drawings shown in any of Embodiments 1, 2, 3, and 4 may be omitted.

[0461] FIG. 40 shows an example of the communication state in this embodiment. In FIG. 40, those that operate in the same manner as FIGS. 9 and 29 are given the same reference numerals.

[0462] In FIG. 40, it is assumed that the base station #1 of 901_1 is communicating with "the terminal #1 of 902_1, the terminal #2 of 902_2, the terminal #3 of 902_3, the terminal #4 of 2902_4, the terminal #5 of 2902_5, and the terminal #6 of 2902_6". This is as described in Embodiment 3, and since the communication procedure, communication method, etc. are described in Embodiment 3, the description will be omitted.

[0463] In FIG. 40, furthermore, there is a base station #2 of 4001_2, and the base station #2 of 4001_2 is communicating with "the terminal #1 of 902_1, the terminal #2 of 902_2, and the terminal #3 of 902_3". Hereinafter, the operation in this regard will be described in detail.

[0464] Note that the base station #2 of 4001_2 may have the same configuration as the base station #1 of 901_1. For example, the base station #2 of 4001_2 may include four transmission panel antennas: the transmission panel antenna 1 of 106_1, the transmission panel antenna 2 of 106_2, the transmission panel antenna 3 of 106_3, and the transmission panel antenna 4 of 106_4. Also, the base station #2 of 4001_2 may be configured to include "one or a plurality of" "transmission antennas or transmission panel antennas".

[0465] Figure 30 shows an example of the modulation signal 3000 transmitted by base station #2 of 4001_2 in Figure 40. Note that those operating in the same manner as in Figure 10 are given the same numbers and their descriptions are omitted.

[0466] In the time interval from time t0 to t1, the sector sweep reference signal 1001 exists.

[0467] The time interval from time t1 to t2 is the response interval of the terminal.

[0468] In the time interval from time t2 to t3, the feedback signal group 3002 exists. Note that the feedback signal group 3002 will be described later.

[0469] In the time interval from time t4 to time t5, the frame group 3003 including data symbols exists. Note that the frame group 3003 including data symbols will be described later.

[0470] Figure 11 shows an example of the sector sweep reference signal 1001 of Figure 30 transmitted by base station #2 of 4001_2 in Figure 40. Note that the operation of Figure 11 has already been described and thus its description is omitted.

[0471] Figure 12 shows a configuration example of the "sector sweep reference signal 1101_i in transmission panel antenna i" of Figure 11. Note that the operation of Figure 12 has already been described and thus its description is omitted.

[0472] Figure 13 shows an example of the operation in the time interval from time t1 to t2, which is the terminal response interval. Note that the operation of Figure 13 has already been described and thus its description is omitted.

[0473] FIG. 14 shows an example of the occupancy of the terminals in the "transmission section 1301_1 of the'sector sweep reference signal' for the first terminal, transmission section 1301_2 of the'sector sweep reference signal' for the second terminal, transmission section 1301_3 of the'sector sweep reference signal' for the third terminal, and transmission section 1301_4 of the'sector sweep reference signal' for the fourth terminal" shown in FIG. 13. Note that the operation of FIG. 14 has already been described in Embodiment 1, Embodiment 2, etc., so the description is omitted.

[0474] FIG. 15 shows a configuration example of the "sector sweep reference signal 1101_xi in the transmission panel antenna xi" in FIG. 11. Note that the operation of FIG. 15 has already been described, so the description is omitted.

[0475] FIGS. 31A, 31B, 31C, and 31D show an example of the configuration of the feedback signal group 3002 transmitted by the base station #2 of 4001_2 existing in the time interval from t2 to t3 in FIG. 30. In FIGS. 31A, 31B, 31C, and 31D, it is assumed that the horizontal axis represents time. Also, for the sake of simplicity, it is assumed that the base station #2 of 4001_2 includes four transmission panel antennas: the transmission panel antenna 1 of 106_1, the transmission panel antenna 2 of 106_2, the transmission panel antenna 3 of 106_3, and the transmission panel antenna 4 of 106_4.

[0476] FIG. 31A is a diagram related to the feedback signal of the transmission panel antenna 1 of 106_1 among the feedback signal group 3002. FIG. 31B is a diagram related to the feedback signal of the transmission panel antenna 2 of 106_2 among the feedback signal group 3002. FIG. 31C is a diagram related to the feedback signal of the transmission panel antenna 3 of 106_3 among the feedback signal group 3002. FIG. 31D is a diagram related to the feedback signal of the transmission panel antenna 4 of 106_4 among the feedback signal group 3002.

[0477] In the example of FIG. 31A, since the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep) when a terminal transmits a reference signal for sector sweep is 4, as shown in FIG. 31A, among the feedback signal groups 3002 of 3100_1, the feedback signal of transmission panel antenna 1 includes four terminal-destined feedback signal groups such as the first terminal-destined feedback signal group 3101_11, the second terminal-destined feedback signal group 3101_12, the third terminal-destined feedback signal group 3101_13, and the fourth terminal-destined feedback signal group 3101_14. Note that, for example, when the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep) when a terminal transmits a reference signal for sector sweep is Ω, the feedback signal of transmission panel antenna 1 among the feedback signal groups 3002 of 3100_1 may have a configuration in which there are Ω terminal-destined feedback signal groups. However, Ω is an integer of 1 or more, or an integer of 2 or more.

[0478] Although it is described by naming it as a feedback signal group, this is because it is possible to have a feedback signal for transmission panel antenna 1 of 106_1, and it is also possible to have a feedback signal for transmission panel antenna 2 of 106_2, it is possible to have a feedback signal for transmission panel antenna 3 of 106_3, and it is possible to have a feedback signal for transmission panel antenna 4 of 106_4.

[0479] In the example of Fig. 31B, since "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is 4 when the terminal transmits a reference signal for sector sweep, as shown in Fig. 31B, among the feedback signal groups 3002 of 3100_2, the feedback signal of the transmission panel antenna 2 includes four terminal-destined feedback signal groups such as the first terminal-destined feedback signal group 3101_21, the second terminal-destined feedback signal group 3101_22, the third terminal-destined feedback signal group 3101_23, and the fourth terminal-destined feedback signal group 3101_24. Note that, for example, when "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is Ω when the terminal transmits a reference signal for sector sweep, the feedback signal of the transmission panel antenna 2 among the feedback signal groups 3002 of 3100_2 may be configured such that there are Ω terminal-destined feedback signal groups. However, Ω is an integer of 1 or more, or an integer of 2 or more.

[0480] In the example of FIG. 31C, since "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is 4 when the terminal transmits a reference signal for sector sweep, as shown in FIG. 31C, among the feedback signal groups 3002 of the transmission panel antenna 3 in the feedback signal group 3100_3, there are four terminal-destined feedback signal groups, such as the first terminal-destined feedback signal group 3101_31, the second terminal-destined feedback signal group 3101_32, the third terminal-destined feedback signal group 3101_33, and the fourth terminal-destined feedback signal group 3101_34. For example, when "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is Ω when the terminal transmits a reference signal for sector sweep, the feedback signal of the transmission panel antenna 3 among the feedback signal groups 3002 of 3100_3 may be configured such that there are Ω terminal-destined feedback signal groups. However, Ω is an integer of 1 or more, or an integer of 2 or more.

[0481] In the example of FIG. 31D, since "the number of slots in which a reference signal for sector sweep can be transmitted by a terminal (the number of terminals capable of transmitting a reference signal for sector sweep)" is 4, as shown in FIG. 31D, among the feedback signal groups 3002 of 3100_4, the feedback signal of the transmission panel antenna 4 includes four terminal-destined feedback signal groups such as the first terminal-destined feedback signal group 3101_41, the second terminal-destined feedback signal group 3101_42, the third terminal-destined feedback signal group 3101_43, and the fourth terminal-destined feedback signal group 3101_44. For example, when "the number of slots in which a reference signal for sector sweep can be transmitted by a terminal (the number of terminals capable of transmitting a reference signal for sector sweep)" is Ω, the feedback signal of the transmission panel antenna 4 among the feedback signal groups 3002 of 3100_4 may have a configuration in which there are Ω terminal-destined feedback signal groups. However, Ω is an integer of 1 or more, or an integer of 2 or more.

[0482] FIGS. 32A, 32B, 32C, and 32D show an example of the configuration of a frame group 3003 including data symbols transmitted by the base station #2 of 4001_2 existing in the time interval from t4 to t5 in FIG. 30. In FIGS. 32A, 32B, 32C, and 32D, it is assumed that the horizontal axis represents time.

[0483] FIG. 32A is a diagram related to the frame of the transmission panel antenna 1 of 106_1 among the frame group 3003 including data symbols. FIG. 32B is a diagram related to the frame of the transmission panel antenna 2 of 106_2 among the frame group 3003 including data symbols. FIG. 32C is a diagram related to the frame of the transmission panel antenna 3 of 106_3 among the frame group 3003 including data symbols. FIG. 32D is a diagram related to the frame of the transmission panel antenna 4 of 106_4 among the frame group 3003 including data symbols.

[0484] In the example of FIG. 32A, since the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep) when the terminal transmits a reference signal for sector sweep is 4, as shown in FIG. 32A, in the frame of transmission panel antenna 1 among the frame group 3003 including the data symbol 3200_1, there are modulation signals (slots) for four terminals, such as the modulation signal (slot for the first terminal) 3201_11 for the first terminal, the modulation signal (slot for the second terminal) 3201_12 for the second terminal, the modulation signal (slot for the third terminal) 3201_13 for the third terminal, and the modulation signal (slot for the fourth terminal) 3201_14 for the fourth terminal. For example, when the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep) when the terminal transmits a reference signal for sector sweep is Ω, the frame of transmission panel antenna 1 among the frame group 3003 including the data symbol 3200_1 may have a configuration in which there is a group of modulation signals (slots) for Ω terminals. However, Ω is an integer of 1 or more, or an integer of 2 or more.

[0485] Note that although it is named a frame group including data symbols, this is because it is possible to have a frame including the data symbol for transmission panel antenna 1 of 106_1, and it is possible to have a frame including the data symbol for transmission panel antenna 2 of 106_2, it is possible to have a frame including the data symbol for transmission panel antenna 3 of 106_3, and it is possible to have a frame including the data symbol for transmission panel antenna 4 of 106_4.

[0486] In the example of FIG. 32B, since "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is 4 when the terminal transmits a reference signal for sector sweep, as shown in FIG. 32B, in the frame of the transmission panel antenna 2 among the frame group 3003 including the data symbol 3200_2, there are modulation signals (slots) for four terminals, such as the modulation signal for the first terminal (the first-terminal slot) 3201_21, the modulation signal for the second terminal (the second-terminal slot) 3201_22, the modulation signal for the third terminal (the third-terminal slot) 3201_23, and the modulation signal for the fourth terminal (the fourth-terminal slot) 3201_24. For example, when "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is Ω when the terminal transmits a reference signal for sector sweep, the frame of the transmission panel antenna 2 among the frame group 3003 including the data symbol 3200_2 may have a configuration in which a group of modulation signals (slots) for Ω terminals exists. However, Ω is an integer of 1 or more, or an integer of 2 or more.

[0487] In the example of FIG. 32C, since "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is 4 when the terminal transmits a reference signal for sector sweep, as shown in FIG. 32C, in the frame of the transmission panel antenna 3 among the frame group 3003 including the data symbols 3200_3, there are modulation signals (slots) addressed to four terminals, such as the modulation signal (slot for the first terminal) 3201_31 addressed to the first terminal, the modulation signal (slot for the second terminal) 3201_32 addressed to the second terminal, the modulation signal (slot for the third terminal) 3201_33 addressed to the third terminal, and the modulation signal (slot for the fourth terminal) 3201_34 addressed to the fourth terminal. For example, when "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is Ω when the terminal transmits a reference signal for sector sweep, the frame of the transmission panel antenna 3 among the frame group 3003 including the data symbols 3200_3 may be configured such that there are Ω groups of modulation signals (slots) addressed to terminals. However, Ω is an integer of 1 or more, or an integer of 2 or more.

[0488] In the example of FIG. 32D, since "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is 4 when the terminal transmits a reference signal for sector sweep, as shown in FIG. 32D, in the frame of transmission panel antenna 4 among the frame group 3003 including 3200_4 data symbols, there are modulation signals (slots) for four terminals, such as the modulation signal (slot for the first terminal) 3201_41 for the first terminal, the modulation signal (slot for the second terminal) 3201_42 for the second terminal, the modulation signal (slot for the third terminal) 3201_43 for the third terminal, and the modulation signal (slot for the fourth terminal) 3201_44 for the fourth terminal. For example, when "the number of slots in which a reference signal for sector sweep can be transmitted (the number of terminals capable of transmitting a reference signal for sector sweep)" is Ω when the terminal transmits a reference signal for sector sweep, the configuration may be such that there is a group of modulation signals (slots) for Ω terminals in the frame of transmission panel antenna 4 among the frame group 3003 including 3200_4 data symbols. However, Ω is an integer of 1 or more, or an integer of 2 or more.

[0489] FIG. 41 is a diagram showing an example of terminal occupancy in the "reference signal for sector sweep" transmission section for the terminal according to the present embodiment. Note that FIG. 41 is an example of terminal occupancy in the time section from t1 to t2 shown in FIG. 13, in the "transmission section 1301_1 of the reference signal for sector sweep for the first terminal, transmission section 1301_2 of the reference signal for sector sweep for the second terminal, transmission section 1301_3 of the reference signal for sector sweep for the third terminal, transmission section 1301_4 of the reference signal for sector sweep for the fourth terminal".

[0490] For example, as shown in FIG. 41, the terminal #1 of 902_1 transmits the sector sweep reference signal 4101_1 to the "sector sweep reference signal" transmission section for the fourth terminal of 1301_4. The terminal #2 of 902_2 transmits the sector sweep reference signal 4101_2 to the "sector sweep reference signal" transmission section for the first terminal of 1301_1. It is assumed that the terminal #3 of 902_3 transmits the sector sweep reference signal 4101_3 to the "sector sweep reference signal" transmission section for the third terminal of 1301_3.

[0491] Regarding the information transmitted by the sector sweep reference signal 4101_1 transmitted by the terminal #1 of 902_1, it is as described in Embodiment 1, Embodiment 2, etc.

[0492] Regarding the information transmitted by the sector sweep reference signal 4101_2 transmitted by the terminal #2 of 902_2, it is as described in Embodiment 1, Embodiment 2, etc.

[0493] Regarding the information transmitted by the sector sweep reference signal 4101_3 transmitted by the terminal #3 of 902_3, it is as described in Embodiment 1, Embodiment 2, etc.

[0494] For the time interval from t2 to t3 in the case where the time interval from t1 to t2 is the example shown in FIG. 41, it will be described with reference to FIGS. 42A to 42D.

[0495] Then, as shown in FIG. 42A, the base station #2 of 4001_2 transmits the "feedback signal for terminal #2 of 4201_2" as the "feedback signal for the first terminal of 3101_11" in the "feedback signal of transmission panel antenna 1 among the feedback signal groups 3002 of 3100_1".

[0496] Then, as shown in FIG. 42B, the base station #2 of 4001_2 transmits the "feedback signal for terminal #3 of 4201_3" as the "feedback signal for the fourth terminal of 3101_34" in the "feedback signal of the transmission panel antenna 2 among the feedback signal groups 3002 of 3100_2".

[0497] As shown in FIG. 42C, the base station #2 of 4001_2 transmits the "feedback signal for terminal #1 of 4201_1" as the "feedback signal for the fourth terminal of 3101_34" in the "feedback signal of the transmission panel antenna 3 among the feedback signal groups 3002 of 3100_3".

[0498] As shown in FIG. 42D, since the base station #2 of 4001_2 does not allocate to the "feedback signal of the transmission panel antenna 4 among the feedback signal groups 3002 of 3100_4", for example, the base station #2 of 4001_2 does not transmit a signal from the panel antenna 4.

[0499] At this time, it is assumed that the "feedback signal for terminal #2 of 4201_2" in FIG. 42A includes information that, for example, the terminal #2 of 902_2 can communicate (with the base station #2 of 4001_2) using the transmission panel antenna 1 of 106_1.

[0500] It is assumed that the "feedback signal for terminal #3 of 4201_3" in FIG. 42B includes information that, for example, the terminal #3 of 902_3 can communicate (with the base station #2 of 4001_2) using the transmission panel antenna 2 of 106_2.

[0501] It is assumed that the "feedback signal for terminal #1 of 4201_1" in FIG. 42C includes information that, for example, the terminal #1 of 902_1 can communicate (with the base station #2 of 4001_2) using the transmission panel antenna 3 of 106_3.

[0502] In addition, other information may be included in the feedback signal for each terminal. Examples thereof are as described in Embodiment 1, Embodiment 2, etc.

[0503] Based on the sector sweep reference signal 4101_1 in FIG. 41 transmitted by terminal #1 of 902_1, base station #2 of 4001_2 selects a transmission panel antenna (selects transmission panel antenna 3 as shown in FIG. 42C), sets the parameters of beamforming, and transmits a feedback signal 4201_1 for terminal #1.

[0504] Based on the sector sweep reference signal 4101_2 in FIG. 41 transmitted by terminal #2 of 902_2, base station #2 of 4001_2 selects a transmission panel antenna (selects transmission panel antenna 1 as shown in FIG. 42A), sets the parameters of beamforming, and transmits a feedback signal 4201_2 for terminal #2.

[0505] Based on the sector sweep reference signal 4101_3 in FIG. 41 transmitted by terminal #3 of 902_3, base station #2 of 4001_2 selects a transmission panel antenna (selects transmission panel antenna 2 as shown in FIG. 42B), sets the parameters of beamforming, and transmits a feedback signal 4201_3 for terminal #3.

[0506] Next, the time interval from t4 to t5 when the time interval from t2 to t3 is the example shown in FIGS. 42A to 42D will be described with reference to FIGS. 43A to 43D.

[0507] For example, as shown in FIG. 43A, the base station #2 of 4001_2 transmits the modulation signal (slot) addressed to terminal #2 of 4301_2 as the modulation signal (slot) addressed to the first terminal 3201_11 in the "frame of transmission panel antenna 1 among the frame group 3003 including the data symbols of 3200_1". Note that the modulation signal (slot) addressed to terminal #2 of 4301_2 contains the data addressed to terminal #2 of 902_2. Also, the modulation signal (slot) addressed to terminal #2 of 4301_2 is transmitted using transmission panel antenna 1. And the setting method of the transmission method of the modulation signal (slot) addressed to terminal #2 of 4301_2 is as described in Embodiment 1, Embodiment 2, etc. For example, as described in Embodiment 2, a plurality of modulation signals (slots) may be assigned to one terminal address.

[0508] As shown in FIG. 43B, the base station #2 of 4001_2 transmits the modulation signal (slot) addressed to terminal #3 of 4301_3 as the modulation signal (slot) addressed to the third terminal 3201_23 in the "frame of transmission panel antenna 2 among the frame group 3003 including the data symbols of 3200_2". Note that the modulation signal (slot) addressed to terminal #3 of 4301_3 contains the data addressed to terminal #3 of 902_3. Also, the modulation signal (slot) addressed to terminal #3 of 4301_3 is transmitted using transmission panel antenna 2. And the setting method of the transmission method of the modulation signal (slot) addressed to terminal #3 of 4301_3 is as described in Embodiment 1, Embodiment 2, etc. For example, as described in Embodiment 2, a plurality of modulation signals (slots) may be assigned to one terminal address.

[0509] As shown in FIG. 43C, the base station #2 of 4001_2 transmits the modulation signal (slot) addressed to terminal #1 of 4301_1 as the “modulation signal (slot) addressed to the fourth terminal 3201_34” in the “frame of transmission panel antenna 3 among the frame group 3003 including the data symbols of 3200_3”. Note that the modulation signal (slot) addressed to terminal #1 of 4301_1 contains the data addressed to terminal #1 of 902_1. Also, the modulation signal (slot) addressed to terminal #1 of 4301_1 is transmitted using the transmission panel antenna 3. The setting method of the transmission method of the modulation signal (slot) addressed to terminal #1 of 4301_1 is as described in Embodiment 1, Embodiment 2, etc. For example, as described in Embodiment 2, a plurality of modulation signals (slots) may be assigned to one terminal address.

[0510] As shown in FIG. 43D, since no modulation signal (slot) is assigned to the “frame of transmission panel antenna 4 among the frame group 3003 including the data symbols of 3200_4”, the base station #2 of 4001_2 does not transmit a modulation signal (slot).

[0511] Note that in the “modulation signal (slot) addressed to terminal #2 of 4301_2” in FIG. 43A, in addition to the data symbols, “reference signals such as DMRS, PTRS, and SRS”, pilot symbols, pilot signals, preambles, symbols including control information, etc. may be included. Note that the symbols including control information may include information on the destination terminal (ID capable of identifying the terminal), the transmission method of the modulation signal, information on the modulation method, information on the error correction coding method (code length, coding rate, etc.), information on MCS, etc.

[0512] In the "Modulation Signal (Slot) for Terminal #3 of 4301_3" in FIG. 43B, in addition to data symbols, "reference signals such as DMRS, PTRS, and SRS", pilot symbols, pilot signals, preambles, symbols including control information, etc. may be included. Note that symbols including control information may include information on the destination terminal (ID capable of identifying the terminal), the transmission method of the modulation signal, information on the modulation method, information on the error correction coding method (code length, coding rate, etc.), information on MCS, etc.

[0513] In the "Modulation Signal (Slot) for Terminal #1 of 4301_1" in FIG. 43C, in addition to data symbols, "reference signals such as DMRS, PTRS, and SRS", pilot symbols, pilot signals, preambles, symbols including control information, etc. may be included. Note that symbols including control information may include information on the destination terminal (ID capable of identifying the terminal), the transmission method of the modulation signal, information on the modulation method, information on the error correction coding method (code length, coding rate, etc.), information on MCS, etc.

[0514] As described above, the base station #2 of 4001_2 can obtain the effect of improving the data transmission efficiency in the system by allocating symbols for the destination terminal to the modulation signals transmitted for each transmission panel antenna. In addition, the terminal can obtain the effect of improving the communication capacity in the system composed of the base station and the terminal by transmitting the reference signal for sector sweep so that the number of collision occurrences is reduced.

[0515] Furthermore, the terminal #1 of 902_1, the terminal #2 of 902_2, and the terminal #3 of 902_3 in FIG. 40 can perform the following communications. In the following, the panel antennas (transmission panel antennas) of each terminal are identified using the symbol "♭mn". For example, in "♭mn", "m" indicates that it is the panel antenna of terminal #m, and "n" is the number used to identify the panel antenna. For example, ♭11 may indicate the panel antenna 1 of terminal #1, and ♭12 may indicate the panel antenna 2 of terminal #1. Also, for example, ♭21 and ♭23 may indicate the panel antenna 1 of terminal #2 and the panel antenna 3 of terminal #2, respectively. Also, for example, ♭32 and ♭34 may be the panel antenna 2 of terminal #3 and the panel antenna 4 of terminal #3, respectively. Note that the panel antennas used by each terminal shown below are merely examples, and the present disclosure is not limited thereto.

[0516] For example, it is assumed that the terminal #1 of 902_1 communicates with the base station #1 of 901_1 using the panel antenna ♭11 provided in the terminal #1 of 902_1. (At this time, as shown in FIG. 35A, the base station #1 of 901_1 uses the panel antenna 1 of the base station #1 of 901_1.)

[0517] Also, it is assumed that the terminal #1 of 902_1 communicates with the base station #2 of 4001_2 using the panel antenna ♭12 provided in the terminal #1 of 902_1. (At this time, as shown in FIG. 43C, the base station #2 of 4001_2 uses the panel antenna 3 of the base station #2 of 4001_2.)

[0518] By doing so, since the terminal #1 of 902_1 can communicate with both the base station #1 of 901_1 and the base station #2 of 4001_2, the effect of improving the data transmission efficiency can be obtained.

[0519] For example, assume that terminal #2 of 902_2 communicates with base station #1 of 901_1 using panel antenna ♭23 equipped in terminal #2 of 902_2. (At this time, as shown in FIG. 35B, base station #1 of 901_1 uses panel antenna 2 of base station #1 of 901_1.)

[0520] Also, assume that terminal #2 of 902_2 communicates with base station #2 of 4001_2 using panel antenna ♭21 equipped in terminal #2 of 902_2. (At this time, as shown in FIG. 43A, base station #2 of 4001_2 uses panel antenna 1 of base station #2 of 4001_2.)

[0521] By doing so, terminal #2 of 902_2 can communicate with both base station #1 of 901_1 and base station #2 of 4001_2, so that the effect of improving data transmission efficiency can be obtained.

[0522] For example, assume that terminal #3 of 902_3 communicates with base station #1 of 901_1 using panel antenna ♭32 equipped in terminal #3 of 902_3. (At this time, as shown in FIG. 35C, base station #1 of 901_1 uses panel antenna 3 of base station #1 of 901_1.)

[0523] Also, assume that terminal #3 of 902_3 communicates with base station #2 of 4001_2 using panel antenna ♭34 equipped in terminal #3 of 902_3. (At this time, as shown in FIG. 43B, base station #2 of 4001_2 uses panel antenna 3 of base station #2 of 4001_2.)

[0524] By doing so, terminal #3 of 902_3 can communicate with both base station #1 of 901_1 and base station #2 of 4001_2, so that the effect of improving data transmission efficiency can be obtained.

[0525] As described above, when the terminal is equipped with a plurality of panel antennas, by communicating with a plurality of base stations using the plurality of panel antennas, an effect of improving the data transmission efficiency can be obtained. Note that, as in the second embodiment, the terminal may transmit a plurality of modulation signals to one base station using a plurality of panel antennas, or the terminal may use a plurality of panel antennas to receive a plurality of modulation signals transmitted by one base station.

[0526] Next, the communication situation in an example of the communication state shown in FIG. 40 will be described. The communication situation in an example of the communication state shown in FIG. 40 may be the same as that in FIGS. 26 and 27. Hereinafter, an example of the communication situation will be described with reference to FIGS. 26 and 27.

[0527] FIG. 26 shows an example of a situation when the base station #2 of 4001_2 communicates with "the terminal #1 of 902_1, the terminal #2 of 902_2, and the terminal #3 of 902_3" in FIG. 40. FIG. 26(A) shows an example of the transmission situation of the modulation signal of the base station #2 of 4001_2, and FIG. 26(B) shows an example of the transmission situation of the modulation signals of "the terminal #1 of 902_1, the terminal #2 of 902_2, and the terminal #3 of 902_3". In FIGS. 26(A) and 26(B), it is assumed that the horizontal axis represents time. In FIG. 26, those that operate in the same manner as in FIG. 18 are given the same numbers.

[0528] First, the base station #2 of 4001_2 transmits the sector sweep reference signal 1801_1. Since this has already been described with reference to FIG. 30, the description will be omitted.

[0529] Then, terminals such as "the terminal #1 of 902_1, the terminal #2 of 902_2, and the terminal #3 of 902_3" transmit the sector sweep reference signal 1851_1. Since this has already been described with reference to FIGS. 13 and 14, the description will be omitted.

[0530] The base station #2 of 4001_2 transmits a feedback signal group 2602_1. Note that this has already been described with reference to FIGS. 31A, 31B, 31C, and 31D, so the description is omitted.

[0531] Thereafter, the base station #2 of 4001_2 transmits a "frame group 2603_1 including data symbols". Note that this has already been described with reference to FIGS. 32A, 32B, 32C, and 32D, so the description is omitted. (Therefore, the "frame 2603_1 including data symbols" is considered, for example, as a downlink frame.)

[0532] Then, terminals such as "terminal #1 of 902_1, terminal #2 of 902_2, and terminal #3 of 902_3" transmit a "frame group 2652_1 including data symbols". The configuration of this frame will be described later with reference to FIG. 44. (Therefore, the "frame group 2652_1 including data symbols" is considered, for example, as an uplink frame.)

[0533] Next, the base station #2 of 4001_2 transmits a "frame group 2603_2 including data symbols". The method of configuring the "frame group 2603_2 including data symbols" is as described with reference to FIGS. 32A, 32B, 32C, and 32D.

[0534] Then, terminals such as "terminal #1 of 902_1, terminal #2 of 902_2, and terminal #3 of 902_3" transmit a "frame group 2652_2 including data symbols". The configuration of this frame will be described later with reference to FIG. 44.

[0535] FIG. 27 shows an example of the transmission status of the modulation signal of the base station #2 of 4001_2 after FIG. 26 and the transmission status of the modulation signal of terminals such as "terminal #1 of 902_1, terminal #2 of 902_2, and terminal #3 of 902_3". In FIG. 27, those that operate in the same manner as in FIG. 18 are given the same reference numerals.

[0536] FIG. 27(A) shows an example of the transmission status of the modulation signal of base station #2 of 4001_2, which is a time continuation of the transmission status of the modulation signal of base station #2 of 4001_2 in FIG. 26(A).

[0537] FIG. 27(B) shows an example of the transmission status of the modulation signal of "Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3", which is a time continuation of the transmission status of the modulation signal of "Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3" in FIG. 26(B).

[0538] In FIGS. 27(A) and 27(B), it is assumed that the horizontal axis represents time.

[0539] After FIGS. 26(A) and (B), base station #2 of 4001_2 transmits "Frame group 2603_3 including data symbols". The method of constructing "Frame group 2603_2 including data symbols" is as described with reference to FIGS. 32A, 32B, 32C, and 32D.

[0540] Then, terminals such as "Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3" transmit "Frame group 2652_3 including data symbols". The configuration of this frame will be described later with reference to FIG. 44.

[0541] Next, base station #2 of 4001_2 transmits the sector sweep reference signal 1801_2. Since this has already been described with reference to FIG. 30, the description is omitted.

[0542] Then, terminals such as "Terminal #1 of 902_1, Terminal #2 of 902_2, Terminal #3 of 902_3" transmit the sector sweep reference signal 1851_2. Since this has already been described with reference to FIGS. 13, 14, etc., the description is omitted.

[0543] The base station #2 of 4001_2 transmits the feedback signal group 2602_2. Regarding this point, since it has already been described with reference to FIGS. 31A, 31B, 31C, and 31D, the description is omitted.

[0544] After that, the base station #2 of 4001_2 transmits the "frame group 2603_4 including data symbols". Regarding this point, since it has already been described with reference to FIGS. 32A, 32B, 32C, and 32D, the description is omitted.

[0545] Then, terminals such as "terminal #1 of 902_1, terminal #2 of 902_2, terminal #3 of 902_3" transmit the "frame group 2652_4 including data symbols". Regarding the configuration of this frame, it will be described later with reference to FIG. 44.

[0546] In this way, before the transmission of the "frame group including data symbols" of the base station #2 of 4001_2 and / or the transmission of the "frame group including data symbols" of terminals such as "terminal #1 of 902_1, terminal #2 of 902_2, terminal #3 of 902_3", the base station #2 of 4001_2 and the terminals may transmit the sector sweep reference signal. Also, after the transmission of the "frame group including data symbols" of the base station #2 of 4001_2 and / or the transmission of the "frame group including data symbols" of terminals such as "terminal #1 of 902_1, terminal #2 of 902_2, terminal #3 of 902_3", the base station #2 of 4001_2 and the terminals may transmit the sector sweep reference signal again. In this way, by selecting the transmission panel antenna to be used and setting the transmission beamforming, the base station and / or the terminal can obtain the effect of obtaining high data reception quality.

[0547] Of course, the "terminal #1 of 902_1, terminal #2 of 902_2, terminal #3 of 902_3" may communicate with the base station #1 of 901_1 in the same manner.

[0548] Also, synchronization may not be achieved (non - coherent or partial - coherent) between the communication of terminal #1 of 902_1 with two base stations (communication with base station #1 of 901_1 and communication with base station #2 of 4001_2). For example, while terminal #1 of 902_1 is transmitting a frame group (including data symbols) to base station #1 of 901_1 (see FIG. 36), it may receive a feedback signal from base station #2 of 4001_2 (see FIG. 42C). As another example, at terminal #1 of 902_1, the type of symbol transmitted by base station #1 of 901_1 received and the type of symbol transmitted by base station #2 of 4001_2 received may be different. Further, at terminal #1 of 902_1, the type of symbol destined for base station #1 of 901_1 transmitted and the type of symbol destined for base station #2 of 4001_2 transmitted may be different. Also, for terminal #2 of 902_2 and terminal #3 of 902_3, similar to terminal #1 of 902_1, synchronization may not be achieved between the communication with two base stations (communication with base station #1 of 901_1 and communication with base station #2 of 4001_2). In other words, when a terminal communicates with multiple base stations, the communication situations between the terminal and each of the multiple base stations may be independent of each other. However, the communication between the terminal and the two base stations may be synchronized (coherent or partial - coherent).

[0549] Next, a configuration example of a frame group 2652_i including data symbols transmitted by terminals such as "terminal #1 of 902_1, terminal #2 of 902_2, terminal #3 of 902_3" will be described with reference to FIG. 44. For example, let i be an integer of 1 or more, and in FIG. 44, assume that the horizontal axis represents time.

[0550] As shown in FIG. 44, assume that the "frame group 2652_i including data symbols" is composed of a first time interval, a second time interval, a third time interval, and a fourth time interval.

[0551] Then, for example, terminal #1 of 902_1 uses the fourth time interval to transmit a frame group 4401_1 (including data symbols). Also, terminal #2 of 902_2 uses the first time interval to transmit a frame group 4401_2 (including data symbols). Terminal #3 of 902_3 uses the third time interval to transmit a frame group 4401_3 (including data symbols).

[0552] Also, each terminal may transmit a modulation signal (slot) using a plurality of time intervals in FIG. 44, or each terminal may transmit a plurality of modulation signals (slots) in a certain time interval. This is as described in Embodiment 1, Embodiment 2, etc.

[0553] In this way, the frame group 2652_i including data symbols transmitted by terminals such as "terminal #1 of 902_1, terminal #2 of 902_2" performs time division, for example. Each terminal transmits a frame group, and the base station #2 of 4001_2 can suppress interference by receiving the frame groups transmitted by each terminal, so that high data reception quality can be obtained. Also, in the base station #2 of 4001_2, depending on the usage method of the panel antenna, it is possible to create a situation where even if a plurality of terminals transmit modulation signals (slots) at the same time, the interference between them is small.

[0554] Note that in the frame groups 4401_1, 4401_2, 4401_3 of FIG. 44, in addition to data symbols, for example, "reference signals such as DMRS, PTRS, SRS", pilot symbols, pilot signals, preambles, symbols including control information, etc. may be included.

[0555] In FIG. 44, the case where the frame group transmitted by the terminal uses time division has been described, but the frame group transmitted by the terminal may be frequency-divided, or space division may be performed by using a panel antenna and MU-MIMO.

[0556] FIG. 45A is a modification of FIG. 43A. In FIG. 45A, those that operate in the same manner as in FIG. 43A are given the same numbers. FIG. 45B is a modification of FIG. 43B. In FIG. 45B, those that operate in the same manner as in FIG. 43B are given the same numbers. FIG. 45C is a modification of FIG. 43C. In FIG. 45C, those that operate in the same manner as in FIG. 43C are given the same numbers. FIG. 45D is a modification of FIG. 43D. In FIG. 45D, those that operate in the same manner as in FIG. 43D are given the same numbers.

[0557] The difference between FIG. 45A and FIG. 43A is that in FIG. 43A, the modulation signal (slot) 4301_2 addressed to terminal #2 is composed of 1 slot, while in FIG. 45A, the modulation signal (slot) 4301_2 addressed to terminal #2 is composed of 3 slots. This is because in FIG. 43A, there are free slots that have not been allocated, and in FIG. 45A, the free slots are effectively utilized, so the data transmission efficiency will be improved. Note that the effective utilization of free slots is the same for FIGS. 45B and 45C. Therefore, the method of using slots is not limited to FIGS. 43A, 43B, 43C, 43D, 45A, 45B, 45C, and 45D.

[0558] Also, focusing on the second slot in each of FIGS. 45A, 45B, 45C, and 45D, the modulation signal (slot) 4301_2 addressed to terminal #2 exists in FIG. 45A, the modulation signal (slot) 4301_3 addressed to terminal #3 exists in FIG. 45B, and the modulation signal (slot) 4301_1 addressed to terminal #1 exists in FIG. 45C. For example, in this way, modulation signals (slots) with different destinations may exist for each panel antenna in a certain time interval, namely the second slot in each of FIGS. 45A, 45B, 45C, and 45D. At this time, the same frequency (the same frequency band) may be used by the four panel antennas, or the same frequency (the same frequency band) may not be used.

[0559] In addition, when the same frequency (the same frequency band) is used, it can be considered as transmission by MU-MIMO. For example, when the directivity is different for each panel antenna, even if MU-MIMO is used, an effect can be obtained in which interference with each other can be reduced. (Note that the related transmission method is also described in Embodiment 2.)

[0560] Also, when the base station #2 of 4001_2 transmits a modulation signal for each panel antenna, for example, the modulation signal transmitted by panel antenna 1 and the modulation signal transmitted by panel antenna 2 exist in the same time interval, and the frequency (frequency band) of the modulation signal transmitted by panel antenna 1 and the frequency (frequency band) of the modulation signal transmitted by panel antenna 2 may be the same or partially common.

[0561] For example, when transmitting a modulation signal from each panel antenna, the following Case 5-1, Case 5-2, and Case 5-3 can be considered.

[0562] Case 5-1: When the base station #2 of 4001_2 is equipped with a plurality of panel antennas and transmits a modulation signal from each panel antenna, in a certain time interval, a set of modulation signals with the same or partially common frequency (frequency band) may exist.

[0563] As another method, the frequency (frequency band) of the modulation signal transmitted by the base station #2 of 4001_2 using panel antenna 1 and the frequency (frequency band) of the modulation signal transmitted by panel antenna 2 may be different.

[0564] Case 5-2: When the base station #2 of 4001_2 is equipped with a plurality of panel antennas and transmits a modulation signal from each panel antenna, a set of modulation signals with different frequencies (frequency bands) may exist.

[0565] Furthermore, the frequency (frequency band) of the modulation signal transmitted by the base station #2 of 4001_2 using panel antenna 1 and the frequency (frequency band) of the modulation signal transmitted by panel antenna 2 may be the same, and these two modulation signals may be time-division multiplexed.

[0566] Case 5-3: When the base station #2 of 4001_2 is equipped with a plurality of panel antennas and transmits modulation signals from each panel antenna, there may be a set of modulation signals with the same frequency (frequency band) and time-division multiplexed.

[0567] For example, when the base station #2 of 4001_2 has the configurations shown in FIGS. 1A, 1B, and 1C, the modulation signal may be generated and transmitted from the panel antenna so that "Case 5-1 exists", and / or "Case 5-2 exists", and / or "Case 5-3 exists" according to the control signal 100. However, although the control signal 100 is configured as an output from the third processing unit, it is not limited to this configuration. For example, the control signal 100 may be an output from other internal sources or a signal from an external source.

[0568] Next, the relationship between the modulation signal transmitted by the base station #1 of 901_1 to the terminal and the modulation signal transmitted by the base station #2 of 4001_2 to the terminal in FIG. 40 will be described.

[0569] For example, in FIG. 40, the terminal #1 of 902_1 receives the modulation signal transmitted by the base station #1 of 901_1 and the modulation signal transmitted by the base station #2 of 4001_2. At this time, in a certain time interval, the frequency (frequency band) of the modulation signal transmitted by the base station #1 of 901 (to the terminal #1 of 902_1) and the frequency (frequency band) of the modulation signal transmitted by the base station #2 of 4001_2 (to the terminal #1 of 902_1) may be the same or partially common.

[0570] For example, when a terminal communicates with a plurality of base stations, the following Case 5-4, Case 5-5, and Case 5-6 can be considered.

[0571] Case 5-4: When the terminal is communicating with a plurality of base stations, in the modulation signals addressed to this terminal transmitted by the plurality of base stations, there may exist a set of modulation signals in which the frequency (frequency band) is the same or partially common in a certain time interval.

[0572] As another method, terminal #1 of 902_1 receives the modulation signal transmitted by base station #1 of 901_1 and the modulation signal transmitted by base station #2 of 4001_2. At this time, the frequency (frequency band) of the modulation signal transmitted by base station #1 of 901 (addressed to terminal #1 of 902_1) and the frequency (frequency band) of the modulation signal transmitted by base station #2 of 4001_2 (addressed to terminal #1 of 902_1) may be different.

[0573] Case 5-5: When the terminal is communicating with a plurality of base stations, in the modulation signals addressed to this terminal transmitted by the plurality of base stations, there may exist a set of modulation signals in which the frequencies (frequency bands) are different.

[0574] Furthermore, terminal #1 of 902_1 receives the modulation signal transmitted by base station #1 of 901_1 and the modulation signal transmitted by base station #2 of 4001_2. At this time, the frequency (frequency band) of the modulation signal transmitted by base station #1 of 901 (addressed to terminal #1 of 902_1) and the frequency (frequency band) of the modulation signal transmitted by base station #2 of 4001_2 (addressed to terminal #1 of 902_1) are the same, and these two modulation signals may be time-division multiplexed.

[0575] Case 5-6: When the terminal is communicating with a plurality of base stations, in the modulation signals addressed to this terminal transmitted by the plurality of base stations, there may exist a set of modulation signals in which the frequencies (frequency bands) are the same and are time-division multiplexed.

[0576] Note that, for example, the base station #1 of 901_1 has the configuration shown in FIGS. 1A, 1B, and 1C, and the base station #2 of 4001_2 has the configuration shown in FIGS. 1A, 1B, and 1C. "In the base station #1 of 901_1, a modulation signal is generated and transmitted from the panel antenna so that, according to the control signal 100, 'the case of 5-4 exists', and / or 'the case of 5-5 exists', and / or 'the case of 5-6 exists'.", "In the base station #2 of 4001_2, a modulation signal is generated and transmitted from the panel antenna so that, according to the control signal 100, 'the case of 5-4 exists', and / or 'the case of 5-5 exists', and / or 'the case of 5-6 exists'.", and appropriate switching control may be performed. However, although the control signal 100 is configured as an output from the third processing unit, it is not limited to this configuration. For example, the control signal 100 may be an output from other internal sources or a signal from an external source.

[0577] Also, the terminal #1 of 902_1 receives the modulation signal transmitted by the base station #1 of 901_1 and the modulation signal transmitted by the base station #2 of 4001_2. At this time, part or all of the data included in the modulation signal transmitted by the base station #1 of 901 (addressed to the terminal #1 of 902_1) may be included in the modulation signal transmitted by the base station #2 of 4001_2 (addressed to the terminal #1 of 902_1).

[0578] Therefore, when a terminal is communicating with a plurality of base stations, a certain piece of data may be obtained from two or more base stations. As a result, the effect of improving the reception quality of the data can be obtained.

[0579] As described in this embodiment, the terminal can obtain the effect of improving the communication capacity in a system composed of a base station and a terminal by transmitting a reference signal for sector sweep so that the number of collision occurrences decreases. Note that the configurations of the terminal and the base station are not limited to those in FIGS. 1A, 1B, and 1C. Also, the configurations of the transmission panel antenna and the reception panel antenna are not limited to those in FIGS. 3 and 4. For example, an antenna configuration capable of generating one or more or a plurality of transmission directivities and reception directivities may be used. Also, although signals, frames, etc. exist in each figure, the names are not limited to these, and the function of the signal itself to be transmitted is important.

[0580] Also, as in this embodiment, by efficiently using the panel antenna, the terminal can communicate with a plurality of base stations to obtain the effects of improving the data transmission efficiency and the data reception quality.

[0581] (Embodiment 6) In this embodiment, modifications of Embodiments 1 to 5 will be described.

[0582] FIG. 46A is a diagram showing an example of the configuration of a communication system according to Embodiment 6. As shown in FIG. 46A, it is assumed that the terminal #1 of the base stations 4601_0 and 4602_1 is communicating using the first frequency (band). Also, it is assumed that the terminal #1 of the base stations 4601_0 and 4602_1 is communicating using the second frequency (band).

[0583] For example, there is a method in which the first frequency (band) is a frequency of 52.6 GHz or higher, and the second frequency (band) is FR (Frequency Range) 1 and / or FR2. However, FR1 is a frequency of "450 MHz to 6 GHz or less", and FR2 is a frequency of "24.25 GHz to 52.6 GHz". Also, as another example, the first frequency (band) may be a frequency higher than the second frequency (band). Furthermore, the first frequency (band) may be FR2, and the second frequency (band) may be FR1.

[0584] FIG. 46B is a diagram showing an example of the configuration of a communication system different from that of FIG. 46A according to Embodiment 6. As shown in FIG. 46B, it is assumed that the base station #1 of 4601_1 communicates with the terminal #1 of 4602_1 using the first frequency (band). Also, it is assumed that the base station #2 of 4601_2 communicates with the terminal #2 of 4602_1 using the second frequency (band). Further, it is assumed that the base station #1 of 4601_1 and the base station #2 of 4601_2 communicate with each other by wire and / or wirelessly.

[0585] FIG. 47 is a diagram showing an example of the configuration of a terminal according to Embodiment 6. The communication device 4702 for the first frequency is a device that generates a modulation signal of the first frequency (band) and performs transmission. Also, the communication device 4702 for the first frequency is a device that receives a modulation signal of the first frequency (band) and performs demodulation.

[0586] Therefore, when the control signal 4722 is input to the communication device 4702 for the first frequency and the control signal 4722 contains information indicating that a modulation signal of the first frequency (band) is to be generated, the data 4701 is input, and error correction encoding, modulation (mapping based on the modulation method), processing for transmission (e.g., processing for SISO, MIMO, MISO), frequency conversion, amplification, etc. are performed to generate a modulation signal and transmit it as radio waves.

[0587] Also, based on the information in the control signal 4722, the communication device 4702 for the first frequency receives the modulation signal (radio wave) of the first frequency (band) transmitted by the communication partner, performs processing such as frequency conversion, processing for reception, and error correction decoding, and outputs the received data 4703.

[0588] Note that the specific configuration of the communication device 4702 for the first frequency may be, for example, the configuration shown in FIGS. 1A, 1B, and 1C. Examples of the operation of the communication device 4702 for the first frequency are described in Embodiments 1 to 5 and the like.

[0589] The communication device 4712 for the second frequency generates a modulated signal of the second frequency (band) and performs transmission. Also, the communication device 4712 for the second frequency receives a modulated signal of the second frequency (band) and performs demodulation.

[0590] Therefore, when the control signal 4722 is input to the communication device 4712 for the second frequency and the control signal 4722 contains information indicating that a modulated signal of the second frequency (band) is to be generated, the communication device 4712 takes the data 4711 as input, performs processes such as error correction coding, modulation (mapping based on the modulation method), processes for transmission (e.g., processes for SISO, MIMO, MISO), frequency conversion, and amplification, generates a modulated signal, and transmits it as radio waves.

[0591] Also, based on the information in the control signal 4722, the communication device 4712 for the second frequency receives the modulated signal (radio wave) of the second frequency (band) transmitted by the communication partner, performs processes such as frequency conversion, processes for reception, and error correction decoding, and outputs the received data 4713.

[0592] Note that the specific configuration of the communication device 4712 for the second frequency may be, for example, the configuration shown in FIGS. 1A, 1B, and 1C. Examples of the operation of the communication device 4712 for the second frequency are described in Embodiments 1 to 5 and the like.

[0593] The control unit 4721 takes the received data 4703 and 4713 as input, generates and outputs a control signal 4722 that contains information on the control signal for transmission of the first frequency (band), the control signal for reception of the first frequency (band), the control signal for transmission of the second frequency (band), and the control signal for reception of the second frequency (band).

[0594] FIG. 48 is a diagram showing an example of the configuration of a base station according to Embodiment 6. The communication device 4802 for the first frequency generates a modulated signal of the first frequency (band) and performs transmission. Also, the communication device 4802 for the first frequency receives a modulated signal of the first frequency (band) and performs demodulation.

[0595] Therefore, when the communication device 4802 for the first frequency takes the control signal 4822 as an input and the control signal 4822 contains information indicating that a modulation signal of the first frequency (band) is to be generated, it takes the data 4801 as an input, performs processes such as error correction coding, modulation (mapping based on the modulation method), transmission processes (e.g., processes for SISO, SIMO, MIMO, MISO), frequency conversion, and amplification, generates a modulation signal, and transmits it as a radio wave.

[0596] Also, when the communication device 4802 for the first frequency receives a modulation signal (radio wave) of the first frequency (band) transmitted by a communication partner based on the information in the control signal 4822, it performs processes such as frequency conversion, reception processes, and error correction decoding, and outputs the received data 4803.

[0597] Note that the specific configuration of the communication device 4802 for the first frequency may be, for example, the configuration shown in FIGS. 1A, 1B, and 1C. Examples of the operation of the communication device 4802 for the first frequency are described in Embodiments 1 to 5 and the like.

[0598] The communication device 4812 for the second frequency is a device that generates a modulation signal of the second frequency (band) and performs transmission. Also, the communication device 4812 for the second frequency is a device that receives a modulation signal of the second frequency (band) and performs demodulation.

[0599] Therefore, when the communication device 4812 for the second frequency takes the control signal 4822 as an input and the control signal 4822 contains information indicating that a modulation signal of the second frequency (band) is to be generated, it takes the data 4811 as an input, performs processes such as error correction coding, modulation (mapping based on the modulation method), transmission processes (e.g., processes for SISO, SIMO, MIMO, MISO), frequency conversion, and amplification, generates a modulation signal, and transmits it as a radio wave.

[0600] In addition, the communication device 4812 for the second frequency receives the modulation signal (radio wave) of the second frequency (band) transmitted by the communication partner based on the information of the control signal 4822, and performs processes such as frequency conversion, reception processing, and error correction decoding, and outputs the received data 4813.

[0601] The control unit 4821 takes the received data 4803 and 4813 as inputs, generates and outputs a control signal 4822 including information on the control signal for transmitting the first frequency (band), the control signal for receiving the first frequency (band), the control signal for transmitting the second frequency (band), and the control signal for receiving the second frequency (band).

[0602] Note that the base station #1 of 4601_1 and the base station #2 of 4601_2 shown in FIGS. 46A and 46B may have the configuration shown in FIG. 48.

[0603] FIG. 49A is a diagram showing an example of the configuration of the base station #1 of 4601_1 in FIG. 46B according to Embodiment 6. The communication device 4902 for the first frequency is a device that generates and transmits a modulation signal of the first frequency (band). In addition, the communication device 4902 for the first frequency is a device that receives and demodulates a modulation signal of the first frequency (band).

[0604] Therefore, when the communication device 4902 for the first frequency needs to generate a modulation signal of the first frequency (band) with the first control signal 4904 as an input and based on information such as the first control signal 4904, it takes the data 4901 as an input, performs processes such as error correction coding, modulation (mapping based on the modulation method), transmission processing (for example, processing for SISO, SIMO, MIMO, MISO), frequency conversion, and amplification, generates a modulation signal, and transmits it as a radio wave.

[0605] In addition, the communication device 4902 for the first frequency receives the modulation signal (radio wave) of the first frequency (band) transmitted by the communication partner based on information such as the first control signal 4904, and performs processes such as frequency conversion, reception processing, and error correction decoding, and outputs the received data 4903.

[0606] In addition, the communication device 4902 for the first frequency may output a second control signal 4905. In this case, the first control signal 4904 is a signal obtained from the base station #2 of 4601_2 via the network, and the second control signal 4905 is transmitted to the base station #2 of 4601_2 via the network.

[0607] FIG. 49B is a diagram showing an example of the configuration of the base station #2 of 4601_2 in FIG. 46B according to Embodiment 6. The communication device 4912 for the second frequency is a device that generates and transmits a modulation signal of the second frequency (band). Further, the communication device 4912 for the second frequency is a device that receives and demodulates a modulation signal of the second frequency (band).

[0608] Therefore, when the communication device 4912 for the second frequency needs to generate a modulation signal of the second frequency (band) with the third control signal 4914 as an input and based on information such as the third control signal 4914, it takes the data 4911 as an input, performs processes such as error correction coding, modulation (mapping based on the modulation method), processes for transmission (for example, processes for SISO, SIMO, MIMO, MISO), frequency conversion, and amplification, generates a modulation signal, and transmits it as a radio wave.

[0609] In addition, the communication device 4912 for the second frequency receives a modulation signal (radio wave) of the second frequency (band) transmitted by the communication partner based on information such as the third control signal 4914, performs processes such as frequency conversion, processes for reception, and error correction decoding, and outputs received data 4913.

[0610] In addition, the communication device 4912 for the second frequency may output a fourth control signal 4915. At this time, the third control signal 4914 is a signal obtained from the base station #1 of 4601_1 via the network, and the fourth control signal 4915 is transmitted to the base station #1 of 4601_1 via the network.

[0611] FIGS. 50A, 50B, and 50C are diagrams showing an example of the transmission status from time t0 to time t5.

[0612] FIG. 50A shows an example of a modulated signal of a first frequency (band) transmitted by the base station 4601_0 in FIG. 46A, or an example of a modulated signal of a first frequency (band) transmitted by the base station #1 of 4601_1 in FIG. 46B.

[0613] In FIG. 50A, those operating in the same manner as in FIG. 10 are given the same numbers.

[0614] FIG. 50B shows an example of a modulated signal of a second frequency (band) transmitted by the terminal #1 of 4602_1 in FIGS. 46A and 46B.

[0615] FIG. 50C shows an example of a modulated signal of a second frequency (band) transmitted by the base station 4601_0 in FIG. 46A, or an example of a modulated signal of a second frequency (band) transmitted by the base station #2 of 4601_2 in FIG. 46B.

[0616] An example of the operation of the communication system shown in FIG. 46A will be described.

[0617] As shown in FIG. 50A, the base station 4601_0 in FIG. 46A transmits the sector sweep reference signal 1001 in the time interval from time t0 to t1.

[0618] Note that the time interval from time t1 to t2 is the response interval of the terminal.

[0619] As shown in FIG. 50A, the base station 4601_0 in FIG. 46A transmits the feedback signal 1002 in the time interval from time t2 to t3.

[0620] FIG. 11 shows an example of the sector sweep reference signal 1001 of FIG. 50A transmitted by the base station 4601_0 in FIG. 46A. Since the operation of FIG. 11 has already been described, the description will be omitted.

[0621] FIG. 12 shows a configuration example of the "sector sweep reference signal 1101_i in the transmission panel antenna i" in FIG. 11. The operation of FIG. 12 has already been described, so the description will be omitted.

[0622] Then, as shown in FIG. 50B, the terminal #1 of 4602_1 in FIG. 46A transmits the frame T1 of 5001_1 using the second frequency (band).

[0623] At this time, the frame T1 of 5001_1 may be transmitted using the PUCCH (Physical Uplink Control Channel) as shown in FIG. 51 below.

[0624] FIG. 51 is a diagram showing an example of the PUCCH of the terminal. In FIG. 51, the horizontal axis is time and the vertical axis is frequency.

[0625] For example, the terminal #1 of 4602_1 in FIG. 46A transmits the frame T1 of 5001_1 using the "terminal #1 transmitted PUCCH" 5101_1 shown in FIG. 51.

[0626] Note that at other frequencies, there may be a "terminal #x transmitted PUCCH" 5101_x transmitted by the terminal #x.

[0627] In addition to the PUCCH, the frame T1 of 5001_1 may be transmitted using the RACH (Random Access Channel), PUSCH (Physical Uplink Shared Channel), etc., and is not limited to these.

[0628] FIG. 52 is a diagram showing an example of the configuration of the frame T1 of 5001_1 transmitted by the terminal #1 of 4602_1 in FIG. 46A.

[0629] For example, assume that the frame T1 of 5001_1 transmitted by terminal #1 of 4602_1 in Fig. 46A includes "information regarding the first frequency (band) sector sweep" 5201 and "request information for the terminal to perform / non-perform transmission in the first frequency (band)" 5202.

[0630] Assume that "information regarding the first frequency (band) sector sweep" 5201 includes information on the "transmission panel antenna of base station 4601_0 and parameter number" with good reception quality for terminal #1 of 4602_1 among the sector sweep reference signals 1001 transmitted by base station 4601_0 in Fig. 46A. This has been described in Embodiments 1 to 5 and the like.

[0631] Note that this information can be generated by obtaining the sector sweep reference signal 1001, the "ID (identification number) of the transmission panel antenna" and the "identification number (ID) of the parameter used in beamforming (directivity control)" included therein.

[0632] Assume that "request information for the terminal to perform / non-perform transmission in the first frequency" 5202 includes information on whether terminal #1 of 4602_1 in Fig. 46A performs transmission in the first frequency (band) to base station 4601_0.

[0633] Base station 4601_0 in Fig. 46A receives frame T1 of 5001_1 transmitted by terminal #1 of 4602_1. Accordingly, for example, in the time interval from time t2 to t3, base station 4601_0 transmits frame B1 of 5011_1.

[0634] Fig. 53 is a diagram showing an example of the configuration of frame B1 of 5011_1 transmitted by base station 4601_0 in Fig. 46A using the second frequency (band).

[0635] For example, assume that the frame B1 of 5011_1 transmitted by the base station 4601_0 in FIG. 46A includes the information 5301 on "the allocation of frames containing data symbols of the first frequency".

[0636] Assume that the information 5301 on "the allocation of frames containing data symbols of the first frequency" at least includes information on the slot in which the base station 4601_0 in FIG. 46A transmits data symbols addressed to the terminal #1 of 4602_1.

[0637] For example, as shown in FIG. 17, the frame 1003 containing the data symbols in FIG. 50A is composed of the modulation signal (slot) 1701_1 for the first terminal, the modulation signal (slot) 1701_2 for the second terminal, the modulation signal (slot) 1701_3 for the third terminal, and the modulation signal (slot) 1701_4 for the fourth terminal. Assume that the base station 4601_0 in FIG. 46A transmits a frame containing data symbols to the terminal #1 of 4602_1 using the modulation signal (slot) 1701_1 for the first terminal in FIG. 17.

[0638] In this case, the information 5301 on "the allocation of frames containing data symbols of the first frequency" in FIG. 53 includes the information indicating that "a frame containing data symbols is transmitted using the modulation signal (slot) 1701_1 for the first terminal".

[0639] Therefore, by obtaining the information 5301 on "the allocation of frames containing data symbols of the first frequency", the terminal #1 of 4602_1 in FIG. 46A can know the position of the frame containing the data symbols transmitted by the base station 4601_0 to the terminal #1 of 4602_1. Then, the terminal #1 of 4602_1 in FIG. 46A can receive the modulation signal of the first frequency (band) transmitted by the base station 4601_0 and obtain the data contained in the data symbols.

[0640] Note that the method for constructing a frame including the data symbol of FIG. 50A transmitted by the base station 4601_0 is not limited to FIG. 17. Regarding other methods for constructing a frame including the data symbol of FIG. 50A, for example, it is as described in Embodiments 1 to 5.

[0641] In addition, in the frame B1 of 5011_1 transmitted by the base station 4601_0 of FIG. 46A using the second frequency (band), not only information on the position of the data symbol, but also, for example, information on the error correction coding method used for generating the data symbol, information on the transmission method used for generating the data symbol, information on the modulation method used for generating the data symbol, etc. may be included.

[0642] Therefore, as shown in FIG. 50A, the base station 4601_0 of FIG. 46A transmits a "frame 1003 including a data symbol" including the data symbol addressed to the terminal #1 of 4602_1 of FIG. 46A in the time interval from time t4 to t5.

[0643] The operation when the "request information for the terminal to perform / non-perform first frequency transmission" 5202 in FIG. 52 indicates "non-performance" will be described.

[0644] When 5202 indicates "non-performance", the terminal #1 of 4602_1 in FIG. 46A will not transmit a modulation signal of the first frequency (band).

[0645] Therefore, when the terminal #1 of 4602_1 needs to transmit data to the base station 4601_0, the terminal #1 of 4602_1 will transmit, for example, a modulation signal of the second frequency (band) or a modulation signal of the third frequency (band).

[0646] Note that the third frequency (band) is a frequency (band) different from the first frequency (band), and further, the third frequency (band) is assumed to be a frequency (band) different from the second frequency (band).

[0647] The operation when "Terminal's Request Information on Whether to Perform / Not Perform First-Frequency Transmission" 5202 in Fig. 52 indicates "Perform" will be described.

[0648] When 5202 indicates "Perform", the terminal #1 of 4602_1 in Fig. 46A will transmit a modulation signal of the first frequency (band).

[0649] Therefore, the terminal #1 of 4602_1 in Fig. 46A needs to transmit a signal for sector sweep. That is, the terminal #1 of 4602_1 transmits a signal for sector sweep for determining the antenna used by terminal #1 for transmission and the beamforming parameters, and for determining the antenna used by base station 4601_0 for reception and the beamforming parameters.

[0650] Fig. 54 is a diagram showing an example when the terminal #1 of 4602_1 in Fig. 46A transmits a sector sweep signal. In Fig. 54, those operating in the same manner as in Fig. 13 are given the same numbers.

[0651] For example, in the time interval from time t1 to time t2 in Figs. 50A, 50B, and 50C, the terminal #1 of 4602_1 in Fig. 46A transmits a reference signal for sector sweep using the first frequency (band). Since the detailed method has been described in Embodiments 1 to 5 etc., it will be briefly described here.

[0652] As shown in FIG. 54, the terminal #1 of 4602_1 in FIG. 46A transmits a sector sweep reference signal 5401_1 in the "transmission section of the'sector sweep reference signal' for the first terminal" 1301_1. Then, the base station 4601_0 in FIG. 46A receives the sector sweep reference signal 5401_1 and also transmits a modulation signal to the terminal #1 of 4602_1, etc., thereby determining "the antenna and beamforming parameters used by the terminal #1 of 4602_1 for transmission, and the antenna and beamforming parameters used by the base station 4601_0 for reception". Since the details are described in Embodiments 1 to 5 etc., the description is omitted.

[0653] Note that in the above, the case where "in the time interval from time t1 to time t2 in FIGS. 50A, 50B, and 50C, the terminal #1 of 4602_1 in FIG. 46A transmits a reference signal for sector sweep using the first frequency (band)" has been described. However, the time interval during which "the terminal #1 of 4602_1 in FIG. 46A transmits a reference signal for sector sweep using the first frequency (band)" is not limited to this time interval.

[0654] For example, in the terminal response interval in another time zone, the terminal #1 of 4602_1 in FIG. 46A may transmit a reference signal for sector sweep using the first frequency (band), or may transmit a reference signal for sector sweep in the section where data symbols are transmitted.

[0655] After transmitting the reference signal for sector sweep, the terminal #1 of 4602_1 in FIG. 46A transmits a frame including data symbols to the base station 4601_0.

[0656] FIG. 55 is a diagram for explaining an example of a modulation signal of the first frequency transmitted by terminal #1. In FIG. 55, those operating in the same manner as in FIG. 20 are given the same numbers.

[0657] As shown in FIG. 55, the terminal #1 of 4602_1 in FIG. 46A will transmit frame 5501_1 containing data symbols in the first time interval in frame 1851_i containing data symbols.

[0658] The method for selecting the time interval for transmitting the frame of the terminal #1 of 4602_1 has been described in Embodiments 1 to 5 etc., so the description will be omitted.

[0659] In the frame 1003 containing the data symbols of FIG. 50A transmitted by the base station 4601_0 in the above description, the base station 4601_0 may use a transmission method of transmitting a plurality of modulation signals with a plurality of antennas.

[0660] Regarding this point, detailed descriptions have been made in Embodiments 1 to 5 etc. Also, in frame T1 of 5001_1 of FIG. 50B transmitted by the terminal #1 of 4602_1, the terminal #1 of 4602_1 may use a transmission method of transmitting a plurality of modulation signals with a plurality of antennas. And in frame B1 of 5011_1 of FIG. 50C transmitted by the base station 4601_0, the base station 4601_0 may use a transmission method of transmitting a plurality of modulation signals with a plurality of antennas.

[0661] Also, when the base station 4601_0 transmits a modulation signal using a second frequency (band), it may use a transmission method of transmitting a plurality of modulation signals with a plurality of antennas.

[0662] And when the terminal #1 of 4602_1 transmits a modulation signal using a first frequency (band), it may use a transmission method of transmitting a plurality of modulation signals with a plurality of antennas.

[0663] An operation example of the communication system shown in FIG. 46B will be described.

[0664] As shown in FIG. 50A, the base station #1 of 4601_1 in FIG. 46B transmits the sector sweep reference signal 1001 in the time interval from time t0 to t1.

[0665] Note that the time interval from time t1 to t2 is the response interval of the terminal.

[0666] As shown in FIG. 50A, the base station #1 of 4601_1 in FIG. 46B transmits a feedback signal 1002 in the time interval from time t2 to t3.

[0667] FIG. 11 shows an example of the sector sweep reference signal 1001 in FIG. 50A transmitted by the base station #1 of 4601_1 in FIG. 46B. Since the operation of FIG. 11 has already been described, the description is omitted.

[0668] FIG. 12 shows a configuration example of the "sector sweep reference signal 1101_i in the transmission panel antenna i" in FIG. 11. Since the operation of FIG. 12 has already been described, the description is omitted.

[0669] Then, as shown in FIG. 50B, the terminal #1 of 4602_1 in FIG. 46A transmits a frame T1 of 5001_1 using the second frequency (band).

[0670] At this time, the frame T1 of 5001_1 may utilize PUCCH as shown in FIG. 51.

[0671] For example, the terminal #1 of 4602_1 in FIG. 46B transmits the "terminal #1 transmission PUCCH" 5101_1 in FIG. 51 as the frame T1 of 5001_1.

[0672] Note that there may be a "terminal #x transmission PUCCH" 5101_x transmitted by the terminal #x at other frequencies.

[0673] Also, the frame T1 of 5001_1 may be transmitted using RACH, PUSCH, etc. in addition to PUCCH, and is not limited thereto.

[0674] FIG. 52 shows an example of the configuration of the frame T1 of 5001_1 transmitted by the terminal #1 of 4602_1 in FIG. 46B.

[0675] For example, assume that the frame T1 of 5001_1 transmitted by terminal #1 of 4602_1 in FIG. 46B includes "information regarding the first frequency (band) sector sweep" 5201 and "request information for the terminal to perform / non-perform transmission in the first frequency (band)" 5202.

[0676] Assume that the "information regarding the first frequency (band) sector sweep" 5201 includes information on the "transmission panel antenna of base station #1 of 4601_1 in FIG. 46B and the parameter number" with good reception quality for terminal #1 of 4602_1 among the sector sweep reference signals 1001 transmitted by base station #1 of 4601_1 in FIG. 46B. This point has been described in Embodiments 1 to 5 and the like.

[0677] Note that this information can be generated by obtaining the sector sweep reference signal 1001 and the "ID (identification number) of the transmission panel antenna" and the "identification number (ID) of the parameter used in beamforming (directivity control)" included therein.

[0678] Assume that the "request information for the terminal to perform / non-perform transmission in the first frequency" 5202 includes information on whether terminal #1 of 4602_1 in FIG. 46B performs transmission in the first frequency (band) with respect to base station #1 of 4601_1.

[0679] Base station #2 of 4601_2 in FIG. 46B receives the frame T1 of 5001_1 transmitted by terminal #1 of 4602_1. Accordingly, for example, in the time interval from time t2 to t3, base station #2 of 4601_2 transmits the frame B1 of 5011_1.

[0680] FIG. 53 shows an example of the configuration of the frame B1 of 5011_1 transmitted by base station #2 of 4601_2 in FIG. 46B using the second frequency (band).

[0681] For example, assume that the frame B1 of 5011_1 transmitted by the base station #2 of 4601_2 in FIG. 46B includes the information 5301 on "the allocation of frames containing data symbols of the first frequency".

[0682] Assume that the information 5301 on "the allocation of frames containing data symbols of the first frequency" includes at least the information on the slot in which the base station #1 of 4601_1 in FIG. 46B transmits the data symbols addressed to the terminal #1 of 4602_1.

[0683] For example, as shown in FIG. 17, the frame 1003 containing the data symbols in FIG. 50A is composed of the modulation signal (slot) 1701_1 addressed to the first terminal, the modulation signal (slot) 1701_2 addressed to the second terminal, the modulation signal (slot) 1701_3 addressed to the third terminal, and the modulation signal (slot) 1701_4 addressed to the fourth terminal. Assume that the base station #1 of 4601_1 in FIG. 46B transmits a frame containing data symbols to the terminal #1 of 4602_1 using, for example, the modulation signal (slot) 1701_1 addressed to the first terminal in FIG. 17.

[0684] In this case, the information 5301 on "the allocation of frames containing data symbols of the first frequency" in FIG. 53 includes the information indicating that "a frame containing data symbols is transmitted using the modulation signal (slot) 1701_1 addressed to the first terminal".

[0685] Therefore, by obtaining the information 5301 on "the allocation of frames containing data symbols of the first frequency", the terminal #1 of 4602_1 in FIG. 46B can know the position of the frame containing the data symbols transmitted by the base station #1 of 4601_1 to the terminal #1 of 4602_1. Then, the terminal #1 of 4602_1 in FIG. 46B can receive the modulation signal of the first frequency (band) transmitted by the base station #1 of 4601_1 and obtain the data contained in the data symbols.

[0686] Note that the method of configuring the frame including the data symbol in FIG. 50A transmitted by the base station #1 of 4601_1 is not limited to FIG. 17. Regarding other configuration methods of the frame including the data symbol in FIG. 50A, for example, it is as described in Embodiments 1 to 5.

[0687] In addition, in the frame B1 of 5011_1 transmitted by the base station #2 of 4601_2 in FIG. 46B using the second frequency (band), not only the information on the position of the data symbol but also, for example, information on the error correction coding method used for generating the data symbol, information on the transmission method used for generating the data symbol, information on the modulation method used for generating the data symbol, etc. may be included.

[0688] Therefore, as shown in FIG. 50A, the base station #1 of 4601_1 in FIG. 46B transmits the "frame 1003 including data symbols" including the data symbols addressed to the terminal #1 of 4602_1 in FIG. 46B in the time interval from time t4 to t5.

[0689] The operation when the "request information for the terminal to perform / non-perform transmission on the first frequency" 5202 in FIG. 52 indicates "non-performance" will be described.

[0690] When 5202 indicates "non-performance", the terminal #1 of 4602_1 in FIG. 46B will not transmit the modulation signal of the first frequency (band).

[0691] Therefore, when the terminal #1 of 4602_1 needs to transmit data to the base station #2 of 4601_2, the terminal #1 of 4602_1 will transmit, for example, the modulation signal of the second frequency (band).

[0692] Note that the terminal #1 of 4602_1 may transmit the modulation signal of the third frequency (band) to other base stations. At this time, the third frequency (band) is a frequency (band) different from the first frequency (band), and furthermore, the third frequency (band) is assumed to be a frequency (band) different from the second frequency (band).

[0693] The operation when the "Terminal's Request Information for Transmitting / Not Transmitting at the First Frequency" 5202 in FIG. 52 indicates "Execute" will be described.

[0694] When 5202 indicates "Execute", the terminal #1 of 4602_1 in FIG. 46B will transmit a modulation signal at the first frequency (band).

[0695] Therefore, the terminal #1 of 4602_1 in FIG. 46B needs to transmit a signal for sector sweep. That is, the terminal #1 of 4602_1 transmits a signal for sector sweep for determining the antenna used by the terminal #1 and the beamforming parameters, and for determining the antenna used by the base station #1 of 4601_1 for reception and the beamforming parameters.

[0696] FIG. 54 shows an example when the terminal #1 of 4602_1 in FIG. 46B transmits a sector sweep signal. In FIG. 54, those operating in the same manner as in FIG. 13 are given the same numbers.

[0697] For example, in the time interval from time t1 to time t2 in FIGS. 50A, 50B, and 50C, the terminal #1 of 4602_1 in FIG. 46B transmits a reference signal for sector sweep using the first frequency (band). Since the detailed method has been described in Embodiments 1 to 5 and the like, it will be briefly described here.

[0698] As shown in FIG. 54, the terminal #1 of 4602_1 in FIG. 46B transmits the sector sweep reference signal 5401_1 in the "transmission section of the'sector sweep reference signal' for the first terminal" 1301_1. Then, the base station #1 of 4601_1 in FIG. 46B receives the sector sweep reference signal 5401_1 and also transmits a modulation signal to the terminal #1 of 4602_1, etc., thereby determining "the antenna and beamforming parameters used by the terminal #1 of 4602_1 for transmission, and the antenna and beamforming parameters used by the base station #1 of 4601_1 for reception". Since the details are described in Embodiments 1 to 5 etc., the description is omitted.

[0699] Note that in the above, the case where "in the time interval from time t1 to time t2 in FIGS. 50A, 50B, and 50C, the terminal #1 of 4602_1 in FIG. 46B transmits a reference signal for sector sweep using the first frequency (band)" has been described. However, the time interval during which "the terminal #1 of 4602_1 in FIG. 46B transmits a reference signal for sector sweep using the first frequency (band)" is not limited to this time interval.

[0700] For example, in the terminal response interval in another time zone, the terminal #1 of 4602_1 in FIG. 46B may transmit a reference signal for sector sweep using the first frequency (band), or may transmit a reference signal for sector sweep in the section for transmitting data symbols.

[0701] After transmitting the reference signal for sector sweep, the terminal #1 of 4602_1 in FIG. 46B transmits a frame including data symbols to the base station #1 of 4601_1.

[0702] FIG. 55 is a diagram for explaining an example of the modulation signal of the first frequency transmitted by the terminal #1. In FIG. 55, those that operate in the same manner as in FIG. 20 are given the same numbers.

[0703] As shown in FIG. 55, the terminal #1 of 4602_1 in FIG. 46B will transmit frame 5501_1 including data symbols in the first time interval in frame 1851_i including data symbols.

[0704] Regarding the method of selecting the time interval for transmitting the frame of the terminal #1 of 4602_1, since it has been described in Embodiments 1 to 5 etc., the description will be omitted.

[0705] In the communication system of FIG. 46B, as described above, base station #1 of 4601_1 and base station #2 of 4601_2 will operate in conjunction. Therefore, base station #1 of 4601_1 and base station #2 of 4601_2 will conduct communication for exchanging information in order to implement timing control, data sharing, etc. associated with the conjunction. The communication at this time may be wired communication or wireless communication.

[0706] In addition, in frame 1003 including the data symbols of FIG. 50A transmitted by base station #1 of 4601_1 in the above description, base station #1 of 4601_1 may use a transmission method of transmitting a plurality of modulation signals with a plurality of antennas. This point has been described in detail in Embodiments 1 to 5 etc.

[0707] Also, in frame T1 of 5001_1 of FIG. 50B transmitted by the terminal #1 of 4602_1, the terminal #1 of 4602_1 may use a transmission method of transmitting a plurality of modulation signals with a plurality of antennas. And in frame B1 of 5011_1 of FIG. 50C transmitted by base station #2 of 4601_2, base station #2 of 4601_2 may use a transmission method of transmitting a plurality of modulation signals with a plurality of antennas.

[0708] Also, when the base station #2 of 4601_2 transmits a modulated signal using the second frequency (band), it may use a transmission method of transmitting a plurality of modulated signals with a plurality of antennas. And when the terminal #1 of 4602_1 transmits a modulated signal using the first frequency (band), it may use a transmission method of transmitting a plurality of modulated signals with a plurality of antennas.

[0709] A modification example of the communication system shown in FIGS. 46A and 46B will be described.

[0710] FIG. 56A is a diagram showing a modification example of the communication system of FIG. 46A. FIG. 56B is a diagram showing a modification example of the communication system of FIG. 46B. In FIGS. 56A and 56B, those that operate in the same manner as FIGS. 46A and 46B are given the same reference numerals.

[0711] In FIG. 56A, the difference from FIG. 46A is that the base station 4601_0 is communicating with the terminal #2 of 5602_1 using the first frequency (band).

[0712] Also, in FIG. 56B, the difference from FIG. 46B is that the base station #1 of 4601_1 is communicating with the terminal #2 of 5602_1 using the first frequency (band).

[0713] FIG. 57 is a diagram showing an example of a transmission situation different from FIGS. 50A, 50B, and 50C. FIG. 58 is a diagram showing an example of a transmission situation after FIG. 57.

[0714] In FIG. 57, those that operate in the same manner as FIG. 18 are given the same reference numerals and the description is omitted. Also, in FIG. 58, those that operate in the same manner as FIG. 19 are given the same reference numerals and the description is omitted. Also, in FIGS. 57 and 58, those that operate in the same manner as FIGS. 50B and 50C are given the same reference numerals and the description is omitted. Also, it is assumed that the horizontal axis shown in FIGS. 57 and 58 is time.

[0715] FIG. 57(A) shows an example of the transmission status of a modulation signal of a first frequency (band) transmitted by the base station 4601_0 in FIG. 56A, or an example of the transmission status of a modulation signal of a first frequency (band) transmitted by the base station #1 of 4601_1 in FIG. 56B.

[0716] FIG. 57(B) shows an example of the transmission status of a modulation signal of a first frequency (band) transmitted by the terminal #2 of 5602_1 in FIGS. 56A and 56B.

[0717] FIG. 57(C) shows an example of the transmission status of a modulation signal of a first frequency (band) transmitted by the terminal #1 of 4602_1 in FIGS. 56A and 56B.

[0718] FIG. 57(D) shows an example of the transmission status of a modulation signal of a second frequency (band) transmitted by the base station 4601_0 in FIG. 56A, or an example of the transmission status of a modulation signal of a second frequency (band) transmitted by the base station #2 of 4601_2 in FIG. 56B.

[0719] FIG. 58(A) shows an example of the transmission status of a modulation signal of a first frequency (band) transmitted by the base station 4601_0 in FIG. 56A, or an example of the transmission status of a modulation signal of a first frequency (band) transmitted by the base station #1 of 4601_1 in FIG. 56B.

[0720] FIG. 58(B) shows an example of the transmission status of a modulation signal of a first frequency (band) transmitted by the terminal #2 of 5602_1 in FIGS. 56A and 56B.

[0721] FIG. 58(C) shows an example of the transmission status of a modulation signal of a first frequency (band) transmitted by the terminal #1 of 4602_1 in FIGS. 56A and 56B.

[0722] FIG. 58(D) shows an example of the transmission status of a modulation signal of a second frequency (band) transmitted by the base station 4601_0 in FIG. 56A, or an example of the transmission status of a modulation signal of a second frequency (band) transmitted by the base station #2 of 4601_2 in FIG. 56B.

[0723] FIG. 58(A) shows the time continuation of the transmission status of the modulation signal of the first frequency (band) transmitted by the base station 4601_0 of FIG. 56A shown in FIG. 57(A), or the time continuation of the transmission status of the modulation signal of the first frequency (band) transmitted by the base station #1 of 4601_1 in FIG. 56B.

[0724] FIG. 58(B) shows the time continuation of the transmission status of the modulation signal of the first frequency (band) transmitted by the terminal #2 of 5602_1 in FIGS. 56A and 56B of FIG. 57(B).

[0725] An operation example of the communication system shown in FIG. 56A will be described.

[0726] As shown in FIG. 57(A), the base station 4601_0 in FIG. 56A transmits the sector sweep reference signal 1801_1. The terminal #1 of 4602_1 and the terminal #2 of 5602_1 will receive the sector sweep reference signal 1801_1.

[0727] Note that the specific operation of transmitting the sector sweep reference signal 1801_1 by the base station 4601_0 has already been described in Embodiments 1 to 5 and the like, so the description is omitted.

[0728] Also, the specific operation of receiving the sector sweep reference signal 1801_1 by the terminal #1 of 4602_1 and the terminal #2 of 5602_1 has already been described in Embodiments 1 to 5 and the like, so the description is omitted.

[0729] As shown in FIG. 57(B), the terminal #2 of 5602_1 transmits the sector sweep reference signal 1851_1.

[0730] Note that the specific operation regarding the transmission of the sector sweep reference signal 1851_1 transmitted by the terminal #2 of 5602_1 has already been described in Embodiments 1 to 5 and the like, so the description is omitted.

[0731] Thereafter, the base station 4601_0 in FIG. 56A will transmit frame 1803_1 including the data symbol in FIG. 57(A) and frame 1803_3 including the data symbol in FIG. 58(A) using the first frequency (band). The frames 1803_1 including the data symbol and the frames 1803_3 including the data symbol will include symbols addressed to terminal #2 of 5602_1.

[0732] Also, the base station 4601_0 in FIG. 56A will transmit the sector sweep reference signal 1801_1, the feedback signal 1802_1, and frame 1803_2 including the data symbol using the first frequency (band).

[0733] Then, terminal #2 of 5602_1 in FIG. 56A will transmit frames 1852_1, 1852_2 including the data symbol in FIG. 57(B) and frame 1852_3 including the data symbol in FIG. 58(B) to the base station 4601_0 in FIG. 56A using the first frequency (band).

[0734] Thereafter, terminal #2 of 5602_1 in FIG. 56A will transmit the sector sweep reference signal 1851_2 and frame 1852_4 including the data symbol as shown in FIG. 58(B).

[0735] The operations in FIGS. 57(A), 58(A), 57(B), and 58(B) described above are as explained in Embodiment 1 to Embodiment 5 and the like.

[0736] Also, similar to FIG. 50B, as shown in FIG. 57(C), terminal #1 of 4602_1 in FIG. 56A will transmit frame T1 of 5001_1 using the second frequency (band).

[0737] Note that since the data included in frame T1 of 5001_1 has already been described, the description wi...

Claims

1. A control circuit that selects one first beam from a plurality of beams used by a first TRP (transceiver point) and selects one second beam from a plurality of beams used by a second TRP; A transmitter that transmits information regarding the first beam and information regarding the second beam to a third TRP using one piece of control information; When communication with the first TRP is not performed, the information regarding the first beam includes information indicating that communication with the first TRP is not performed. When communication with the second TRP is not performed, the information regarding the second beam includes information indicating that communication with the second TRP is not performed. A terminal.

2. The first beam is determined based on a reference signal transmitted by the first TRP. The second beam is determined based on a reference signal transmitted by the second TRP. The terminal according to claim 1.

3. The control information is transmitted using DFT-S OFDM (Discrete Fourier Transform - Spread Orthogonal Frequency Division Multiplexing). The terminal according to claim 1.

4. The transmitter transmits a signal to the first TRP and the second TRP in a time interval during which the control information is transmitted to the third TRP. The terminal according to claim 1.

5. A terminal selects one first beam from a plurality of beams used by a first TRP (transceiver point) and selects one second beam from a plurality of beams used by a second TRP; transmits information regarding the first beam and information regarding the second beam to a third TRP using one piece of control information; When communication with the first TRP is not performed, the information regarding the first beam includes information indicating that communication with the first TRP is not performed. When communication with the second TRP is not performed, the information regarding the second beam includes information indicating that communication with the second TRP is not performed. Communication method. Claim 6 The first beam is determined based on a reference signal transmitted by the first TRP. The second beam is determined based on a reference signal transmitted by the second TRP. The communication method according to claim 5. Claim 7 The control information is transmitted using DFT-S OFDM (Discrete Fourier Transform - Spread Orthogonal Frequency Division Multiplexing). The communication method according to claim 5. Claim 8 Transmit signals to the first TRP and the second TRP in a time interval for transmitting the control information to the third TRP. The communication method according to claim 5. Claim 9 Implemented in a terminal Control a process of selecting one first beam from a plurality of beams used by a first TRP (transmission and reception point) and selecting one second beam from a plurality of beams used by a second TRP, and a process of transmitting information regarding the first beam and information regarding the second beam to a third TRP using one control information. When communication with the first TRP is not performed, the information regarding the first beam includes information indicating that communication with the first TRP is not performed. When communication with the second TRP is not performed, the information regarding the second beam includes information indicating that communication with the second TRP is not performed. Integrated circuit.

Images