Wireless base station and terminal device

Abstract

The present disclosure relates to a wireless base station and a terminal device that can shorten the time required for a plurality of wireless base stations to collect probe information and suppress a decrease in following accuracy. When a wireless base station serving as a master station performs channel measurement with a terminal device, the wireless base station instructs other wireless base stations to perform channel measurement by transmitting a probe trigger frame including a transmission timing or a transmission stream of a channel measurement frame only once. Thus, a channel measurement frame for a wireless base station including the wireless base station can be transmitted at the same timing or different timings. The present disclosure can be applied to a communication system using a wireless LAN.

Description

[0001] This application is a divisional application of the patent application with international application number PCT / JP2019 / 051401 and national application number 201980087642.0, entitled “Wireless Base Station and Terminal Equipment”, filed on December 27, 2019. Technical Field

[0002] The present disclosure relates to a wireless base station and a terminal device, and more particularly to a wireless base station and a terminal device that can shorten the time required for a plurality of wireless base stations to collect probe information and suppress a decrease in following accuracy. Background Art

[0003] In recent years, multiple wireless base stations have been installed even in homes.

[0004] In addition, in the next generation IEEE 802.11 standard, it is assumed that transmission is performed through cooperation of wireless base stations, for example, simultaneous transmission from multiple wireless base stations to one terminal device. In this case, each wireless base station needs to acquire information related to the channel of the terminal device through detection.

[0005] As is well known, in the case where each wireless base station independently performs detection through an explicit feedback method, since a frame for detection such as a Null Data Packet Announcement (NDP-A) frame or a Null Data Packet (NDP) frame needs to be sent each time, the detection takes time and the degree of traceability of channel fluctuations becomes poor.

[0006] Therefore, a method has been proposed (non-patent document 1) in which wireless base stations that are slave stations of a wireless base station that is a master station simultaneously send NDP-A frames or NDP frames through a trigger from the wireless base station that is a master station to shorten the detection sequence in multiple wireless base stations.

[0007] Reference List

[0008] Non-patent literature

[0009] Non-patent document 1: IEEE 802.11-18 / 1439r0 Summary of the invention

[0010] Problems to be solved by the present invention

[0011] However, in the technology of Non-Patent Document 1, only the case where wireless base stations cooperate with each other to simultaneously transmit frames for sounding is assumed, and it is not assumed that frames for sounding are independently transmitted by each wireless base station.

[0012] Therefore, in the case where each wireless base station independently transmits a frame for sounding, sounding cannot be achieved.

[0013] The present disclosure has been made in view of such circumstances, and in particular, the present disclosure shortens the time required to collect detection information of a plurality of wireless base stations and suppresses a decrease in following accuracy.

[0014] Solution to the problem

[0015] A wireless base station of a first aspect of the present disclosure is a wireless base station including a control unit that, when performing channel measurement with a terminal device, performs control to transmit a start frame instructing other wireless base stations to perform channel measurement.

[0016] In the first aspect of the present disclosure, when performing channel measurement with a terminal device, control is performed to transmit a start frame that instructs other wireless base stations to perform channel measurement.

[0017] A wireless base station according to a second aspect of the present disclosure is a wireless base station, comprising a control unit, which performs control to receive a start frame sent from other wireless base stations and instructs execution of channel measurement with a terminal device, and also performs control to send a channel measurement frame based on at least one of timing information or spatial information for sending a channel measurement frame, wherein the channel measurement frame is a frame for channel measurement described in the start frame.

[0018] In a second aspect of the present disclosure, control is performed to receive a start frame sent from other wireless base stations and indicating the execution of channel measurement with a terminal device, and control is also performed to send a channel measurement frame based on at least one of the timing information or spatial information used to send the channel measurement frame, wherein the channel measurement frame is a frame for channel measurement described in the start frame.

[0019] The terminal device of the third aspect of the present disclosure is a terminal device, including a control unit, which performs control to receive a start frame, the start frame including information sent from a wireless base station and indicating that channel measurement is performed between the terminal device and the wireless base station and also indicating a sending method when a channel measurement result as a result of the channel measurement is sent to the wireless base station as sending method information, performs control to receive a frame for channel measurement sent from the wireless base station based on the start frame to perform channel measurement, and performs control to send the channel measurement result to the wireless base station based on the sending method information.

[0020] In a third aspect of the present disclosure, control is performed to receive a start frame, the start frame including information as transmission method information that is sent from a wireless base station and indicates that channel measurement is performed between the terminal device and the wireless base station and also indicates a transmission method when a channel measurement result as a result of the channel measurement is sent to the wireless base station, control is performed to receive a frame for channel measurement sent from the wireless base station based on the start frame to perform channel measurement, and control is performed to send the channel measurement result to the wireless base station based on the transmission method information. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a timing diagram for explaining standardized detection.

[0022] Figure 2 is a timing diagram for illustrating the proposed detection.

[0023] Figure 3 It is a timing chart for explaining the outline of the detection of the present disclosure.

[0024] Figure 4 It is a timing chart for explaining the outline of the detection of the present disclosure.

[0025] Figure 5 is a diagram for explaining a configuration example of a communication system of the present disclosure.

[0026] Figure 6 It is used to illustrate Figure 5 A diagram of an example configuration of a wireless base station.

[0027] Figure 7 It is used to illustrate Figure 5 A diagram of an example configuration of a terminal device.

[0028] Figure 8 is a diagram for explaining a configuration example of a detection trigger frame.

[0029] Fig. 9 is a diagram for explaining the mapping matrix.

[0030] Fig.10 It is a diagram for explaining a configuration example of NDP-A.

[0031] Fig.11 1 is a flowchart for explaining the communication process performed by the wireless base station as the master station in the first embodiment.

[0032] Fig.12 1 is a flowchart for explaining communication processing performed by the wireless base station as a slave station in the first embodiment.

[0033] Fig.131 is a flowchart for explaining the communication processing performed by the terminal device in the first embodiment.

[0034] Fig.14 It is a diagram for explaining an application example in the first embodiment.

[0035] Fig.15 is a timing chart for explaining detection in the second embodiment.

[0036] Fig.16 is a timing chart for explaining detection in the second embodiment.

[0037] Fig.17 is a diagram for explaining a configuration example of a BFRP trigger frame.

[0038] Fig.18 1 is a flowchart for explaining the communication process performed by the wireless base station as the master station in the second embodiment.

[0039] Fig.19 1 is a flowchart for explaining communication processing performed by a wireless base station as a slave station in the second embodiment.

[0040] Fig. 20 1 is a flowchart for explaining the communication processing performed by the terminal device in the first embodiment.

[0041] Fig.21 is a diagram for explaining a configuration example of a general-purpose personal computer. DETAILED DESCRIPTION

[0042] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Note that in this specification and the drawings, the same reference numerals are given to constituent elements having substantially the same functional configuration, and redundant descriptions are omitted.

[0043] Hereinafter, embodiments for carrying out the present technology will be described. The description will be given in the following order.

[0044] 1. Overview of the present disclosure

[0045] 2. First embodiment

[0046] 3. Application Examples of the First Embodiment

[0047] 4. Second Embodiment

[0048] 5. Examples executed by software

[0049] <<1. Overview of the present disclosure>>

[0050] <Standardized detection>

[0051] The present disclosure is a communication system which shortens the time required to collect probe information of a plurality of base stations in a wireless LAN (Wireless Local Area Network, Wave LAN) standardized by IEEE 802.11 and suppresses a decrease in following accuracy.

[0052] Before describing the communication system of the present disclosure, an outline of the present disclosure will be described.

[0053] For example, consider probing in a communication system standardized by IEEE 802.11 and including wireless base stations (access points) AP1, AP2 and a terminal device STA1.

[0054] In this case, in the case of explicit feedback method detection described in the IEEE 802.11ax standard, the wireless base stations AP1, AP2 transmit a Null Data Packet (NDP) frame to the terminal device STA1 for checking the reception state in the terminal device STA1, and the terminal device STA1 receives the NDP frame.

[0055] Then, the terminal device STA1 measures a channel quality indicator (CQI) which is a reception status of the NDP, generates a CQI feedback frame based on the measurement result, and returns the CQI feedback frame to the wireless base stations AP1 and AP2.

[0056] The wireless base stations AP1 and AP2 derive the optimal transfer function of the transmission path based on the CQI feedback frame returned from the terminal device STA1, and implement the optimal beamforming of the terminal device STA1.

[0057] More specifically, if Figure 1 As shown in the timing diagram, at time t1, the wireless base station AP1 as the master station sends an NDP announcement (NDP-A) frame to the terminal device STA1. The NDP-A frame is information that specifies the frame format of the NDP frame.

[0058] By receiving this NDP-A frame, the terminal device STA1 recognizes the frame format of the NDP frame to be transmitted next from the wireless base station AP1.

[0059] At time t2, the wireless base station AP1 transmits an NDP frame.

[0060] Here, the terminal device STA1 receives the NDP frame transmitted from the wireless base station AP1 and measures the CQI.

[0061] Then, at time t3, the terminal device STA1 generates a CQI feedback frame for feeding back the CQI as the measurement result, and transmits the CQI feedback frame to the wireless base station AP1.

[0062] The wireless base station AP1 receives the transmitted CQI feedback frame, obtains the optimal transfer function of the transmission path to the terminal device STA1, and implements the optimal beamforming of the terminal device STA1.

[0063] Similarly, at time t4, the wireless base station AP2, which is a slave station of the wireless base station AP1, transmits an NDP announcement (NDP-A) frame, which is information specifying the frame format of the NDP, to the terminal device STA1.

[0064] By receiving the NDP-A frame, the terminal device STA1 recognizes the frame format of the NDP frame to be transmitted next from the wireless base station AP2.

[0065] At time t5, the wireless base station AP2 transmits an NDP frame.

[0066] Here, the terminal device STA1 receives the NDP frame transmitted from the wireless base station AP2 and measures the CQI.

[0067] Then, at time t6, the terminal device STA1 generates a CQI feedback frame for feeding back the CQI as the measurement result, and transmits the CQI feedback frame to the wireless base station AP2.

[0068] The wireless base station AP2 receives the transmitted CQI feedback frame, obtains the optimal transfer function of the transmission path to the terminal device STA1, and implements the optimal beamforming to the terminal device STA1.

[0069] The detection is achieved through the above series of processing.

[0070] <Proposed Probe>

[0071] However, the following sequence is repeated for the number of wireless base stations AP1 , AP2 : each of the wireless base stations AP1 , AP2 independently transmits an NDP-A frame and an NDP frame and receives CQI feedback from the terminal device STA1 .

[0072] Therefore, all the wireless base stations AP1, AP2 take time to collect CQIs, and there is a risk that traceability will deteriorate.

[0073] Therefore, the wireless base station AP1 as the master station transmits a slave trigger frame for synchronously transmitting the NDP-A frame and the NDP frame to the wireless base station AP2 as the slave station.

[0074] Then, a technique has been proposed in which the wireless base station AP2 can transmit the NDP-A frame and the NDP frame in synchronization with the wireless base station AP1 as a master station based on a slave trigger frame.

[0075] That is, more specifically, Figure 2As shown in the timing chart of , at time t11, the wireless base station AP1 as the master station transmits a slave trigger frame instructing the transmission of an NDP-A frame to the wireless base station AP2 as the slave station.

[0076] Therefore, the wireless base station AP2 serving as a slave station recognizes the transmission instruction of the NDP-A frame.

[0077] In addition, in the slave trigger frame, a transmission flow when NDP-A is transmitted in the wireless base station AP2 as a slave station and the like are also specified.

[0078] The wireless base station AP2 transmits the NDP-A frame in the designated transmission flow.

[0079] The transmission stream specified when transmitting the NDP-A frame included in the slave trigger frame is a transmission stream different from the transmission streams of other wireless base stations, and the terminal device STA1 can receive the NDP-A frame from the wireless base stations AP1, AP2, thereby distinguishing these frames from each other.

[0080] Then, at time t12, the wireless base stations AP1 and AP2 synchronously transmit NDP-A frames at the same time.

[0081] At this time, the terminal device STA1 receives the NDP-A frame transmitted from each of the wireless base stations AP1 , AP2 , and recognizes the format of the NDP frame from the wireless base stations AP1 , AP2 .

[0082] At time t13, the wireless base station AP1 as the master station transmits a slave trigger frame instructing the transmission of an NDP frame to the wireless base station AP2 as the slave station.

[0083] Therefore, the wireless base station AP2 serving as a slave station recognizes the instruction to transmit the NDP frame.

[0084] In addition, in the slave trigger frame, a transmission flow when the NDP frame is transmitted in the wireless base station AP2 as a slave station and the like are also specified.

[0085] The wireless base station AP2 transmits the NDP frame in the designated transmission flow.

[0086] The transmission stream specified when transmitting the NDP frame included in the slave trigger frame is a transmission stream different from the transmission streams of other wireless base stations, and the terminal device STA1 can receive the NDP frames from the wireless base stations AP1, AP2, thereby distinguishing these frames from each other.

[0087] Then, at time t14, the wireless base stations AP1 and AP2 synchronously transmit NDP frames at the same time.

[0088] At this time, the terminal device STA1 receives the NDP frame transmitted from the wireless base stations AP1, AP2, receives the NDP frame from each of the wireless base stations AP1, AP2, and measures each CQI.

[0089] Then, at time t15, the terminal device STA1 generates a CQI feedback frame including two CQIs as measurement results of corresponding NDP frames from the wireless base stations AP1, AP2, and transmits the CQI feedback frame to the wireless base stations AP1, AP2.

[0090] The wireless base stations AP1 and AP2 receive each transmitted CQI feedback frame, derive the best transfer function of the transmission path to the terminal device STA1 based on each CQI, and implement the best beamforming to the terminal device STA1.

[0091] Through the above processing, the NDP-A frame and the NDP frame from the wireless base stations AP1 and AP2 can be transmitted only once.

[0092] In addition, the terminal device STA1 only needs to send a CQI feedback frame including the CQIs of both the wireless base stations AP1 and AP2 once.

[0093] In either case, the collection of CQIs in the wireless base stations AP1 and AP2 can be performed quickly.

[0094] <Detection of the Present Disclosure>

[0095] However, in reference Figure 2 In the proposed detection described in the timing diagram in , it is necessary to send a slave trigger frame at a timing immediately before each time an NDP-A frame or an NDP frame is sent, and the time required to collect CQI is required accordingly.

[0096] In addition, the slave wireless base station AP2 must transmit the NDP-A frame and the NDP frame at a timing when a predetermined time has passed after receiving the slave trigger frame, so the NDP-A frame and the NDP frame are synchronously transmitted from a plurality of wireless base stations.

[0097] Therefore, when multiple wireless base stations are configured to be able to send NDP-A frames and NDP frames at coordinated and synchronized timing, detection can be achieved. However, when multiple wireless base stations are each configured to be able to send NDP-A frames and NDP frames independently, detection cannot be achieved.

[0098] Therefore, in the present disclosure, a probe trigger frame for notifying the start of synchronization probe is defined.

[0099] In addition to the information corresponding to the NDP-A frame, the detection trigger frame also includes a description of information related to at least one of the transmission timing or transmission parameters of the NDP frame relative to the wireless base station AP2 as a slave station and the terminal device STA1, and a transmission method when a CQI feedback frame is sent from the terminal device STA1.

[0100] Therefore, based on the transmission timing of the NDP frame described in the sounding trigger frame, a plurality of wireless base stations can transmit the NDP frame at the same timing or at different timings.

[0101] More specifically, in the case where a plurality of wireless base stations are configured to be able to transmit NDP-A frames and NDP frames at coordinated and synchronized timing, processing such as Figure 3 As shown in the timing diagram.

[0102] That is, at time t21, the wireless base station AP1 transmits a probe trigger frame describing the transmission timing and transmission parameters of the NDP frame to the wireless base station AP2 and the terminal device STA1.

[0103] Here, the wireless base station AP2 and the terminal device STA1 receive the detection trigger frame and recognize the transmission timing and transmission parameters of the NDP frame.

[0104] That is, the wireless base station AP2 and the terminal device STA1 recognize the transmission timing and transmission flow of the NDP frame of the wireless base stations AP1 and AP2 based on the detection trigger frame, and recognize the transmission method of the CQI feedback frame transmitted by the terminal device STA1.

[0105] At time t22, the wireless base stations AP1, AP2 transmit NDP frames in their respective transmission streams at the transmission timing specified by the probe trigger frame.

[0106] Here, the terminal device STA1 receives the NDP frame transmitted in the corresponding transmission streams of the wireless base stations AP1, AP2 at the transmission timing specified by the probe trigger frame, and measures each CQI.

[0107] At time t23, the terminal device STA1 generates a CQI feedback frame including the CQI as the measurement result, and transmits the CQI feedback frame by the transmission method specified by the sounding trigger frame.

[0108] Here, the wireless base stations AP1 and AP2 receive the transmitted CQI feedback frames, derive the best transfer function of the transmission path to the terminal device STA1 based on each CQI, and implement the best beamforming to the terminal device STA1.

[0109] In addition, in the case where the plurality of wireless base stations are configured to be unable to transmit NDP-A frames or NDP frames at coordinated and synchronized timing (i.e., the plurality of wireless base stations are each configured to transmit NDP-A frames or NDP frames at different timings), processing such as Figure 4 As shown in the timing diagram.

[0110] That is, at time t31, the wireless base station AP1 transmits a probe trigger frame describing the transmission time and transmission parameters of the NDP frame to the wireless base station AP2 and the terminal device STA1.

[0111] Here, the wireless base station AP2 and the terminal device STA1 receive the probe trigger frame, and recognize the transmission timing and transmission parameters (transmission flow, etc.) of the NDP frame.

[0112] That is, the wireless base station AP2 and the terminal device STA1 recognize the transmission timing and transmission flow of the NDP frame of each of the wireless base stations AP1, AP2, and recognize the transmission method of the CQI feedback frame transmitted by the terminal device STA1.

[0113] At time t32, the wireless base station AP1 transmits the NDP in the designated transmission stream at the transmission timing designated by the probe trigger frame.

[0114] Here, the terminal device STA1 receives the NDP transmitted in the designated transmission stream from the wireless base station AP1 at the transmission timing designated by the probe trigger frame, and measures the CQI of the wireless base station AP1.

[0115] At time t33, the wireless base station AP2 transmits the NDP in the designated transmission stream at the transmission timing designated by the probe trigger frame.

[0116] Here, the terminal device STA1 receives the NDP transmitted in the designated transmission stream from the wireless base station AP2 at the transmission timing designated by the probe trigger frame, and measures the CQI of the wireless base station AP2.

[0117] At time t34 , the terminal device STA1 generates a CQI feedback frame including CQI as a measurement result of each of the wireless base stations AP1 , AP2 , and transmits the CQI feedback frame in the transmission stream specified by the sounding trigger frame.

[0118] Here, the wireless base stations AP1 and AP2 receive the transmitted CQI feedback frames, derive the best transfer function of the transmission path to the terminal device STA1 based on each CQI, and implement the best beamforming to the terminal device STA1.

[0119] In any case, through the above processing, the sending timing and sending parameters of the NDP frame can be sent to the wireless base station and terminal device as the slave station in one detection trigger frame without sending a trigger frame every time the NDP frame is sent, so that CQI can be quickly collected in the terminal device STA1.

[0120] In addition, since the sending timing of the NDP frame of each wireless base station can be set individually by the detection trigger frame, detection can be achieved even when multiple wireless base stations are configured not to send NDP-A frames or NDP frames at the same coordinated and synchronized timing.

[0121] <<2. First embodiment>>

[0122] Next, we will refer to Figure 5 A configuration example of the first embodiment of the communication system of the present disclosure is described.

[0123] The communication system of the present disclosure includes wireless base stations 11 - 1 , 11 - 2 and terminal devices 12 - 1 to 12 - 4 .

[0124] Note that unless it is necessary to distinguish the wireless base stations 11-1, 11-2 and the terminal devices 12-1 to 12-4, they are simply referred to as the wireless base station 11 and the terminal device 12. Figure 5 The configuration in the communication system is an example, and the number of wireless base stations 11 may be other than two, and similarly, the number of terminal devices 12 may be other than four.

[0125] The wireless base stations 11 - 1 , 11 - 2 function as so-called access points, and transmit NDP frames as probe frames to the terminal devices 12 - 1 to 12 - 4 .

[0126] Then, the wireless base stations 11-1, 11-2 receive the CQI feedback frames for the NDP frames from the terminal devices 12-1 to 12-4, obtain the transfer function of each transmission path, and implement optimal beamforming.

[0127] Terminal devices 12-1 to 12-4 are, for example, smartphones, etc., and receive NDP frames as sounding frames from wireless base stations 11-1, 11-2, measure CQI, generate CQI feedback frames including CQI as measurement results, and return the CQI feedback frames.

[0128] The terminal devices 12 - 1 , 12 - 2 communicate via the beamformed transmission paths implemented by the wireless base stations 11 - 1 , 11 - 2 according to the CQI feedback frames.

[0129] <Configuration Example of Wireless Base Station>

[0130] Next, we will refer to Figure 6 The block diagram in describes a configuration example of the wireless base station 11.

[0131] The wireless base station 11 includes a control unit 31 , a power supply unit 32 , a communication unit 33 , and antennas 34 - 1 to 34 - n .

[0132] The control unit 31 includes a processor and a memory, and controls the overall operation of the wireless base station 11 .

[0133] More specifically, the control unit 31 generates a probe trigger frame as described later, and controls the communication unit 33 to transmit the probe trigger frame to another wireless base station 11 and the terminal device 12 as slave stations.

[0134] In addition, the control unit 31 controls the communication unit 33 to send the NDP frame to the terminal device 12.

[0135] Furthermore, the control unit 31 controls the communication unit 33 to receive a CQI feedback frame transmitted from the terminal device 12 and including a measurement result of the CQI measured when the NDP frame is received, thereby achieving sounding.

[0136] Then, the control unit 31 controls the communication unit 33 based on the CQI feedback as the sounding result to perform beamforming based on the optimal transfer function and realize optimal communication with the terminal device 12 .

[0137] Note that the control unit 31 may perform at least a part of the operations on behalf of the wireless control unit 51 of the communication unit 33 .

[0138] In addition, the power supply unit 32 includes a battery power supply or a fixed power supply, and supplies power to the entire wireless base station 11 .

[0139] The communication unit 33 is controlled by the control unit 31 and performs various communication processes.

[0140] More specifically, the communication unit 33 includes a wireless control unit 51 , a data processing unit 52 , a modulation and demodulation unit 53 , a spatial signal processing unit 54 , wireless interface units 55 - 1 to 55 - n , amplifier units 56 - 1 to 56 - n , and a channel estimation unit 57 .

[0141] The wireless interface units 55-1 to 55-n, the amplifier units 56-1 to 56-n, the channel estimation unit 57, and the antennas 34-1 to 34-n form one group, and it is sufficient to include one or more groups as components.

[0142] In addition, the functions of the amplifier units 56 - 1 to 56 - n may be included in the wireless interface units 55 - 1 to 55 - n.

[0143] The data processing unit 52 generates packets for wireless transmission based on the data when data is input from an upper layer, performs processing such as adding a header or an error detection code of a media access control (MAC), and outputs the processed data to the modulation and demodulation unit 53.

[0144] In addition, conversely, when receiving an input from the modulation and demodulation unit 53, the data processing unit 52 performs processing such as analyzing a MAC header, detecting a packet error, or reordering processing, and outputs the processed data to an upper layer of its own protocol.

[0145] The wireless control unit 51 transmits and receives information to and from each unit.

[0146] In addition, the wireless control unit 51 performs parameter setting in the modulation and demodulation unit 53, parameter setting in the spatial signal processing unit 54, packet scheduling in the data processing unit 52, parameter setting in the wireless interface units 55-1 to 55-n and the amplifier units 56-1 to 56-n, and transmission power control.

[0147] At the time of transmission, the modulation and demodulation unit 53 performs encoding, interleaving, and modulation on the input data from the data processing unit 52 based on the encoding method and modulation method set by the wireless control unit 51 to generate a data symbol stream, and outputs the data symbol stream to the spatial signal processing unit 54.

[0148] In addition, the modulation and demodulation unit 53 performs reverse processing on the input from the spatial signal processing unit 54 upon reception, and outputs the data to the data processing unit 52 or the wireless control unit 51 .

[0149] At the time of transmission, the spatial signal processing unit 54 performs signal processing for spatial separation on the input from the modulation and demodulation unit 53 as necessary, and outputs the obtained one or more transmission symbol streams to each of the wireless interface units 55-1 to 55-n.

[0150] In addition, upon reception, the spatial signal processing unit 54 performs signal processing on a reception symbol stream input from each of the wireless interface units 55 - 1 to 55 - n , spatially decomposes the stream as necessary, and outputs the result to the modulation and demodulation unit 53 .

[0151] The channel estimation unit 57 calculates complex channel gain information of the propagation path based on the preamble part and the training signal part of the input signal from each of the wireless interface units 55-1 to 55-n.

[0152] The calculated composite channel gain information is used for demodulation processing in the modulation and demodulation unit 53 and spatial processing in the spatial signal processing unit 54 via the wireless control unit 51 .

[0153] The wireless interface units 55-1 to 55-n convert the input from the spatial signal processing unit 54 into an analog signal when transmitting, perform filtering, up-conversion to a carrier frequency and phase control, and output the result to the antennas 34-1 to 34-n or amplifier units 56-1 to 56-n.

[0154] In addition, the wireless interface units 55 - 1 to 55 - n perform reverse processing on input from the antenna or amplifier unit at the time of reception, and output data to the spatial signal processing unit 54 and the channel estimation unit 57 .

[0155] At the time of transmission, the amplifier units 56 - 1 to 56 - n amplify the analog signals input from the wireless interface units 55 - 1 to 55 - n to predetermined powers, and output the results to the antennas 34 - 1 to 34 - n .

[0156] In addition, the amplifier units 56 - 1 to 56 - n amplify the signals input from the antennas 34 - 1 to 34 - n to predetermined powers at the time of reception, and output the signals to the wireless interface units 55 - 1 to 55 - n .

[0157] At least a part of at least one of the functions at the time of transmission or the functions at the time of reception of the amplifier units 56 - 1 to 56 - n may be included in the wireless interface units 55 - 1 to 55 - n .

[0158] In addition, at least a part of at least one of the function at the time of transmission or the function at the time of reception of the amplifier units 56 - 1 to 56 - n may be a component external to the communication unit.

[0159] <Configuration example of terminal device>

[0160] Next, we will refer to Figure 7 The block diagram in describes a configuration example of the terminal device 12.

[0161] The terminal device 12 includes a control unit 71, a power supply unit 72, a communication unit 73, and antennas 74-1 to 74-m, and has components corresponding to those already mentioned in reference. Figure 6 The configurations of the control unit 31, the power supply unit 32, the communication unit 33, and the antennas 34-1 to 34-n in the wireless base station 11 are described.

[0162] The control unit 71 controls the communication unit 73 to receive the sounding trigger frame and the NDP frame, and measures the CQI when receiving the NDP frame.

[0163] Then, the control unit 31 generates a CQI feedback frame including the measurement result of the CQI, controls the communication unit 73 , and transmits the CQI feedback frame to the radio base station 11 .

[0164] The communication unit 73 is controlled by the control unit 71 and performs various communication processes.

[0165] More specifically, the communication unit 73 includes a wireless control unit 91 , a data processing unit 92 , a modulation and demodulation unit 93 , a spatial signal processing unit 94 , wireless interface units 95 - 1 to 95 - n , amplifier units 96 - 1 to 96 - n , and a channel estimation unit 97 .

[0166] Note that the wireless control unit 91, the data processing unit 92, the modulation and demodulation unit 93, the spatial signal processing unit 94, the wireless interface units 95-1 to 95-n, the amplifier units 96-1 to 96-n, and the channel estimation unit 97 have the same Figure 6 The described wireless control unit 51, data processing unit 52, modulation and demodulation unit 53, spatial signal processing unit 54, wireless interface units 55-1 to 55-n, amplifier units 56-1 to 56-n and channel estimation unit 57 correspond to the configuration, so their description will be omitted.

[0167] In addition, since the power supply unit 72 and the antennas 74-1 to 74-m have the same Figure 6 The power supply unit 32 and the antennas 34 - 1 to 34 - m are described as having the same configuration, and thus description thereof will be omitted.

[0168] <Configuration example of detection trigger frame>

[0169] Next, we will refer to Figure 8 Describes a configuration example of a detection trigger frame.

[0170] Starting from the left side of the figure, the detection trigger frame includes: 2 octets of frame control, 2 octets of duration, 6 octets of receiver address (RA), 6 octets of transmitter address (TA), 1 octet of detection conversation token, 1 octet of the number of AP information, n pieces of AP information in units of 2 octets, n pieces of STA information in units of 4 octets, and 4 octets of frame check sequence (FCS).

[0171] The frame control is information specifying a frame type, and here, information specifying that the frame is a detection trigger frame is stored.

[0172] In the duration, information indicating a transmission period of a radio wave for transmitting a probe trigger frame is stored.

[0173] The information of the receiver's address is stored in the RA, and the information of the sender's address is stored in the TA.

[0174] From the left side in the figure, the detection dialogue token includes: 1 bit of reserved (reserved area), 1 bit of HE, and 6 bits of detection dialogue token number.

[0175] The HE stores information for distinguishing a mode between a high efficiency (HE) mode and a very high throughput (VHT) mode.

[0176] The probe dialog token number stores number information used to associate the probe trigger frame with the corresponding NDP.

[0177] The number of AP information stores information indicating the number of pieces of AP information.

[0178] From the left side of the figure, the AP information includes: 6 bits of BSS color, 6 bits of NDP transmission period, and 6 bits of NDP transmission flow.

[0179] The BSS color stores an identifier identifying the wireless base station 11 .

[0180] The NDP transmission period stores information for specifying the transmission timing of the NDP frame, and stores, for example, information about the time from the reception of the sounding trigger frame to the reception of the NDP frame.

[0181] The NDP transmission stream stores information (spatial information) associated with the transmission stream when the NDP frame is transmitted, and stores, for example, information of a row of a mapping matrix indicating a long training field (LTF) of the NDP frame to be used.

[0182] Here, the long training field (LTF) is a field included in the NDP frame and stores information for performing a synchronization process for a reception signal.

[0183] For example, when the wireless base stations 11-1 and 11-2 use two antennas each for sounding to transmit an NDP frame, the mapping matrix of the LTF in the NDP frame is, for example, as follows: Fig. 9 The 4-row × 4-column matrix representation shown.

[0184] Notice, Fig. 9 The mapping matrix is ​​a matrix including four rows and four columns, where the top row from the left is 1, -1, 1, 1, the second row from the left is 1, 1, -1, 1, the third row from the left is 1, 1, 1, -1, and the bottom row from the left is -1, 1, 1, 1.

[0185] Here, the configuration in which the wireless base stations 11 - 1 and 11 - 2 each use two antennas to transmit the NDP frame corresponds to the case in which one wireless base station 11 uses four antennas to transmit the NDP frame.

[0186] In the case of one wireless base station 11, mapping matrices may be assigned to antennas 1, 2, 3, and 4 from the uplink so that NDP frames may be transmitted to each antenna separately.

[0187] Similarly, by notifying rows in the NDP transmission stream of the AP information of the detection trigger frame, where the top two rows are assigned to the wireless base station 11-1 and the bottom two rows are assigned to the wireless base station 11-2, even when the NDP frames are sent at the same timing, the NDP frames can be sent separately in different transmission streams for each antenna of the wireless base stations 11-1, 11-2.

[0188] The STA information includes: 11 bits of AID 11, 14 bits of partial BW information, 2 bits of feedback type and Ng, 1 bit of ambiguity elimination, 1 bit of codebook size, and 3 bits of Nc.

[0189] The AID 11 stores an identifier that identifies the terminal device 12 .

[0190] The partial BW information stores information specifying a resource unit (RU) range used when sending CQI feedback.

[0191] Feedback Type and Ng stores the CQI feedback method and information specifying Ng about how many adjacent subcarrier matrix information should be transmitted as the same value (single user (SU) or multi-user (MU), Ng=4, 16).

[0192] Disambiguation stores information for preventing ambiguity of legacy terminals.

[0193] The codebook size stores information specifying a quantization resolution of a CQI feedback value.

[0194] Nc stores information about the number of streams used to calculate a CQI feedback signal.

[0195] The frame check sequence (FCS) stores information about the error correction code.

[0196] Figure 8 The detection trigger frame shown has a configuration in which the number of AP information and n pieces of AP information are added to Fig.10 In the conventional NDP-A frame shown.

[0197] That is, the detection trigger frame is as follows Figure 8 The illustrated configuration has a configuration similar to that of a conventional NDP-A frame, and further, stores information specifying a transmission timing and a transmission flow when each NDP frame of the wireless base station 11 is transmitted.

[0198] In addition, a probe trigger frame is transmitted from the wireless base station 11 - 1 as the master station to the wireless base station 11 as the slave station and the terminal devices 12 - 1 to 12 - 4 .

[0199] Therefore, the wireless base stations 11 - 1 , 11 - 2 and the terminal devices 12 - 1 to 12 - 4 recognize, in units of the wireless base station 11 , the transmission timing and the transmission flow at which the NDP frame is transmitted in both the two wireless base stations 11 - 1 , 11 - 2 , respectively.

[0200] Therefore, the wireless base stations 11 - 1 , 11 - 2 may cooperate to transmit the NDP frame at the same timing, or the wireless base stations 11 - 1 , 11 - 2 may independently transmit the NDP frame at different timings.

[0201] Note that as to whether the wireless base stations 11-1 and 11-2 can cooperate with each other to send NDP frames at the same time, the wireless base station 11-1 can exchange capability information with the wireless base station 11-2 and the terminal device 12 in advance, and determine whether the wireless base stations 11-1 and 11-2 can cooperate with each other to send NDP frames at the same time based on the capability information of the wireless base station 11-2 and the terminal device 12. In addition, if the wireless base stations 11-1 and 11-2 can cooperate to send NDP frames at the same time, it can be selected whether to send NDP frames at the same time or to send NDP frames separately at independent timings. Therefore, even if the wireless base stations 11-1 and 11-2 can cooperate to send NDP frames at the same time, the capability information can be used to determine whether to send NDP frames at the same time.

[0202] In addition, the wireless base station 11 as the master station may be any one of the wireless base stations 11-1, 11-2, and it is sufficient for the wireless base station 11 as the master station to send a detection trigger frame when each wireless base station needs to perform detection.

[0203] For example, each of wireless base stations 11-1, 11-2 may be caused to repeatedly probe at a predetermined cycle, and in this case, it is sufficient for the wireless base station as the master wireless base station 11 to transmit a probe trigger frame when probing is started at each of wireless base stations 11-1, 11-2.

[0204] <Communication Processing in First Embodiment>

[0205] Next, we will refer to Figures 11 to 13 The flowchart describes the communication processing according to the first embodiment.

[0206] In addition, in the description of the communication processing in the first embodiment, reference will also be made to Figure 3 and Figure 4 The timing diagram in Figure 1 is used to describe the timing.

[0207] Here, an example of communication processing in a communication system including the wireless base stations 11 - 1 , 11 - 2 and the terminal device 12 of any one of the terminal devices 12 - 1 to 12 - 4 will be described.

[0208] Note that Figure 3 and Figure 4 In the timing diagram of , the wireless base station AP1 corresponds to the wireless base station 11 - 1 , the wireless base station AP2 corresponds to the wireless base station 11 - 2 , and the terminal device STA1 corresponds to the terminal device 12 .

[0209] In addition, in the description of the communication processing in the first embodiment, for example, as an operation object, the control unit 31 of the wireless base station 11-1 is referred to as the control unit 31-1, and the control unit 31 of the wireless base station 11-2 is referred to as the control unit 31-2, and in other configurations, the control unit is distinguished as whether it is the wireless base station 11-1 or the wireless base station 11-2 by adding "-" in a similar manner and by a subsequent code.

[0210] Furthermore, only the operations of the communication units 33, 73 of the wireless base station 11 and the terminal device 12 will be described as being controlled by the control units 31, 71, respectively, to transmit or receive a predetermined frame, and a detailed description of the operations will be omitted.

[0211] In step S11( Fig.11 ), the control unit 31-1 of the wireless base station 11-1 as the master station generates a detection trigger frame, and controls the communication unit 33-1 to send the detection trigger frame to the wireless base station 11-2 and the terminal device 12 as the slave station.

[0212] In step S31( Fig.12 ), the control unit 31-2 of the wireless base station 11-2 controls the communication unit 33-2 to receive the detection trigger frame transmitted from the wireless base station 11-1.

[0213] In step S51 ( Fig.13 ), the control unit 71 of the terminal device 12 controls the communication unit 73 to receive the detection trigger frame sent from the wireless base station 11-1.

[0214] That is to say, through the processing of the above steps S11, S31 and S51, the Figure 3 Time t21 or Figure 4 The process shown at time t31 in FIG.

[0215] In step S12 ( Fig.11 ), the control unit 31-1 of the wireless base station 11-1 generates an NDP frame, and controls the communication unit 33-1 to send the NDP frame to the terminal device 12 at the sending timing specified by the AP information specifying its own wireless base station 11 and in the sending stream specified by the AP information in the detection trigger frame.

[0216] In step S32 ( Fig.12), the control unit 31-2 of the wireless base station 11-2 generates an NDP frame, and controls the communication unit 33-2 to send the NDP frame to the terminal device 12 at the sending timing specified by the AP information specifying its own wireless base station 11 and in the sending stream specified by the AP information in the detection trigger frame.

[0217] In step S52 ( Fig.13 ), the control unit 71 of the terminal device 12 determines whether multiple wireless base stations 11-1, 11-2 cooperate with each other to send NDP frames at the same timing based on the AP information of the detection trigger frame.

[0218] In step S52 , in the case where the plurality of wireless base stations 11 - 1 , 11 - 2 cooperate with each other to transmit the NDP frame at the same timing, the process proceeds to step S53 .

[0219] In step S53, the control unit 71 of the terminal device 12 controls the communication unit 73 to receive the NDP frame transmitted from the wireless base stations 11-1, 11-2 in the designated transmission stream at the designated transmission timing, and measures the CQI.

[0220] That is, in the case where the plurality of wireless base stations 11-1, 11-2 cooperate with each other to transmit NDP frames at the same timing, Figure 3 At time t22 in the process, step S12 ( Fig.11 ) and S32( Fig.12 ) so that the terminal device 12 receives NDP frames from the wireless base stations 11-1 and 11-2 at the same time and measures CQI at the same time.

[0221] On the other hand, in step S52, when the plurality of wireless base stations 11-1 and 11-2 independently transmit NDP frames at different timings, the process proceeds to step S55.

[0222] In step S55 , the control unit 71 of the terminal device 12 controls the communication unit 73 to receive the NDP frame transmitted in the designated transmission stream at the designated transmission timing from the wireless base station 11 - 1 , and measures the CQI.

[0223] In step S56 , the control unit 71 of the terminal device 12 controls the communication unit 73 to receive the NDP frame transmitted in the designated transmission stream at the designated transmission timing from the wireless base station 11 - 2 , and measures the CQI.

[0224] That is, in the case where a plurality of wireless base stations 11-1, 11-2 independently transmit NDP frames at different timings, for example, Figure 4 As shown, step S12 ( Fig.11) so that the terminal device 12 receives the NDP frame from the wireless base station 11-1 and measures the CQI of the wireless base station 11-1.

[0225] Thereafter, for example, Figure 4 As shown, step S32 ( Fig.12 ) so that the terminal device 12 receives the NDP frame from the wireless base station 11-2 and measures the CQI of the wireless base station 11-2.

[0226] In this case, the terminal device 12 receives NDP frames individually and independently from the wireless base stations 11 - 1 , 11 - 2 at different timings, and measures each CQI.

[0227] Here, since the transmission timings of the NDP frames from the wireless base stations 11-1 and 11-2 are different from each other, the NDP frames can be transmitted from the wireless base stations 11-1 and 11-2 in the same transmission flow.

[0228] Therefore, in this case, if any particular transmission stream is determined, then the reference Figure 8 The information about the NDP transmission stream of the AP information in the described detection trigger frame may be omitted or deleted, and may be information specifying a specific transmission stream.

[0229] In step S54 ( Fig.13 ), the control unit 71 of the terminal device 12 generates a CQI feedback frame based on the CQI of the wireless base stations 11-1 and 11-2, and controls the communication unit 73 to send the CQI feedback frame to the wireless base stations 11-1 and 11-2 through a specified sending method at a timing after receiving the last sent NDP frame of information about the detection trigger frame.

[0230] In step S13 ( Fig.11 ), the control unit 31-1 of the wireless base station 11-1 controls the communication unit 33-1 to receive the CQI feedback frame sent from the terminal device 12.

[0231] In step S33 ( Fig.12 ), the control unit 31-2 of the wireless base station 11-2 controls the communication unit 33-2 to receive the CQI feedback frame sent from the terminal device 12.

[0232] Through the above processing, such as Figure 3 Time t23 or Figure 4 As shown at time t34 in FIG. 1 , a CQI feedback frame is transmitted from the terminal device 12 to the wireless base stations 11 - 1 and 11 - 2, and the wireless base stations 11 - 1 and 11 - 2 receive the CQI feedback frame.

[0233] In addition, the wireless base stations 11 - 1 , 11 - 2 can achieve optimal beamforming for the terminal device 12 by setting a transfer function based on the CQI in the received CQI feedback frame.

[0234] In addition, through this series of processing, information about the sending timing and sending flow of the NDP frame can be sent to the wireless base station 11-2 and the terminal device 12 as slave stations in one detection trigger frame without sending a trigger frame every time an NDP frame is sent, so that the CQI of the wireless base stations 11-1 and 11-2 can be quickly collected in the terminal device 12.

[0235] In addition, since the sending timing of the NDP frame of each wireless base station 11 can be individually set by detecting the trigger frame, detection can be achieved even if multiple wireless base stations 11-1, 11-2 are configured so that they cannot send NDP-A frames or NDP frames at a coordinated and synchronized timing.

[0236] As a result, the time required to collect the detection information of a plurality of wireless base stations in the terminal device can be shortened, and a decrease in the following accuracy can be suppressed.

[0237] Note that, above, an example has been described in which the terminal device 12 sends a CQI feedback frame by a method whereby any of the wireless base stations 11-1, 11-2 can receive the CQI feedback frame, but the CQI feedback frame can be sent to any of the wireless base stations 11-1, 11-2.

[0238] In this case, among the radio base stations 11 - 1 , 11 - 2 , one radio base station 11 that has received the CQI feedback frame transmits the CQI feedback frame to the other radio base station 11 .

[0239] Through the above reference Figure 8 The feedback type and Ng of the STA information in the described sounding trigger frame are used to specify whether the terminal device 12 sends the CQI feedback frame to both wireless base stations 11-1 and 11-2 or to either one of them.

[0240] <<3. Application Examples of First Embodiment>>

[0241] In the above, it has been described that Figure 8 However, in the frame control, a configuration may be applied such that the identifier frame as the NDP-A frame is registered, and the reserved 2-bit information as the detection dialogue token and HE may be used to register the detection trigger frame as such. Figure 8 The frame identification of the detection trigger frame is shown as a normal NDP-A frame and an extended NDP-A frame.

[0242] That is, regarding reservation, in the case of 0, when HE is 0, the frame is considered to be a normal VHT NDP announcement frame, and when HE is 1, the frame is considered to be a HE NDP announcement frame.

[0243] Then, in the case where Reserved is 1, the frame is considered to be a detection trigger frame when HE is 0, and is set to the Reserved state when HE is 1.

[0244] Thus, when the probe trigger frame is read in the frame control, by identifying it as an NDP-A frame and then reading the probe dialog token, it can be identified whether it is a VHT NDP announcement frame, a HE NDP announcement frame, or a probe trigger frame.

[0245] In addition, in the above, it has been described that the BSS color is Figure 8 The AP information in the detection trigger frame is used as an example of information for identifying the wireless base station 11, but as long as the wireless base station 11 can be identified, the information may be other information, and may be, for example, a BSSID.

[0246] <<4. Second embodiment>>

[0247] In the above, the detection by the plurality of wireless base stations 11 for one terminal device 12 has been described. However, the plurality of wireless base stations 11 may perform detection for a plurality of terminal devices 12.

[0248] In the case where a plurality of wireless base stations 11 perform sounding for a plurality of terminal devices 12, a beamforming report polling (BFRP) trigger frame is newly defined in addition to the sounding trigger frame.

[0249] The BFRP trigger frame is a frame transmitted from the wireless base station 11-1 as the master to the plurality of terminal devices 12 after all wireless base stations 11 transmit NDP frames. The BFRP trigger frame includes information indicating a method of returning a CQI feedback frame to each of the plurality of terminal devices 12.

[0250] More specifically, in the case where a plurality of wireless base stations are configured to be able to transmit NDP frames at coordinated and synchronized timing and two terminal devices 12-1, 12-2 are used as the terminal device 12, processing such as Fig.15 As shown in the timing diagram.

[0251] That is, at time t51, the wireless base station 11-1 as the master station transmits a probe trigger frame describing the transmission timing and transmission parameters of the NDP frame to the wireless base station 11-2 and the terminal devices 12-1, 12-2.

[0252] Here, the wireless base station 11-2 and the terminal devices 12-1, 12-2 receive the detection trigger frame and recognize the transmission timing and transmission parameters of the NDP frame.

[0253] At time t52, each of the wireless base stations 11-1, 11-2 transmits an NDP frame in the designated transmission stream at the transmission timing designated by the probe trigger frame.

[0254] Here, the terminal devices 12-1, 12-2 receive the NDP transmitted in each transmission stream of the wireless base stations 11-1, 11-2, and measure each CQI.

[0255] At time t53, the wireless base station 11-1 as the master station transmits a BFRP trigger frame describing transmission parameters of a CQI feedback frame to the terminal devices 12-1, 12-2.

[0256] At this time, the terminal devices 12-1 and 12-2 receive the BFRP trigger frame describing the transmission parameters of the CQI feedback frame.

[0257] At time t54, the terminal devices 12-1, 12-2 generate a CQI feedback frame including the CQI as the measurement result based on the return method described in the BFRP trigger frame, and transmit the CQI feedback frame to the radio base stations 11-1, 11-2.

[0258] Here, the wireless base stations 11-1, 11-2 receive the transmitted CQI feedback frames, derive the optimal transfer function of the transmission path to the terminal devices 12-1, 12-2 based on each CQI, and implement the optimal beamforming to the terminal devices 12-1, 12-2.

[0259] In addition, in the case where the plurality of wireless base stations 11-1 and 11-2 are configured to be unable to transmit NDP frames at coordinated and synchronized timing (that is, the plurality of wireless base stations 11-1 and 11-2 are each configured to transmit NDP frames at different timings), processing such as Fig.16 As shown in the timing diagram.

[0260] That is to say, Fig.16 As shown in the timing diagram in , at time t71, the wireless base station 11-1 sends a detection trigger frame describing the transmission timing and transmission parameters of the NDP frame to the wireless base station 11-2 and the terminal devices 12-1 and 12-2.

[0261] Here, the wireless base station 11-2 and the terminal devices 12-1, 12-2 receive the detection trigger frame and recognize the transmission timing and transmission parameters of the NDP frame.

[0262] At time t72, the wireless base station 11-1 transmits the NDP in the designated transmission stream at the transmission timing designated by the probe trigger frame.

[0263] Here, the terminal devices 12-1 and 12-2 receive the NDP frames transmitted in the specified transmission stream from the radio base station 11-1 at the transmission timing specified by the sounding trigger frame, and measure the CQI of the radio base station 11-1.

[0264] At time t73, the radio base station 11-2 transmits an NDP frame in the specified transmission stream at the transmission timing specified by the sounding trigger frame.

[0265] Here, the terminal devices 12-1 and 12-2 receive the NDP frames transmitted in the specified transmission stream from the radio base station 11-2 at the transmission timing specified by the sounding trigger frame, and measure the CQI of the radio base station 11-2.

[0266] At time t74, the radio base station 11-1 as the master station transmits a BFRP trigger frame describing the return method of the CQI feedback frame to the terminal devices 12-1 and 12-2.

[0267] At this time, the terminal devices 12-1 and 12-2 receive the BFRP trigger frame describing the return method of the CQI feedback frame.

[0268] At time t75, the terminal devices 12-1 and 12-2 generate a CQI feedback frame including the CQI as the measurement result based on the return method described in the BFRP trigger frame, and transmit the CQI feedback frame to the radio base stations 11-1 and 11-2.

[0269] Here, the radio base stations 11-1 and 11-2 receive the transmitted CQI feedback frames, obtain the optimal transfer function of the transmission path to the terminal devices 12-1 and 12-2 based on each CQI, and implement the optimal beamforming to the terminal devices 12-1 and 12-2.

[0270] <Configuration Example of BFRP Trigger Frame>

[0271] Next, with reference to Fig.17 describe the configuration example of the BFRP trigger frame.

[0272] The BFRP trigger frame includes: 2-octet frame control, 2-octet duration, 6-octet receiver address (RA), 6-octet transmitter address (TA), 8 (or more) octets of common information, n pieces of user information in units of 5 octets, variable-length padding, and 4-octet frame check sequence (FCS).

[0273] Among them, the frame control, duration, RA, TA, and FCS have configurations similar to those in Figure 8 the sounding trigger frame, and thus their descriptions will be omitted. In addition, since the padding has no function, its description will be omitted.

[0274] The common information includes: 4 bits of trigger type, 12 bits of length, and 48 (or more) bits of FP.

[0275] The trigger type stores information indicating the type of trigger, and the BFRP is specified in the trigger type.

[0276] The length stores information on the data length of the public information.

[0277] FP (Feedback Parameters) stores CQI feedback transmission parameters common to all terminal devices 12 .

[0278] The user information includes: 12 bits of starting AID, 9 bits of reserved, 4 bits of feedback type, 7 bits of reserved, 7 bits of target RSSI, and 1 bit of multiplexing flag.

[0279] The start AID stores identification information that identifies the terminal device 12 that is designated to return CQI feedback.

[0280] The feedback type stores information specifying a return method in a CQI feedback frame unique to the terminal device 12 specified by the start AID. Specific information specifying a return method for CQI feedback is, for example, a resource request type that requests feedback only from a terminal device 12 having data to be sent to the wireless base station 11.

[0281] The target RSSI stores the target RSSI value of the CQI feedback signal. The terminal device 12 controls the transmission power based on this value.

[0282] The multiplexing flag stores a flag indicating whether multiple terminal devices 12 use the same subcarrier to return CQI feedback.

[0283] <Communication Processing in Second Embodiment>

[0284] Next, we will refer to Figures 18 to 20 The flowchart in describes the communication processing according to the second embodiment. In addition, in the description of the communication processing in the second embodiment, reference will also be made to Fig.15 and Fig.16 The timing diagram in Figure 1 is used to describe the timing.

[0285] In step S71( Fig.18 ), the control unit 31-1 of the wireless base station 11-1 as the master station generates a detection trigger frame, and controls the communication unit 33-1 to send the detection trigger frame to the wireless base station 11-2 as the slave station and the terminal devices 12-1, 12-2.

[0286] In step S91( Fig.19), the control unit 31-2 of the wireless base station 11-2 controls the communication unit 33-2 to receive the detection trigger frame transmitted from the wireless base station 11-1.

[0287] In step S111( Fig. 20 ), the control units 71-1, 71-2 of the terminal devices 12-1, 12-2 control the communication units 73-1, 73-2 to receive the detection trigger frame sent from the wireless base station 11-1.

[0288] That is to say, through the processing of the above steps S71, S91 and S111, the Fig.15 Time t51 or Fig.16 The process shown at time t71 in FIG.

[0289] In step S72 ( Fig.18 ), the control unit 31-1 of the wireless base station 11-1 generates an NDP frame, and controls the communication unit 33-1 to send the NDP frame to the terminal device 12 at the sending timing specified by the AP information specifying its own wireless base station 11 and in the sending stream specified in the detection trigger frame.

[0290] In step S92 ( Fig.19 ), the control unit 31-2 of the wireless base station 11-2 generates an NDP frame, and controls the communication unit 33-2 to send the NDP frame to the terminal device 12 at the sending timing specified by the AP information specifying its own wireless base station 11 and in the sending stream specified in the detection trigger frame.

[0291] In step S112 ( Fig. 20 ), the control units 71-1, 71-2 of the terminal devices 12-1, 12-2 determine whether the plurality of wireless base stations 11-1, 11-2 cooperate with each other to send NDP frames at the same timing based on the AP information of the detection trigger frame.

[0292] In step S112 , in the case where the plurality of wireless base stations 11 - 1 , 11 - 2 cooperate with each other to transmit the NDP frame at the same timing, the process proceeds to step S113 .

[0293] In step S113, the control units 71-1, 71-2 of the terminal devices 12-1, 12-2 control the communication units 73-1, 73-2, respectively, to receive the NDP frames transmitted from the wireless base stations 11-1, 11-2.

[0294] That is, in the case where the plurality of wireless base stations 11-1, 11-2 cooperate with each other to transmit NDP frames at the same timing, Fig.15 At time t52 in step S72 ( Fig.18 ) and S92( Fig.19) so that the terminal devices 12-1 and 12-2 simultaneously receive NDP frames from the wireless base stations 11-1 and 11-2 and simultaneously measure CQI.

[0295] On the other hand, in step S112, when the plurality of wireless base stations 11-1 and 11-2 independently transmit NDP frames at different timings, the process proceeds to step S117.

[0296] In step S117, the control units 71-1, 71-2 of the terminal devices 12-1, 12-2 control the communication units 73-1, 73-2, respectively, to receive the NDP frame transmitted from the wireless base station 11-1.

[0297] In step S118, the control units 71-1, 71-2 of the terminal devices 12-1, 12-2 control the communication units 73-1, 73-2, respectively, and receive the NDP frame transmitted from the wireless base station 11-2, and measure the CQI.

[0298] That is, in the case where a plurality of wireless base stations 11-1, 11-2 independently transmit NDP frames at different timings, for example, Fig.16 As shown, at time t72, step S72 ( Fig.18 ) so that each of the terminal devices 12-1, 12-2 receives the NDP frame from the wireless base station 11-1 and measures the CQI of the wireless base station 11-1.

[0299] In addition, for example, Fig.16 As shown, step S92 ( Fig.19 ) so that each of the terminal devices 12-1, 12-2 receives the NDP frame from the wireless base station 11-2 and measures the CQI of the wireless base station 11-2.

[0300] That is, in this case, each of the terminal devices 12-1, 12-2 receives NDP frames from the wireless base stations 11-1, 11-2 respectively and independently at different timings, and measures each CQI.

[0301] In step S114 , the terminal devices 12 - 1 , 12 - 2 determine whether to perform probing for a plurality of terminal devices 12 based on the STA information of the probe trigger frame.

[0302] Here, since the detection is performed for a plurality of terminal devices 12 - 1 , 12 - 2 , in step S114 , it is considered that the detection is performed for a plurality of terminal devices 12 , and the process proceeds to step S115 .

[0303] In step S115, the control units 71-1, 71-2 of the terminal devices 12-1, 12-2 control the communication units 73-1, 73-2 to determine whether a BFRP trigger frame transmitted from the wireless base station 11-1 as the master has been received, and repeat similar processing until a BFRP trigger frame is received.

[0304] On the other hand, in step S73 ( Fig.18 ), the control unit 31-1 of the wireless base station 11-1 as the master station generates a BFRP trigger frame and controls the communication unit 33-1 to send the BFRP trigger frame to the terminal devices 12-1, 12-2.

[0305] Through the above processing, such as Fig.15 Time t53 or Fig.16 As shown at time t74 in FIG. 1 , a BFRP trigger frame is transmitted from the wireless base station 11 - 1 to the terminal devices 12 - 1 and 12 - 2 .

[0306] Through the process of step S73, the BFRP trigger frame is transmitted from the wireless base station 11-1 as the master station, and the control units 71-1, 71-2 of the terminal devices 12-1, 12-2 control the communication units 73-1 and 73-2, respectively, to receive the BFRP trigger frame.

[0307] Therefore, in step S115 ( Fig. 20 ), it is considered that the BFRP trigger frame has been received, and the processing enters step S116.

[0308] In step S116, each of the terminal devices 12-1, 12-2 generates a CQI feedback frame according to the CQI of the wireless base stations 11-1, 11-2 based on the return method specified in the received BFRP trigger frame.

[0309] Then, the terminal devices 12-1, 12-2 control the communication units 73-1, 73-2, respectively, to transmit the CQI feedback frames to the wireless base stations 11-1, 11-2.

[0310] In step S74 ( Fig.18 ), the control unit 31-1 of the wireless base station 11-1 controls the communication unit 33-1 to receive the CQI feedback frame sent from the terminal devices 12-1, 12-2.

[0311] In step S93 ( Fig.19 ), the control unit 31-2 of the wireless base station 11-2 controls the communication unit 33-2 to receive the CQI feedback frame sent from the terminal devices 12-1, 12-2.

[0312] Through the above processing, such as Fig.15 Time t54 or Fig.16 As shown at time t75 in FIG. 1 , a CQI feedback frame is transmitted from the terminal devices 12 - 1 and 12 - 2 to the wireless base stations 11 - 1 and 11 - 2, and the wireless base stations 11 - 1 and 11 - 2 receive the CQI feedback frame.

[0313] In addition, by setting the transfer function based on the CQI in the received CQI feedback frame, each of the wireless base stations 11-1, 11-2 can achieve optimal beamforming for the terminal devices 12-1, 12-2.

[0314] Note that, in the case where detection has not been performed for a plurality of terminal devices 12 in step S114, the processing of step S115 is skipped.

[0315] That is, in this case, since the detection is a process performed on one terminal device 12, the process of step S115 is skipped, and substantially, reference has been made to the Fig.13 The detection described is a process similar to the communication process performed for one terminal device 12 .

[0316] As described above, through a series of processing, also for multiple terminal devices 12-1, 12-2, information about the sending timing and sending flow of the NDP frame can be sent to the wireless base station 11-2 serving as a slave station and multiple terminal devices 12-1, 12-2 in one detection trigger frame, without sending a trigger frame every time an NDP frame is sent, so that the CQI of the wireless base stations 11-1, 11-2 can be quickly collected in the terminal device 12.

[0317] In addition, since the sending timing of the NDP frame of each wireless base station 11 can also be set separately for multiple terminal devices 12-1, 12-2 through the detection trigger frame, detection can be achieved even if the multiple wireless base stations 11-1, 11-2 are configured to be unable to send NDP-A frames or NDP frames at a coordinated and synchronized timing.

[0318] Furthermore, even if sounding is performed for a plurality of terminal devices 12 and CQI feedback frames are transmitted at the same timing, the wireless base station 11 can distinguish and receive corresponding CQI feedback frames by the return method specified by the BFRP trigger frame.

[0319] Note that, in the above, an example has been described in which two terminal devices 12-1, 12-2 are used as the terminal device 12, but the terminal device 12 may be two or more, may be four terminal devices 12-1 to 12-4, or may be four or more. In addition, the wireless base station 11 may be two or more wireless base stations 11-1, 11-2.

[0320] In the above, an example has been described in which each terminal device 12-1, 12-2 sends a CQI feedback frame by a method whereby any wireless base station among wireless base stations 11-1, 11-2 can receive the CQI feedback frame, but the CQI feedback frame can be sent to any one of wireless base stations 11-1, 11-2.

[0321] In this case, among the radio base stations 11 - 1 , 11 - 2 , one radio base station 11 that has received the CQI feedback frame transmits the CQI feedback frame to the other radio base station 11 .

[0322] Through the above reference Fig.17 The feedback type of user information in the described BFRP trigger frame is used to specify whether each of the terminal devices 12-1, 12-2 sends a CQI feedback frame to both wireless base stations 11-1, 11-2 or to either one of the two.

[0323] As a result, the time required to collect the detection information of a plurality of wireless base stations in a plurality of terminal devices can be shortened, and a decrease in the following accuracy can be suppressed.

[0324] <<5. Example of execution by software>>

[0325] Incidentally, the above series of processing may also be performed by hardware. However, this series of processing may also be performed by software. In the case where a series of processing is performed by software, a program included in the software is installed from a recording medium to a computer included in dedicated hardware, for example, a general-purpose computer that can perform various functions by installing various programs, etc.

[0326] Fig.21 1001. An example of a configuration of a general-purpose computer is shown. This personal computer has a built-in central processing unit (CPU) 1001. An input and output interface 1005 is connected to the CPU 1001 via a bus 1004. A read only memory (ROM) 1002 and a random access memory (RAM) 1003 are connected to the bus 1004.

[0327] The input and output interface 1005 is connected to an input unit 1006 including an input device such as a keyboard or a mouse for inputting an operation command by a user, an output unit 1007 outputting an image of a processing operation screen or a processing result to a display device, a storage unit 1008 including a hard disk drive etc. for storing programs and various data, and a communication unit 1009 including a local area network (LAN) adapter etc. and performing communication processing via a network represented by the Internet. In addition, the input and output interface 1005 is connected to a drive 1010, which reads and writes data with respect to a removable storage medium 1011 such as a magnetic disk (including a floppy disk), an optical disk (including a compact disk read-only memory (CD-ROM) and a digital versatile disk (DVD)), a magneto-optical disk (including a mini-disc (MD)), or a semiconductor memory.

[0328] The CPU 1001 reads out a program stored in the ROM 1002 or a removable storage medium 1011 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, installs in the storage unit 1008, and executes various processes according to the program loaded from the storage unit 1008 into the RAM 1003. In addition, the RAM 1003 also appropriately stores data and the like necessary for the CPU 1001 to execute various processes.

[0329] In the computer configured as described above, for example, the CPU 1001 loads a program stored in the storage unit 1008 into the RAM 1003 via the input and output interface 1005 and the bus 1004 and executes the program, so that the above-described series of processing is performed.

[0330] For example, the program executed by the computer (CPU 1001) can be provided by being recorded on the removable storage medium 1011 as a package medium, etc. In addition, the program can be provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting.

[0331] In the computer, by mounting the removable storage medium 1011 to the drive 1010, the program can be installed in the storage unit 1008 via the input and output interface 1005. In addition, the program can be received by the communication unit 1009 via a wired or wireless transmission medium and installed in the storage unit 1008. In addition, the program can be pre-installed in the ROM 1002 or the storage unit 1008.

[0332] Note that the program executed by the computer may be a program of time-series processing according to the order described in this specification, or may be a program of processing in parallel or at necessary timing such as when making a phone call.

[0333] Notice, Fig.21 CPU 1001 implementation in Figure 6 The control unit 31 and Figure 7 The functions of the control unit 71 in.

[0334] In addition, in this specification, a system refers to a group of multiple constituent elements (devices, modules (components), etc.), and it is not important whether all the constituent elements are in the same housing. Therefore, multiple devices housed in separate housings and connected via a network and a device in which multiple modules are housed in one housing are both systems.

[0335] Note that the embodiments of the present disclosure are not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present disclosure.

[0336] For example, in the present disclosure, a configuration of cloud computing may be adopted in which one function is shared by a plurality of devices via a network and is processed cooperatively.

[0337] In addition, each step described in the above flowchart may be performed by one device or shared by multiple devices.

[0338] Furthermore, in the case where a plurality of processes are included in one step, the plurality of processes included in one step may be executed by one device or may be shared and executed by a plurality of devices.

[0339] Note that the present disclosure can adopt the following configurations.

[0340] <1> A wireless base station, comprising

[0341] A control unit performs control to transmit a start frame instructing other wireless base stations to perform channel measurement when performing channel measurement with a terminal device.

[0342] <2> according to <1> The wireless base station,

[0343] The start frame includes: identification information of the other wireless base station; and at least one of timing information or space information for the other wireless base station to send a frame for channel measurement, wherein the frame for channel measurement is a frame used for channel measurement.

[0344] <3> according to <2> The wireless base station,

[0345] In which, when the wireless base station and the other wireless base stations send channel measurement frames at the same timing, the start frame includes timing information and space information for the other wireless base stations to send channel measurement frames at the same timing as the timing of the wireless base station sending the channel measurement frames.

[0346] <4> according to <2> The wireless base station,

[0347] In which, when the wireless base station and the other wireless base stations do not send channel measurement frames at the same timing, the start frame includes timing information for the other wireless base station to send channel measurement frames at a timing different from the timing of the wireless base station sending the channel measurement frames.

[0348] <5> according to <1> to <1> The wireless base station described in any one of claims ,

[0349] wherein the start frame includes, as transmission method information, information indicating a transmission method when the terminal device transmits a channel measurement result as a result of the channel measurement to the wireless base station, and

[0350] The control unit performs control to receive a channel measurement result transmitted from the terminal device based on the transmission method information.

[0351] <6> according to <5> The wireless base station,

[0352] Wherein, in the case where the sending method information is information instructing the terminal device to send a channel measurement result to any wireless base station including the wireless base station,

[0353] The control unit of the wireless base station to which the channel measurement result is transmitted from the terminal device performs control to receive the channel measurement result from the terminal device and also transmits the received channel measurement result to the other wireless base stations, and

[0354] The control unit of the radio base station to which the channel measurement result is transmitted from the other radio base station performs control to receive the channel measurement result transmitted from the other radio base station.

[0355] <7> according to <5> The wireless base station,

[0356] In which, when the sending method information is information instructing the terminal device to send channel measurement results to all wireless base stations including the wireless base station, the control units of all wireless base stations including the wireless base station perform control to receive the channel measurement results sent from the terminal device.

[0357] <8> according to <1> to <7> The wireless base station described in any one of claims ,

[0358] In which, in a case where a channel measurement frame as a frame for channel measurement is sent to multiple terminal devices, after the channel measurement frame is sent from all wireless base stations including the wireless base station, the control unit performs control to send a return frame indicating a return method of the channel measurement result as a result of the channel measurement to the multiple terminal devices, and performs control to receive the channel measurement results sent from the multiple terminal devices through the return method indicated by the return frame.

[0359] <9> A wireless base station, comprising

[0360] A control unit that performs control to receive a start frame sent from other wireless base stations and instructs execution of channel measurement with a terminal device, and also performs control to send a channel measurement frame based on at least one of timing information or spatial information for sending a channel measurement frame, wherein the channel measurement frame is a frame for channel measurement described in the start frame.

[0361] <10> according to <9> The wireless base station,

[0362] In the case where the start frame includes timing information and space information for the wireless base station to transmit a channel measurement frame at the same timing as the timing at which the other wireless base stations transmit channel measurement frames,

[0363] The control unit performs control to transmit the frame for channel measurement at the same timing as that of the other wireless base stations based on timing information and space information for transmitting the frame for channel measurement.

[0364] <11> according to <9> The wireless base station,

[0365] In the case where the start frame includes timing information for the wireless base station to transmit a channel measurement frame at a timing different from the timing at which the other wireless base stations transmit channel measurement frames,

[0366] The control unit performs control to transmit a frame for channel measurement at a timing different from that of the other wireless base stations based on timing information for transmitting a frame for channel measurement.

[0367] <12> according to <9> to <11> The wireless base station described in any one of claims ,

[0368] wherein the start frame includes information indicating a sending method when the terminal device sends a channel measurement result as a result of the channel measurement to the wireless base station as sending method information, and the control unit performs control to receive the channel measurement result sent from the terminal device based on the sending method information.

[0369] <13> according to <12> The wireless base station,

[0370] Wherein, in the case where the sending method information is information instructing the terminal device to send a channel measurement result to any wireless base station including the wireless base station,

[0371] The control unit of the wireless base station to which the channel measurement results are sent from the terminal device performs control to receive the channel measurement results from the terminal device, and also performs control to send the received channel measurement results to the other wireless base stations, and the control unit of the wireless base station to which the channel measurement results are sent from the other wireless base stations performs control to receive the channel measurement results from the other wireless base stations.

[0372] <14> according to <12> The wireless base station,

[0373] Wherein, in the case where the sending method information is information instructing the terminal device to send channel measurement results to all wireless base stations including the wireless base station,

[0374] The control units of all the wireless base stations including the wireless base station perform control to receive channel measurement results from the terminal equipment.

[0375] <15> A terminal device comprising

[0376] a control unit that performs control to receive a start frame including, as transmission method information, information that is transmitted from a wireless base station and that indicates that channel measurement between the terminal device and the wireless base station is performed and also indicates a transmission method when a channel measurement result that is a result of the channel measurement is transmitted to the wireless base station,

[0377] performing control to receive a frame for channel measurement transmitted from the wireless base station based on the start frame to perform channel measurement, and

[0378] Control is performed to transmit the channel measurement result to the wireless base station based on the transmission method information.

[0379] <16> according to <15> The terminal device,

[0380] Here, in a case where the transmission method information is information indicating that the channel measurement result is to be transmitted to one of a plurality of wireless base stations, the control unit performs control to transmit the channel measurement result to the indicated wireless base station among the wireless base stations.

[0381] <17> according to <15> The terminal device,

[0382] Here, in a case where the transmission method information is information indicating that the channel measurement result is to be transmitted to all of the plurality of wireless base stations, the control unit performs control to transmit the channel measurement result to all of the plurality of wireless base stations.

[0383] <18> according to <15> The terminal device,

[0384] When a plurality of wireless base stations transmit channel measurement frames as frames used for the channel measurement at the same timing, the start frame includes timing information and space information for the plurality of wireless base stations to transmit the channel measurement frames at the same timing.

[0385] <19> according to <15> The terminal device,

[0386] When a plurality of wireless base stations do not transmit the channel measurement frames as frames used for the channel measurement at the same timing, the start frame includes timing information for the plurality of base stations to transmit the channel measurement frames at different timings.

[0387] <20> according to <15> to <19> A terminal device as described in any one of the above,

[0388] wherein, in a case where a frame for channel measurement as a frame used for the channel measurement is transmitted to a plurality of terminal devices, after the frame for channel measurement is transmitted from all wireless base stations, a return frame indicating a method of returning a channel measurement result is transmitted from the wireless base station that has transmitted the start frame to the plurality of terminal devices, and

[0389] The control unit performs control to receive the return frame, and also performs control to transmit the channel measurement result to at least any one of all the wireless base stations by the return method indicated by the received return frame.

[0390] Label list

[0391] 11.11-1,11-2 Wireless base station

[0392] 12. 12-1 to 12-4 Terminal equipment

[0393] 31 Control unit

[0394] 32 Power supply unit

[0395] 33 Communication unit

[0396] 34, 34-1 to 34-n antenna

[0397] 51 Wireless Control Unit

[0398] 52 Data processing unit

[0399] 53 Modulation and demodulation unit

[0400] 54 Spatial Signal Processing Unit

[0401] 55, 55-1, 55-n wireless interface unit

[0402] 56, 56-1 to 56-n amplifier units

[0403] 57 Channel Estimation Unit

[0404] 71 Control unit

[0405] 72 Power Supply

[0406] 73 Communication unit

[0407] 74, 74-1 to 74-m antennas

[0408] 91 Wireless Control Unit

[0409] 92 Data Processing Unit

[0410] 93 Modulation and demodulation unit

[0411] 94 Spatial Signal Processing Unit

[0412] 95, 95-1 to 95-n wireless interface units

[0413] 96, 96-1 to 96-n Amplifier Units

[0414] 97 Channel Estimation Unit

Claims

1. A wireless base station, comprising A control unit performs control to transmit a start frame instructing other wireless base stations to perform channel measurement when performing channel measurement with a terminal device.

2. The wireless base station according to claim 1, in, The start frame includes: identification information of the other wireless base station; and at least one of timing information or space information for the other wireless base station to send a frame for channel measurement, wherein the frame for channel measurement is a frame used for channel measurement.

3. The wireless base station according to claim 2, in, When the wireless base station and the other wireless base stations transmit channel measurement frames at the same timing, the start frame includes timing information and space information for the other wireless base stations to transmit channel measurement frames at the same timing as the wireless base station transmits the channel measurement frames.

4. The wireless base station according to claim 2, in, When the wireless base station and the other wireless base station do not transmit the channel measurement frame at the same timing, the start frame includes timing information for the other wireless base station to transmit the channel measurement frame at a timing different from the timing at which the wireless base station transmits the channel measurement frame.

5. The wireless base station according to claim 1, in, The start frame includes, as transmission method information, information indicating a transmission method when the terminal device transmits a channel measurement result as a result of the channel measurement to the wireless base station, and The control unit performs control to receive a channel measurement result transmitted from the terminal device based on the transmission method information.

6. The wireless base station according to claim 5, in, In a case where the transmission method information is information instructing the terminal device to transmit a channel measurement result to any wireless base station including the wireless base station, The control unit of the wireless base station to which the channel measurement result is transmitted from the terminal device performs control to receive the channel measurement result from the terminal device and also transmits the received channel measurement result to the other wireless base stations, and The control unit of the radio base station to which the channel measurement result is transmitted from the other radio base station performs control to receive the channel measurement result transmitted from the other radio base station.

7. The wireless base station according to claim 5, in, In the case where the transmission method information is information instructing the terminal device to transmit channel measurement results to all wireless base stations including the wireless base station, control units of all wireless base stations including the wireless base station perform control to receive the channel measurement results transmitted from the terminal device.

8. The wireless base station according to claim 1, in, In a case where a frame for channel measurement as a frame for channel measurement is transmitted to a plurality of terminal devices, after the frame for channel measurement is transmitted from all wireless base stations including the wireless base station, the control unit performs control to transmit a return frame indicating a method of returning a channel measurement result as a result of the channel measurement to the plurality of terminal devices, and Control is performed to receive channel measurement results transmitted from the plurality of terminal devices by a return method indicated by the return frame.

9. A wireless base station, comprising A control unit that performs control to receive a start frame sent from other wireless base stations and instructs execution of channel measurement with a terminal device, and also performs control to send a channel measurement frame based on at least one of timing information or spatial information for sending a channel measurement frame, wherein the channel measurement frame is a frame for channel measurement described in the start frame.

10. The wireless base station according to claim 9, in, In a case where the start frame includes timing information and space information for the wireless base station to transmit a channel measurement frame at the same timing as the timing at which the other wireless base stations transmit channel measurement frames, The control unit performs control to transmit the frame for channel measurement at the same timing as that of the other wireless base stations based on timing information and space information for transmitting the frame for channel measurement.

11. The wireless base station according to claim 9, in, When the start frame includes timing information for the wireless base station to transmit a channel measurement frame at a timing different from the timing at which the other wireless base stations transmit channel measurement frames, The control unit performs control to transmit a frame for channel measurement at a timing different from that of the other wireless base stations based on timing information for transmitting a frame for channel measurement.

12. The wireless base station according to claim 9, in, The start frame includes, as transmission method information, information indicating a transmission method when the terminal device transmits a channel measurement result as a result of the channel measurement to the wireless base station, and The control unit performs control to receive a channel measurement result transmitted from the terminal device based on the transmission method information.

13. The wireless base station according to claim 12, in, In a case where the transmission method information is information instructing the terminal device to transmit a channel measurement result to any wireless base station including the wireless base station, The control unit of the wireless base station to which the channel measurement result is transmitted from the terminal device performs control to receive the channel measurement result from the terminal device, and also performs control to transmit the received channel measurement result to the other wireless base stations, and The control unit of the wireless base station to which the channel measurement result is transmitted from the other wireless base station performs control to receive the channel measurement result from the other wireless base station.

14. The wireless base station according to claim 12, in, In a case where the transmission method information is information instructing the terminal device to transmit channel measurement results to all wireless base stations including the wireless base station, The control units of all the wireless base stations including the wireless base station perform control to receive channel measurement results from the terminal equipment.

15. A terminal device comprising a control unit that performs control to receive a start frame including, as transmission method information, information that is transmitted from a wireless base station and that indicates that channel measurement between the terminal device and the wireless base station is performed and also indicates a transmission method when a channel measurement result that is a result of the channel measurement is transmitted to the wireless base station, performing control to receive a frame for channel measurement transmitted from the wireless base station based on the start frame to perform channel measurement, and Control is performed to transmit the channel measurement result to the wireless base station based on the transmission method information.

16. The terminal device according to claim 15, in, In a case where the transmission method information is information indicating that the channel measurement result is to be transmitted to one of a plurality of wireless base stations, the control unit performs control to transmit the channel measurement result to the indicated wireless base station among the wireless base stations.

17. The terminal device according to claim 15, in, In a case where the transmission method information is information indicating that the channel measurement result is to be transmitted to all of the plurality of wireless base stations, the control unit performs control to transmit the channel measurement result to all of the plurality of wireless base stations.

18. The terminal device according to claim 15, in, When a plurality of wireless base stations transmit the channel measurement frames as frames used for the channel measurement at the same timing, the start frame includes timing information and space information for the plurality of wireless base stations to transmit the channel measurement frames at the same timing.

19. The terminal device according to claim 15, in, When a plurality of wireless base stations do not transmit the channel measurement frames as frames used for the channel measurement at the same timing, the start frame includes timing information for causing the plurality of base stations to transmit the channel measurement frames at different timings.

20. The terminal device according to claim 15, in, In a case where a frame for channel measurement as a frame for the channel measurement is transmitted to a plurality of terminal devices, after the frame for channel measurement is transmitted from all wireless base stations, a return frame indicating a method of returning a channel measurement result is transmitted from the wireless base station that has transmitted the start frame to the plurality of terminal devices, and The control unit performs control to receive the return frame, and also performs control to transmit the channel measurement result to at least any one of all the wireless base stations by the return method indicated by the received return frame.

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