ACCESS POINT, TERMINAL EQUIPMENT, AND COMMUNICATION METHOD

Abstract

The invention relates to an access point provided with a control circuit which, on the basis of information relating to transmission power control received from another access point, generates parameters relating to uplink transmission power control and a transmission circuit which transmits control signals including the aforementioned parameters.

Description

Access point, terminal, and communication method

[0001] The present disclosure relates to an access point, a terminal, and a communication method.

[0002] The Institute of Electrical and Electronics Engineers (IEEE) is currently developing the technical specifications for IEEE 802.11be (hereinafter referred to as "11be") as the successor standard to IEEE 802.11ax (hereinafter referred to as "11ax"), the 802.11 standard.

[0003] In 11be, Multi-AP (MAP) coordination (also called "cooperative communication") is being considered, which involves cooperative transmission and reception of data between multiple access points (also called "base stations", hereinafter referred to as "APs (Access Points)") and multiple terminals (hereinafter referred to as "STAs (Stations)") in the downlink and uplink (see, for example, Non-Patent Documents 1, 2 or 3).

[0004] IEEE 802.11-19 / 1903r0, Uplink Coordinated Multi-APIEEE 802.11-20 / 0056r0, Preparations for Coordinated OFDMAIEEE 802.11-20 / 0617r0, Multi-AP Operation -Basic DefinitionIEEE P802.11ax / D6.0, November 2019IEEE 802.11-19 / 1582r2, Coordinated AP Time / Frequency Sharing in a Transmit Opportunity in 11beIEEE 802.11-19 / 1961r1, Multi-AP Group Establishment,2020-01-02IEEE 802.11-19 / 1972r1, Operation of Virtual BSS for Multi-AP Coordination,2019-11-05

[0005] However, methods for controlling transmission power in wireless communications such as wireless local area networks (WLANs) have not been fully studied.

[0006] Non-limiting examples of the present disclosure contribute to providing an access point, a terminal, and a communication method that can flexibly control uplink transmission power for each terminal.

[0007] An access point according to one embodiment of the present disclosure includes a control circuit that generates parameters related to uplink transmission power control based on information related to transmission power control received from other access points, and a transmission circuit that transmits a control signal including the parameters.

[0008] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

[0009] According to an embodiment of the present disclosure, uplink transmission power for each terminal can be flexibly controlled.

[0010] Further advantages and benefits of one embodiment of the present disclosure will become apparent from the specification and drawings. Such advantages and / or benefits may be provided by some embodiments and features described in the specification and drawings, respectively, but not necessarily all of them may be provided to obtain one or more identical features.

[0011] FIG. 1 is a diagram showing an example of a procedure for cooperative communication. FIG. 1 shows an example of a format of a Common Info field. FIG. 1 shows an example of a format of a User Info field. FIG. 1 shows an example of a target received signal strength indicator (RSSI). FIG. 1 shows an example of a Trigger type. FIG. 1 shows an example of uplink multi-AP coordination. FIG. 1 shows an example of a coordinated AP (CAP) transmission (Tx) phase. FIG. 2 shows an example of a configuration of a wireless communication system and an example of resource allocation. Block diagram showing an example of a configuration of a part of an AP. Block diagram showing an example of a configuration of a part of an STA. Block diagram showing an example of a configuration of an AP. Block diagram showing an example of a configuration of an STA. Sequence diagram showing an example of uplink cooperative communication processing. FIG. 2 shows an example of resource allocation. FIG. 1 shows an example of a Common Info field and a User Info field according to Example 3. FIG. 2 shows an example of a User Info field according to Example 4. FIG. 3 shows an example of a target RSSI format. FIG. 4 shows an example of a trigger frame configuration. FIG. 5 shows an example of a trigger frame configuration. FIG. 6 shows an example of resource allocation.

[0012] Hereinafter, each embodiment of the present disclosure will be described in detail with reference to the drawings.

[0013] (First embodiment) [MAP coordination] FIG. 1 is a diagram showing an example of the operation of MAP coordination.

[0014] As shown in FIG. 1, in MAP coordination, for example, when cooperative communication is started, it is considered to perform control of the following three steps (see, for example, Non-Patent Document 3).

[0015] The first step is, for example, a step (or section) of determining APs that will perform cooperative control (also called "Multi-AP setup" or "MAP selection"). In this step, for example, APs may communicate information about the capabilities of each AP or the STAs they accommodate to select the APs that will cooperate.

[0016] The second step is, for example, a step (or section) in which information regarding data to be transmitted and received through cooperative communication (e.g., transmission method or Modulation and Coding Scheme (MCS)) is communicated between APs (also called "Multi-AP coordination").

[0017] The third step is, for example, a step (or section) of transmitting and receiving sounding or data for cooperative communication between the AP and the STA (for example, also called "Multi-AP transmission").

[0018] For example, 11ax supports multi-user (MU) transmission in the uplink (UL). UL MU transmission includes, for example, MU-Multiple Input Multiple Output (MU-MIMO) and Orthogonal Frequency Division Multiple Access (OFDMA). In UL MU transmission, for example, an AP may transmit a signal (also referred to as a "Trigger frame") that triggers an uplink signal to multiple STAs it accommodates. A terminal may transmit an uplink signal (also referred to as an uplink response signal) to the AP based on the Trigger frame. The uplink response signal is also referred to as a Trigger-based Physical layer convergence procedure Protocol Data Unit (TB PPDU), for example.

[0019] When transmitting an uplink response signal, for example, uplink transmission power control may be applied in the STA. pwr STA ") may be calculated according to the following formulas (1) and (2) using, for example, the setting value of the "AP TX Power" field related to the transmission power of the AP in the downlink (DL) included in the Common Info field in the Trigger frame shown in FIG. 2 and the setting value of the "UL Target RSSI" field related to the target RSSI (e.g., target received signal strength) of the AP in the uplink (UL) included in the User Info field in the Trigger frame shown in FIG. 3 (see, for example, Non-Patent Document 3).

[0020] The Common Info field may include, for example, information common to multiple STAs (e.g., also referred to as "common information" or "STA common information"). The User Info field may include, for example, individual information for each STA (e.g., referred to as "user information," "STA individual information," or "user individual information").

[0021] In formula (1) and formula (2), PL DL represents the path loss in the downlink, and Tx pwr AP represents the setting value of the AP TX Power field, and RSSI represents the received strength (e.g., RSSI) of the downlink signal estimated (or measured) at the STA, and Target RSSI represents the setting value of the UL Target RSSI field.

[0022] In addition, Target RSSI (e.g., Target RSSI ) can be set to, for example, the values ​​shown in FIG.

[0023] Furthermore, for the Trigger frame, multiple types (e.g., called "Trigger type") may be defined, for example, as shown in Fig. 5. For example, depending on the value of the Trigger type, the contents notified in the "Trigger Dependent Common Info" field included in the Common Info field and the "Trigger Dependent User Info" field included in the User Info field may differ (for example, see Non-Patent Document 4).

[0024] In 11be, when cooperative communication is performed for an uplink response signal, for example, as shown in Fig. 6, multiple APs (e.g., AP-1 and AP-2) transmit trigger frames (e.g., represented as UL MU Trigger) with the same content at the same timing, and a STA that is requested to send an uplink response signal may transmit an uplink response signal (e.g., represented as High Efficiency (HE) TB PPDU) after receiving the trigger frame (see, for example, Non-Patent Document 1). Note that, as shown in Fig. 6, trigger frames include, for example, a trigger frame used in communication between APs (also referred to as, for example, a MAP trigger frame or an M-AP Trigger), and a trigger frame used in communication between an AP and a STA (e.g., a UL MU Trigger).

[0025] The uplink transmission power control of 11ax is performed based on, for example, one setting value "AP TX Power" (in other words, the downlink transmission power of one AP) included in the Common Info field of the Trigger frame. However, for example, in MAP coordination, there is a possibility that uplink response signals are received from multiple APs, so with one setting value as in 11ax, the accuracy of uplink transmission power control for each of the multiple APs may be reduced.

[0026] For example, if the downlink transmission power differs between multiple APs performing cooperative communication, as shown in equation (1), a single setting value for the downlink transmission power (AP TX Power) may result in a decrease in the accuracy of the path loss estimation between the AP and the STA, which is estimated from the downlink signal from each AP.

[0027] Furthermore, compared to cellular communication, for example, in a wireless LAN such as Wi-Fi (registered trademark), it is expected that APs may be arranged irregularly or that performance variations between APs may be large. Therefore, it is expected that there are more cases where the transmission power between APs varies than in cellular communication. For this reason, when uplink MAP coordination processing is performed in wireless communication using a wireless LAN, the accuracy of uplink transmission power control similar to that of the above-mentioned 11ax is likely to be reduced.

[0028] Therefore, in one embodiment of the present disclosure, for example, a method for improving the accuracy of transmission power control of an uplink signal (for example, an uplink response signal) in uplink MAP coordination processing will be described.

[0029] In the following, for example, a period during which information is exchanged between APs before an AP transmits a MAP trigger is referred to as the "Negotiation phase." Furthermore, for example, a period during which data is transmitted from an AP to a STA after the Negotiation phase is referred to as the "Multi-AP transmission phase." The Negotiation phase may be, for example, the Multi-AP coordination period of Non-Patent Document 3, or a period including both Multi-AP setup and Multi-AP coordination. The Negotiation phase may also include a period during which control information such as beacons is communicated between APs. Furthermore, for example, the Negotiation phase may include a period (Schedule Allocation) during which each AP instructs the allocation of resources (frequency or time (TXOP: transmission opportunity)) as described in Non-Patent Document 5 (e.g., FIG. 7).

[0030] In the following description, a set of APs performing MAP coordination (e.g., cooperative communication) is referred to as an "AP group." The AP group may be, for example, a Static Multi-AP Group or a Dynamic Multi-AP Group (see, for example, Non-Patent Document 6), or a Virtual BSS (see, for example, Non-Patent Document 7). In an AP group, an AP that controls Multi-AP coordination may be referred to as a "Sharing AP" (or a "Coordinator AP" or a "first AP"). An AP whose Multi-AP coordination is controlled by a Sharing AP may be referred to as a "Shared AP" (or a "Coordinated AP" or a "second AP"). In an AP group, a Sharing AP may start transmission using, for example, Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA).

[0031] [Configuration of Wireless Communication System] The wireless communication system according to this embodiment may include, for example, a plurality of APs 100 and a plurality of STAs 200.

[0032] For example, in this embodiment, the AP 100 may notify the STAs 200 of information regarding the transmission power of the AP, taking into consideration the cooperative communication control for each STA 200, by using a trigger frame. The word "notification" may be interpreted as "transmission" or "instruction."

[0033] The information about the transmission power of the AP may include, for example, information about the downlink transmission power of the AP 100 that communicates with each of the multiple STAs 200 that are communication control targets among the multiple APs 100. For example, the STA 200 that does not perform cooperative communication may be notified of information about the transmission power of the AP 100 to which the STA 200 is connected (e.g., referred to as an association AP).

[0034] Furthermore, for example, the STA 200 performing cooperative communication may be notified of information regarding the transmission power of the AP 100 according to the cooperative communication control. For example, when the control method of cooperative communication (also referred to as "cooperative communication mode") is diversity reception, the STA 200 performing cooperative communication may be notified of information regarding the transmission power of one AP 100 that is scheduled to receive the uplink signal. Furthermore, for example, when the cooperative communication mode is joint reception, the STA 200 performing cooperative communication may be notified of information regarding the combined value of the transmission power of multiple APs 100 that are scheduled to receive the uplink signal.

[0035] Fig. 8 is a diagram illustrating an example of the configuration of a wireless communication system according to this embodiment. Fig. 8 illustrates an example in which AP1 and AP2 perform communication control for STA1, STA2, and STA3. As illustrated in Fig. 8, STA1 and STA3 do not perform cooperative communication, while STA2 performs cooperative communication (e.g., joint reception). In the case of resource allocation illustrated in Fig. 8, for example, in a trigger frame, STA1 may be notified of information regarding the transmission power of AP1, STA2 may be notified of information regarding a combined value of the transmission power of AP1 and the transmission power of AP2, and STA3 may be notified of information regarding the transmission power of AP2.

[0036] An example of notification of information regarding the transmission power (for example, downlink transmission power) of the AP 100 to each STA 200 in the trigger frame will be described later.

[0037] By notifying information related to the transmission power of the AP 100 by such a trigger frame, each STA 200 can control the transmission power according to the transmission method of the uplink signal (e.g., whether or not cooperative communication is performed). Therefore, for example, by improving the accuracy of the transmission power control of the uplink signal in the MAP coordination process, it is possible to improve the uplink throughput.

[0038] An example of the configuration of the AP 100 and the STA 200 according to this embodiment will be described below.

[0039] 9 is a block diagram illustrating a configuration example of a portion of an AP 100 according to an embodiment of the present disclosure. In the AP 100 illustrated in FIG. 9, a control unit (e.g., corresponding to a control circuit) generates parameters related to uplink transmission power control for each of multiple uplinks in uplink communication control (e.g., multi-AP control) based on communication between base stations, and a transmission unit (e.g., corresponding to a transmission circuit) transmits a control signal (e.g., a trigger frame) including the parameters.

[0040] Fig. 10 is a block diagram illustrating a configuration example of a portion of an STA 200 according to an embodiment of the present disclosure. In the STA 200 illustrated in Fig. 10, a receiver (e.g., a receiver circuit) receives a control signal including parameters related to uplink transmission power control for each of multiple uplinks in uplink communication control (e.g., multi-AP control) based on communication between base stations, and a controller (e.g., a control circuit) controls the uplink transmission power based on the parameters.

[0041] [Configuration example of AP 100] Fig. 11 is a block diagram showing a configuration example of AP 100. AP 100 shown in Fig. 11 may include, for example, a setting unit 101, a STA-directed control signal generating unit 102, an AP-directed control signal generating unit 103, a transmission signal generating unit 104, a wireless transmission / reception unit 105, and a received signal demodulation / decoding unit 106.

[0042] For example, the control unit shown in Fig. 9 may correspond to the processing units related to generation of transmission signals in Fig. 11 (e.g., setting unit 101, STA-directed control signal generating unit 102, AP-directed control signal generating unit 103, transmission signal generating unit 104, and received signal demodulation and decoding unit 106, etc.). Also, the wireless transmission unit shown in Fig. 9 may correspond to, for example, the wireless transmission / reception unit 105 shown in Fig. 11.

[0043] Also, for example, the setting unit 101, the STA control signal generating unit 102, and the AP control signal generating unit 103 may be included in an access control unit (e.g., a Medium Access Control (MAC) processing unit), and the transmission signal generating unit 104 and the received signal demodulation / decoding unit 106 may be included in a baseband (BB) processing unit.

[0044] The setting unit 101 may, for example, set control information for the STAs 200. For example, the setting unit 101 may set resource allocation information and scheduling information such as MCS for each STA 200. Furthermore, the setting unit 101 may determine parameters related to uplink transmission power control (hereinafter referred to as uplink transmission power control parameters), such as AP TX Power or target RSSI, based on information input from the received signal demodulation and decoding unit 106 (for example, control information notified by communication between AP groups in the negotiation phase). The setting unit 101 may, for example, output control information including the uplink transmission power control parameters to the STA-directed control signal generation unit 102.

[0045] Furthermore, the setting unit 101 may determine, for example, a transmission power control parameter to be notified through communication between AP groups in the negotiation phase based on scheduling information, and may output control information including the determined transmission power control parameter to the AP-directed control signal generation unit 103.

[0046] Note that during the negotiation phase, for example, the scheduler may not have completed final resource allocation. Therefore, the transmission power control parameters notified by each AP 100 during the negotiation phase may be, for example, parameters related to candidate transmission powers applicable to the AP 100 depending on the capability or coverage of each AP 100. The setting unit 101 may output, for example, parameters related to candidate transmission powers applicable to the AP 100 to the AP-directed control signal generating unit 103.

[0047] For example, each AP 100 may notify a transmission power control parameter based on its capability or coverage, allowing the sharing AP to recognize the transmission power of each AP 100 before the scheduler makes a final resource allocation. The transmission power control parameter may include, for example, the transmission power capability of each AP 100. The transmission power capability may include, for example, the range of transmission power that each AP 100 can output (e.g., the maximum value, minimum value, and step width of the transmission power of the AP 100). The transmission power control parameter may also include, for example, the transmission power capability of the STAs 200 accommodated by each AP 100.

[0048] The sharing AP may reset the transmission power of each AP 100 based on, for example, transmission power control parameters notified from each AP 100 in the AP group. For example, the sharing AP may reset the transmission power of each AP 100 based on the transmission power capability of the AP 100 or the STA 200. A method for resetting the transmission power may be, for example, to unify the transmission power of multiple APs 100 included in the AP group if the difference in the transmission power capabilities of each AP 100 is within a threshold. The unified transmission power may be set to, for example, the transmission power of one AP among the transmission powers exchanged between the APs 100 (e.g., the maximum or minimum transmission power in the AP group). Alternatively, the unified transmission power may be set to, for example, the average or total transmission power of the multiple APs 100 in the AP group. By unifying the transmission power, for example, the sharing AP does not need to notify each AP 100 of the reset transmission power, but can simply notify the existing TX AP Power, thereby reducing signaling overhead.

[0049] Furthermore, the information regarding the transmission power capability may be, for example, control information such as the "UL MU Power Capabilities element" applied in 11ax. Furthermore, the transmission power control parameters notified between APs 100 may include, for example, an OMI (Operating Mode Indication) that notifies the applicable bandwidth or the number of SSs (spatial streams). Furthermore, the transmission power control parameters notified between APs 100 may include, for example, a path loss. For example, the sharing AP may determine whether to apply cooperative communication based on the path loss notified from each AP 100.

[0050] Furthermore, the transmission power control parameters notified between APs 100 may include, for example, spatial reuse (parameterized spatial reuse (PSR)) to be notified to the STA 200 in the Common Info field of the Trigger frame. The sharing AP may set the transmission power of each AP 100 and the target RSSI of the STA 200, for example, based on the PSR notified from each AP 100. For example, when uplink cooperative communication is applied, the sharing AP may reset the target RSSI of each AP 100 in the negotiation phase, taking into account the combined gain. An example of a method for resetting the target RSSI when uplink cooperative communication is applied will be described later.

[0051] 11 , the STA-directed control signal generating unit 102 may generate, for example, a control signal (e.g., a trigger frame) for the STA 200. For example, the STA-directed control signal generating unit 102 may generate the control signal based on control information (e.g., a result of resource allocation to each STA 200, or transmission power control parameters such as AP Tx Power and target RSSI) input from the setting unit 101 and information input from the received signal demodulation and decoding unit 106.

[0052] The control signal for STA200 may include, for example, time and frequency resource information (e.g., resource unit (RU) allocation information for uplink cooperative communication, TXOP, LENGTH, etc.), as well as at least one of transmission power control parameters (e.g., transmission power of AP100 or target RSSI, etc.), information regarding trigger frame generation (e.g., UL MCS, guard interval (GI), long training field (LTF) mode), a trigger type that notifies the type of control signal, and terminal identification information (e.g., association ID (AID)).

[0053] In addition, in this embodiment, for example, the control signal for the STA 200 may include information regarding the downlink transmission power for each STA 200 based on the cooperative communication mode by the AP 100 applied to the STA 200.

[0054] The STA-directed control signal generating unit 102 outputs the generated control signal to the transmission signal generating unit 104, for example.

[0055] An example of the format of a control signal directed to STA 200 during uplink cooperative communication will be described later.

[0056] Furthermore, for example, there may be cases where at least some of the multiple STAs 200 instructed by the Trigger frame to transmit uplink response signals do not perform uplink cooperative communication. Therefore, if a control signal format for the STAs 200 during uplink cooperative communication is applied, signaling overhead may increase. For example, if each of the multiple STAs 200 instructed by the Trigger frame to transmit uplink response signals does not perform uplink cooperative communication, it is not necessary to notify transmission power control parameters that take into account the control method used in cooperative communication. Therefore, the AP 100 may, for example, determine whether to apply a control signal format for the STAs 200 during uplink cooperative communication when generating a control signal (in other words, may switch the format of the control signal). Examples of methods for switching the control signal format will be described later.

[0057] The AP-directed control signal generating unit 103 may generate, for example, a control signal (e.g., a trigger frame) for the AP 100. For example, the AP-directed control signal generating unit 103 may generate the control signal based on control information (e.g., a transmission power control parameter) input from the setting unit 101 and information input from the received signal demodulation and decoding unit 106.

[0058] The control signal for the AP 100 may include, for example, time and frequency resource information (e.g., RU allocation information for uplink cooperative communication, TXOP, LENGTH, etc.), as well as at least one of a transmission power control parameter (e.g., the transmission power of the AP 100 or the target RSSI, etc.) and information related to the generation of a control signal (e.g., a trigger frame) for the STA 200 (e.g., UL MCS, GI, LTF mode). Furthermore, the control signal for the AP 100 may include, for example, at least one of the transmission power capability of each AP 100 (e.g., the range of transmission power that each AP 100 can output (e.g., the maximum, minimum, and step width of the transmission power)) and the transmission power capability of the STA 200 accommodated in each AP 100.

[0059] The AP-directed control signal generating unit 103 outputs the generated control signal to the transmission signal generating unit 104, for example.

[0060] The transmission signal generation unit 104 performs coding and modulation processing on, for example, a control signal, or data and ACK / Block-ACK, input from the STA-directed control signal generation unit 102 or the AP-directed control signal generation unit 103. The transmission signal generation unit 104 may generate a radio frame (transmission signal) by, for example, adding a pilot signal used for frequency synchronization or timing synchronization on the receiving side (e.g., another AP 100 or STA 200), a channel estimation signal (e.g., LTF or Extremely High Throughput (EHT)-LTF), etc. to the modulated signal. The transmission signal generation unit 104 outputs the generated transmission signal to the radio transmission / reception unit 105.

[0061] The radio transmission / reception unit 105 performs radio transmission processing such as D / A conversion and up-conversion to a carrier frequency on the transmission signal input from the transmission signal generation unit, and transmits the signal after radio transmission processing via an antenna.

[0062] For example, when AP 100 receives an uplink signal (e.g., an uplink response signal (TB-PPDU)) and feedback information transmitted from STA 200, or a control signal between AP groups, AP 100 may operate as follows.

[0063] A radio signal received via an antenna is input to the radio transmission / reception unit 105. The radio transmission / reception unit 105 performs radio reception processing, such as down-conversion of the carrier frequency, on the received radio signal, and outputs the signal after the radio reception processing to the received signal demodulation / decoding unit 106.

[0064] The received signal demodulation and decoding unit 106 may, for example, perform processing such as autocorrelation processing on the signal input from the wireless transceiver unit 105 and extract the received wireless frame. The received signal demodulation and decoding unit 106 may also decode and demodulate, for example, an uplink response signal (e.g., TB-PPDU) and feedback information from the STA 200, or a control signal between AP groups, which are included in the extracted wireless frame. The received signal demodulation and decoding unit 106 may, for example, output the feedback information and the control signal between AP groups to the setting unit 101, the STA-directed control signal generation unit 102, and the AP-directed control signal generation unit 103.

[0065] [Configuration Example of STA 200] Fig. 12 is a block diagram showing a configuration example of STA 200 according to this embodiment. STA 200 shown in Fig. 12 may include, for example, a radio transceiver 201, a received signal demodulation and decoding unit 202, a transmission power calculation unit 203, a response signal generation unit 204, and a transmission signal generation unit 205.

[0066] For example, the control unit shown in Fig. 10 may correspond to the processing units related to generation of the transmission signal in Fig. 12 (e.g., the received signal demodulation and decoding unit 202, the transmission power calculation unit 203, the response signal generation unit 204, and the transmission signal generation unit 205, etc.). Also, the wireless receiving unit shown in Fig. 10 may correspond to the wireless transmitting and receiving unit 201 shown in Fig. 12, for example.

[0067] Also, for example, the transmission power calculation unit 203 and the response signal generation unit 204 may be included in the access control unit, and the received signal demodulation and decoding unit 202 and the transmission signal generation unit 205 may be included in the baseband processing unit.

[0068] For example, the wireless transmission / reception unit 201 receives a signal transmitted from the AP 100 via an antenna, performs wireless reception processing such as down-conversion and A / D conversion on the received signal, and outputs the signal after the wireless reception processing to the received signal demodulation / decoding unit 202. The wireless transmission / reception unit 201 may also perform wireless transmission processing such as D / A conversion and up-conversion to a carrier frequency on a signal input from the transmission signal generation unit 205. The wireless transmission / reception unit 201 may also transmit the signal after the wireless transmission processing via the antenna based on the transmission power instructed by the transmission power calculation unit 203, for example.

[0069] The received signal demodulation and decoding unit 202 may, for example, perform processing such as autocorrelation processing on the signal input from the wireless transceiver unit 201 and extract a received wireless frame. The received signal demodulation and decoding unit 202 may, for example, demodulate and decode a control signal (e.g., a trigger frame) included in the extracted wireless frame and output a transmission power control parameter such as AP TX Power or target RSSI to the transmission power calculation unit 203. The received signal demodulation and decoding unit 202 may also output control parameters such as time and frequency resource information (e.g., RU allocation information, TXOP, LENGTH, etc.) or MCS to the transmission signal generation unit 205.

[0070] The received signal demodulation and decoding unit 202 may determine whether or not the control signal format for the STA 200 during uplink cooperative communication is to be applied, for example, based on a control signal format switching control method described later.

[0071] The transmission power calculation unit 203 may calculate, for example, the transmission power of an uplink signal (e.g., an uplink response signal). For example, the transmission power calculation unit 203 may calculate the transmission power of the uplink response signal based on transmission power control parameters (e.g., AP TX Power and target RSSI) input from the received signal demodulation and decoding unit 202 and a path loss (not shown) estimated from the downlink signal. The transmission power calculation unit 203 may output, for example, information related to the calculated transmission power to the wireless transmission and reception unit 201. An example of a method for calculating the uplink transmission power in the transmission power calculation unit 203 will be described later. The word "calculate" may be read as "determine." For example, the transmission power may be determined based on information in a table format.

[0072] The response signal generating unit 204 may, for example, generate an uplink response signal and output the generated uplink response signal to the transmission signal generating unit 205. The uplink response signal may include, for example, the ID of the STA 200 and transmission information of the STA 200 (for example, data, a transmission buffer status notification, or a DL Data request).

[0073] The transmission signal generation unit 205 encodes and modulates the uplink response signal input from the response signal generation unit 204, for example, based on control parameters (e.g., MCS, etc.) input from the received signal demodulation and decoding unit 202. The transmission signal generation unit 205 may, for example, add a control signal (preamble) such as a pilot signal used for frequency synchronization or timing synchronization on the receiving side (e.g., AP 100), a channel estimation signal, etc. to the modulated signal, and generate a radio frame (transmission signal). The transmission signal generation unit 205 outputs the generated transmission signal to the radio transmission and reception unit 201, for example.

[0074] [Example of Operation of AP and STA] Next, an example of operation of the AP 100 and the STA 200 according to this embodiment will be described.

[0075] FIG. 13 is a sequence diagram showing an example of the operation of the AP 100 and the STA 200 according to this embodiment.

[0076] 13, as an example, the operation of two APs 100 (e.g., AP1 and AP2) and two STAs 200 (e.g., STA1 and STA2) will be described. Also, in FIG. 13, for example, AP1 is a sharing AP and AP2 is a shared AP.

[0077] In FIG. 13, in the negotiation phase, AP1 and AP2 may notify, for example, time and frequency resource information (e.g., RU allocation information for uplink cooperative communication, TXOP, LENGTH, etc.), transmission power control parameters (e.g., transmission power of each AP100, target RSSI, etc.), or information regarding trigger frame generation (e.g., UL MCS, GI, or LTF mode).

[0078] The transmission power control parameters in the negotiation phase may include, for example, the transmission power capability of each AP 100 (for example, the range of transmission power that each AP 100 can output (for example, the maximum, minimum, and step width of transmission power)). Also, the transmission power control parameters may include, for example, the transmission power capability of the STA 200 accommodated in each AP 100. Based on the transmission power capabilities of each AP 100 and STA 200, for example, the AP 100 can perform cooperative control and scheduling that takes capabilities into consideration.

[0079] Furthermore, in the negotiation phase, for example, after the sharing AP collects the transmission power control parameters (e.g., transmission power capability) of each shared AP, there may be cases where the transmission power control parameters (e.g., transmission power, target RSSI, capability of AP 100) notified from other APs 100 do not fall within a specified range (e.g., X ≧ transmission power control parameter ≧ Y). In this case, the sharing AP may exclude the corresponding AP 100 from the APs (e.g., AP group) performing cooperative communication.

[0080] The range setting values ​​X and Y may be set based on, for example, the transmission power, target RSSI, and capability of the sharing AP. For example, if the transmission power control parameter is the transmission power of AP 100, X may be set to (transmission power of sharing AP) + α, and Y may be set to (transmission power of sharing AP) - α. α may be, for example, an integer or a real number.

[0081] For example, the greater the difference in transmission power, target RSSI, or capability between APs 100 in an AP group, the more complex the control of cooperative communication becomes. Therefore, the sharing AP can easily control cooperative communication by excluding APs with large differences in transmission power control parameter values ​​between them (e.g., APs 100 whose transmission power control parameter does not fall within the range of X ≧ transmission power control parameter ≧ Y) from the APs that perform cooperative communication.

[0082] Note that part of the above information may be notified by, for example, a MAP trigger.

[0083] As shown in FIG. 13, when the negotiation phase ends, the sharing AP (for example, AP1) may transmit a multi-AP trigger frame to each AP 100 (for example, AP2) that is performing cooperative communication.

[0084] For example, after a specified time (e.g., Short Inter Frame Space (SIFS)) has elapsed since the transmission and reception of the Multi-AP trigger frame, the APs 100 (e.g., AP1 and AP2) in the AP group may simultaneously transmit a trigger frame (e.g., a trigger frame for TB-PPDU) for triggering uplink communication of the STAs 200 (e.g., STA1 and STA2). Note that the information included in the PPDU containing this trigger frame may be the same information between the APs 100, for example. For example, by multiple APs 100 transmitting the same (common) information in the trigger frame, the STAs 200 can receive signals from each AP 100 while suppressing interference.

[0085] For example, in a PPDU including a Trigger frame, values ​​such as a Cyclic shift set for each antenna or stream may be set to different values ​​for each AP 100. Also, a portion of the preamble included in the PPDU may be replaced for each AP 100. Also, the frequency resource of the EHT-LTF may be different for each AP 100. Also, the preamble may be, for example, a signal in units of a sub-channel (for example, a 20 MHz band), and even if the data is a signal in a frequency band that is part of the preamble, the preamble may be a signal in the frequency band of the sub-channel (for example, a 20 MHz band).

[0086] For example, as shown in Fig. 13, after receiving a Trigger frame, STA200 (e.g., STA1 and STA2) may check whether an AID addressed to STA200 or an AID for random access (e.g., 2045) is included in the AID field in the User Info field of the Trigger frame. If an AID addressed to STA200 or an AID for random access is included, STA200 may perform uplink transmission power control and generate an uplink response signal (e.g., TB-PPDU) based on the values ​​indicated in the Common Info field and the User Info field. Then, STA200 may transmit the uplink response signal to AP100 based on, for example, the determined transmission power.

[0087] Note that when the association AP individually specifies the AID of the STA 200, the cooperating APs 100 may not assign the same AID to the STA 200 among the APs 100. In other words, the cooperating APs 100 may assign different AIDs to the STA 200 among the APs 100. This makes it possible to identify the STAs 200 that perform cooperative communication within an AP group, for example. For example, an AID assignment range may be specified for each AP 100, and each AP 100 may assign an AID within the specified range to the associated STA 200.

[0088] Furthermore, each AP 100 may, for example, notify the cooperating APs 100 of its AID allocation range. When each AP 100 receives notification of its AID allocation range, it may specify an allocation range that does not overlap with the notified allocation range. This makes it possible to prevent overlapping of AID allocation ranges between APs 100. The AID allocation range of each AP 100 may be notified by a beacon.

[0089] As shown in FIG. 13 , each AP 100 may receive, for example, an uplink response signal (e.g., a TB PPDU) and transmit information (e.g., an ACK or a Block-ACK) regarding the success or failure of reception (or decoding) of the uplink response signal to the STA 200. When cooperative communication is performed, for example, the AP 100 that receives the response signal may transmit an ACK to the STA 200. For example, in diversity reception, one AP 100 that receives the uplink response signal among the APs 100 performing cooperative communication may transmit an ACK. Also, for example, in joint reception, multiple APs 100 that receive response signals may transmit ACKs. By each AP 100 that receives a response signal transmitting an ACK, ACKs can be jointly transmitted, thereby improving the ACK reception performance at the STA 200.

[0090] When joint reception is applied, the sharing AP may transmit an ACK and the shared AP may not transmit an ACK. By transmitting an ACK and the shared AP not transmitting an ACK, ACK information does not need to be communicated between APs 100.

[0091] Furthermore, the ACK is not limited to being transmitted after SIFS has elapsed since the AP 100 received the uplink response signal, but may be transmitted after a certain time has elapsed (called a Delayed ACK). For example, the ACK response method may be changed depending on the cooperative communication method. For example, in joint reception, Delayed ACK may be applied taking into account the reception synthesis processing time.

[0092] FIG. 14 is a diagram illustrating an example in which, for example, in the exemplary configuration of the wireless communication system illustrated in FIG. 8 , a 20 MHz bandwidth is assigned to STA1, a 20 MHz bandwidth to STA2, and a 40 MHz bandwidth (in other words, resources) to STA#3. In FIG. 14 , for example, when transmitting a Trigger frame, AP1 and AP2 may transmit the same (common) information to STA1, STA2, and STA3 in an 80 MHz bandwidth. STA1, STA2, and STA3 may transmit uplink response signals (e.g., TB PPDUs) in the bandwidth indicated by the Trigger frame. Furthermore, AP1 and AP2 may transmit ACKs (or BAs) to each STA in the bandwidth in which the uplink response signals from STA1, STA2, and STA3 were transmitted.

[0093] [Method for Selecting Target RSSI When Uplink Coordinated Communication is Applied] Next, an example of a method for selecting a target RSSI (for example, uplink target RSSI) for each STA 200 when uplink coordinated communication is applied, according to this embodiment, will be described.

[0094] <Selection Method 1> In selection method 1, for example, the AP 100 may select the maximum target RSSI from among the target RSSIs for each STA 200 set by each AP 100 performing cooperative communication.

[0095] As an example, an example of selecting a target RSSI for STA2 shown in Fig. 8 will be described. For example, if the target RSSI set by AP1 for STA2 is RSSI#1 and the target RSSI set by AP2 for STA2 is RSSI#2, the value of max(RSSI#1, RSSI#2) may be selected as the target RSSI for STA2.

[0096] By selecting the maximum target RSSI as the target RSSI for STA200, it becomes possible to set the highest reception level among the reception levels of the uplink response signal based on the target RSSI set for each STA200, thereby improving the probability of successfully receiving the uplink response signal at AP100.

[0097] <Selection Method 2> In selection method 2, for example, the AP 100 may select the smallest target RSSI from among the target RSSIs for each STA 200 set by each AP 100 performing cooperative communication.

[0098] As an example, an example of selecting a target RSSI for STA2 shown in Fig. 8 will be described. For example, if the target RSSI set by AP1 for STA2 is RSSI#1 and the target RSSI set by AP2 for STA2 is RSSI#2, the value of min(RSSI#1, RSSI#2) may be selected as the target RSSI for STA2.

[0099] By selecting the minimum target RSSI as the target RSSI for STA 200, it is possible to reduce interference (e.g., adjacent-channel interference (ACI)) caused by an uplink response signal transmitted from STA 200 on response signals of other STAs. This improves the probability that AP 100 will successfully receive response signals from other STAs.

[0100] <Selection Method 3> In selection method 3, for example, the AP 100 may select the average value of the target RSSI for each STA 200 set by each AP 100 that performs cooperative communication.

[0101] By selecting the average value as the target RSSI for STA 200, it is possible to maintain the reception performance of the uplink response signal at AP 100 while suppressing the ACI that the uplink response signal transmitted from STA 200 gives to other STAs.

[0102] Alternatively, the AP 100 may calculate an average value by weighting the target RSSI set for each STA 200. For example, a larger weighting coefficient may be assigned to the target RSSI of a Sharig AP, and a smaller weighting coefficient may be assigned to the target RSSI of a Shared AP.

[0103] The above has described selection methods 1 to 3. Note that the method of selecting the target RSSI for each STA 200 when uplink cooperative communication is applied is not limited to the above selection methods 1 to 3. For example, the target RSSI for a certain STA 200 may be set based on one or more target RSSIs among the target RSSIs set for that STA 200 in each AP 100.

[0104] [Trigger Frame Format for Uplink Cooperative Communication and Method for Calculating Uplink Transmission Power] Hereinafter, an example of a trigger frame format for uplink cooperative communication and a method for calculating (determining) uplink transmission power in the STA 200 according to this embodiment will be described.

[0105] In this embodiment, for example, information regarding the transmission power of the AP 100 (in other words, transmission power control parameters) may be set for each STA 200 by the Trigger frame. For example, the transmission power control parameters may include information regarding downlink transmission power determined for each of multiple STAs 200 in accordance with the type of uplink communication control (e.g., multi-AP control) based on communication between the APs 100. For example, the type of multi-AP control for each STA 200 may include, for example, a case where coordinated uplink communication control is performed and a case where coordinated uplink communication control is performed. Furthermore, when coordinated uplink communication control is performed, for example, joint transmission and diversity reception may be included.

[0106] <Example 1> Fig. 15 is a diagram showing an example of the Common Info field and the User Info field of the Trigger frame in Example 1. Note that the Common Info field and the User Info field of the Trigger frame may include fields different from those shown in Fig. 15. Also, some of the fields shown in Fig. 15 may not be included.

[0107] 15 may include, for example, "AP TX Power," a setting value (also referred to as a reference value, for example) of the transmission power of the AP 100 that is commonly used when multiple STAs 200 to which a Trigger frame is transmitted calculate uplink transmission power. "AP TX Power" may be set to, for example, the transmission power of a sharing AP, the average value (also referred to as average transmission power, for example) of the transmission power of APs 100 belonging to an AP group performing cooperative communication, or any one of the transmission powers (for example, the maximum or minimum value) of APs 100 belonging to the AP group.

[0108] Furthermore, the User Info field shown in FIG. 15 may include, for example, an offset value (for example, "AP TX Power offset") for the value "AP TX Power" that is included in the Common Info field and is common to a plurality of STAs 200.

[0109] For example, if the setting value of AP TX Power is the transmission power of the sharing AP or the average transmission power of the AP group, the value of "AP TX Power offset" may be a negative value. Therefore, for example, if the "AP TX Power offset" field is 4 bits, an offset value such as -8 to +7 [dB] may be set.

[0110] The AP 100 may determine the AP TX power offset based on, for example, a cooperative communication mode (e.g., diversity reception or joint reception, etc.). For example, in selecting the cooperative communication mode, joint reception may be applied between multiple APs 100 where the path loss between the STA 200 and the AP 100 is within X dB. On the other hand, between multiple APs 100 where the path loss is greater than X dB, diversity reception by one AP 100 with the smallest path loss may be applied, for example.

[0111] For example, for a STA 200 that applies joint reception, the STA 200 can calculate the downlink path loss by using the combined transmission power of multiple APs 100 that participate in joint reception.

[0112] As an example, the configuration of a wireless communication system shown in FIG. 8 will be described.

[0113] The setting value of "AP TX Power" in the Common Info field is, for example, the transmission power (TxPow AP1 [dBm]) may be set.

[0114] Furthermore, the setting value of "AP TX Power offset" in the User Info field for STA1 may be set to, for example, 0 [dB]. In other words, the setting value of "AP TX Power offset" for STA1 may be set to a value obtained by subtracting AP TX Power (here, the transmission power of AP1) from the transmission power of AP1.

[0115] Furthermore, the setting value of the "AP TX Power offset" in the User Info field for STA2 may be set to, for example, a value obtained by subtracting AP TX Power (here, the transmission power of AP1) from the combined power of the transmission powers of AP1 and AP2, as shown in the following equation (3), taking into account joint reception by AP1 and AP2.

[0116] In addition, the setting value of "AP TX Power offset" in the User Info field for STA3 may be set to, for example, a value obtained by subtracting AP TX Power (here, the transmission power of AP1) from the transmission power of AP2, as shown in the following equation (4).

[0117] The STA 200 may, for example, read the “AP TX Power” (e.g., Tx Pow Ap) and the "AP Tx Power offset" in the User Info field (e.g., Tx PowOffset Ap ) is set in accordance with the following equations (5) and (6), Pow STA (expressed as

[0118] As a result, for example, in Figure 8, for STA1, uplink transmission power based on the transmission power of AP1 is set, for ST2, uplink transmission power based on the combined value of the transmission powers of AP1 and AP2 is set, and for STA3, uplink transmission power based on the transmission power of AP2 is set.

[0119] Thus, in Example 1, the AP 100 notifies the STAs 200 of information regarding the transmission power for each STA 200 taking into account the cooperative communication mode (in other words, the transmission power of the AP 100 taking into account the MAP coordination process for each STA 200) using, for example, a Trigger frame. Furthermore, the STAs 200 can recognize the transmission power of the AP 100 taking into account the cooperative communication mode, for example, based on the received Trigger frame. For example, even if the transmission powers of multiple APs 100 are different, the AP 100 can notify the STAs 200 of information regarding the transmission power of the AP 100 according to their uplink transmission methods (e.g., cooperative communication modes) using the Trigger frame. Therefore, even when the cooperative communication mode is applied, each STA 200 can, for example, improve the accuracy of estimating downlink path loss and correctly calculate (determine) the uplink transmission power, thereby improving uplink throughput.

[0120] In addition, when any of the "Trigger format switching methods 4 to 6" described later is applied, the "AP TX Power offset" in the User Info field applied in the uplink cooperative communication mode may be placed in the Trigger Dependent User Info field, for example, as shown in Figure 16.

[0121] <Example 2> Fig. 17 is a diagram showing an example of the Common Info field and the User Info field of the Trigger frame in Example 2. Note that the Common Info field and the User Info field of the Trigger frame may include fields different from those shown in Fig. 17. Also, some of the fields shown in Fig. 17 may not be included.

[0122] The Common Info field (e.g., AP TX Power field) shown in Figure 17 may include, for example, a set of transmission powers (e.g., AP TxPower#1 to AP TxPower#N) that take into account the cooperative communication mode (e.g., diversity reception, joint reception, etc.) for each STA200.

[0123] For example, in the configuration example of the wireless communication system shown in Figure 8, the Common Info field may include a set of the transmission power of AP1, the transmission power of AP2, and the combined transmission power of AP1 and AP2 taking joint reception into consideration (e.g., expressed as "transmission power of AP#1 + AP#2").

[0124] The number N of sets of transmission power of the AP 100 may be determined, for example, by any of the following methods.

[0125] For example, the value of the number of sets N may be a fixed value. The value of the number of sets N may be specified (or defined) in advance in a specification, for example. The fixed value may be, for example, a value based on the maximum number of APs 100 that are expected to perform cooperative communication, or the maximum number of APs 100 taking into account the combination of APs 100 in joint reception. Setting the value of the number of sets N to a fixed value simplifies the process of generating a trigger frame in the AP 100 and the process of determining a trigger frame in the STA 200.

[0126] Also, for example, the value of the number of sets N may be a value notified (in other words, set) from the AP 100 to the STA 200. The value of the number of sets N may be notified, for example, by a beacon or control information in the negotiation phase. For example, the AP 100 can reduce signaling overhead by notifying the number of sets N in consideration of cooperative communication in the AP group.

[0127] 17 may include, for example, an index (e.g., AP TX Power index) indicating which value of the transmission power set included in the Common Info field is to be used by STA 200. In other words, the User Info field may include an index associated with information on multiple downlink transmission powers set in the Common Info field.

[0128] For example, in the configuration example of the wireless communication system shown in Fig. 8, a case will be described in which, in the Common Info field, AP TxPower #1 is set to the transmission power of AP1, AP TxPower #2 is set to the transmission power of AP2, and AP TxPower #3 is set to the transmission power of AP #1 + AP #2. In this case, index #1 may be set to the User Info field for STA1, index #3 may be set to the User Info field for STA2, and index #2 may be set to the User Info field for STA3.

[0129] The STA 200 may set, for example, the AP TX Power set (e.g., Tx Pow Ap (n), n=1, 2, ..., N)) and the AP Tx Power index (e.g., i) in the User Info field, the uplink transmission power (e.g., Tx Pow STA (expressed as

[0130] As a result, for example, in Figure 8, for STA1, uplink transmission power based on the transmission power of AP1 is set, for ST2, uplink transmission power based on the combined value of the transmission powers of AP1 and AP2 is set, and for STA3, uplink transmission power based on the transmission power of AP2 is set.

[0131] Thus, in Example 2, the AP 100 notifies the STAs 200 of information regarding the transmission power for each STA 200 taking into account the cooperative communication mode (in other words, the transmission power of the AP 100 taking into account the MAP coordination process for each STA 200) using, for example, a Trigger frame. The STAs 200 can also recognize the transmission power of the AP 100 taking into account the cooperative communication mode, for example, based on the received Trigger frame. For example, even if the transmission powers of multiple APs 100 are different, the AP 100 can notify the STAs 200 of information regarding the transmission power of the AP 100 according to their uplink transmission methods (e.g., cooperative communication modes) using the Trigger frame. Therefore, even when the cooperative communication mode is applied, each STA 200 can, for example, improve the accuracy of estimating downlink path loss and correctly calculate (determine) the uplink transmission power, thereby improving uplink throughput.

[0132] Here, with respect to the transmission power control parameters for each STA 200 included in the User Info field, the number of bits is likely to be smaller for the index value as in Example 2 compared to the offset value as in Example 1 (e.g., FIG. 15). Furthermore, in general, in a wireless communication system, the number of STAs 200 is likely to be greater than the number of APs 100. Therefore, in Example 2, for example, the greater the number of STAs 200 configured (in other words, triggered) by the Trigger frame, the more effectively the increase in the User Info field size can be suppressed compared to Example 1. This allows for a further reduction in signaling overhead.

[0133] Note that when any of "Trigger format switching methods 4 to 6" described later is applied, "AP TX Power #2 to AP TX Power #N" in the Common Info field applied in the uplink cooperative communication mode may be placed in the Trigger Dependent Common Info field, for example, as shown in Fig. 18. For example, AP TX Power #1 may be placed in the AP TX Power field shown in Fig. 18. Similarly, "AP TX Power index" in the User Info field applied in the uplink cooperative communication mode may be placed in the Trigger Dependent User Info field, as shown in Fig. 18.

[0134] The trigger frame format for uplink cooperative communication and an example of a method for calculating uplink transmission power in the STA 200 have been described above.

[0135] [Trigger frame format switching method] Next, a description will be given of a method for switching between a control signal format (Trigger frame format) when uplink coordinated communication is applied and a control signal format when uplink coordinated communication is not applied (in other words, a method for notifying the format to the STA 200). Note that format switching may be interpreted as format selection, or format determination or setting.

[0136] For example, when at least one STA 200 among a plurality of STAs 200 instructed to transmit an uplink response signal by the Trigger frame performs uplink cooperative communication, the format of the control signal when uplink cooperative communication is applied may be applied.

[0137] On the other hand, for example, if each of multiple STAs 200 (e.g., all STAs 200) that are instructed to send an uplink response signal by a trigger frame does not perform uplink cooperative communication, the format of the control signal when uplink cooperative communication is not applied may be applied.

[0138] For example, the AP 100 and the STA 200 may switch the format of the trigger frame based on any of switching methods 1 to 6 described below. For example, the AP 100 and the STA 200 may determine a trigger frame format when applying A uplink cooperative communication control (e.g., uplink communication control coordinated between APs 100) and a trigger frame format when uplink cooperative communication control is not performed, based on information related to the coordination of multi-AP control (e.g., flag information or a trigger type described below). This makes it possible to reduce signaling overhead when multiple STAs 200 instructed to send uplink response signals by the trigger frame do not perform uplink cooperative communication.

[0139] <Switching Method 1> In switching method 1, the AP 100 may notify the STA 200 of control information including flag information indicating whether or not to perform uplink cooperative communication.

[0140] For example, as shown in FIG. 19, information indicating whether or not uplink cooperative communication is applied (for example, "UL multi AP flag") may be included in the Common Info field.

[0141] For example, when the UL multi AP flag is 1, a control signal format for STA 200 during uplink cooperative communication may be applied as in Example 1 or Example 2. On the other hand, for example, when the UL multi AP flag is 0, a control signal format for STA 200 during uplink cooperative communication may not be applied. For example, when the UL multi AP flag is 0, a control signal format similar to that of 11ax may be applied.

[0142] For example, when the STA 200 receives a Trigger frame, the STA 200 may determine which format is to be applied to the Trigger frame (control signal) based on the UL multi AP flag in the Common Info field.

[0143] <Switching Method 2> In Switching Method 2, for example, the AP 100 may notify information indicating whether or not to apply a format of a control signal for the STA 200 during uplink cooperative communication (for example, a UL multi AP flag similar to that in Switching Method 1) in a signal field (for example, a Universal-SIG (U-SIG) or an EHT-SIG) in a preamble of a downlink PPDU including a Trigger frame.

[0144] <Switching Method 3> In Switching Method 3, for example, the AP 100 may notify the STA 200 of information indicating whether to apply a format of a control signal for the STA 200 during uplink cooperative communication in a beacon or control information (for example, a UL multi AP flag similar to that in Switching Method 1).

[0145] <Switching Method 4> In switching method 4, for example, the AP 100 may instruct the STA 200 on the format of the control signal by using "Trigger type" included in the Common Info field of the Trigger frame.

[0146] In switching method 4, for example, the multi-AP application mode may be set for at least one of the modes such as Basic and Beamforming Report Poll (BFRP) in the Trigger Type subfield value.

[0147] Fig. 20 is a diagram illustrating an example of a trigger type according to switching method 4. Fig. 20 illustrates, for example, an example of a relationship between a trigger type (for example, a trigger frame variant) and a value (trigger type subfield value) associated with the trigger type notified from the AP 100 to the STA 200 by a trigger frame (for example, a common info field).

[0148] In the example shown in Fig. 20 , a combination of Basic and multi-AP application mode is set as the Trigger type in the Trigger Type subfield value = 8. Note that the setting of the Trigger type shown in Fig. 20 is an example, and a Trigger frame type other than Basic and the multi-AP application mode may be notified.

[0149] When the Trigger type is a type corresponding to uplink cooperative communication (for example, multi-AP application mode), the AP 100 and the STA 200 may set a Trigger frame format for when uplink cooperative communication is applied.

[0150] Switching method 4 eliminates the need to add a new field or format for controlling the switching of the control signal format, thereby suppressing an increase in the number of changes in specifications.

[0151] <Switching Method 5> In switching method 5, for example, the AP 100 may instruct the STA 200 on the format of the control signal by using "Trigger type" included in the Common Info field of the Trigger frame.

[0152] FIG. 21 is a diagram showing an example of a trigger type according to switching method 5.

[0153] As shown in FIG. 21, AP 100 may notify STA 200 whether the Trigger format is for uplink cooperative communication, for example, by using a field different from the Trigger Type subfield value (for example, a Multi-AP operation flag (for example, 1 bit)).

[0154] <Switching Method 6> In switching method 6, for example, the AP 100 may instruct the STA 200 on the format of the control signal by using "Trigger type" included in the Common Info field of the Trigger frame.

[0155] Fig. 22 is a diagram illustrating an example of a trigger type according to switching method 6. Fig. 22 illustrates, for example, an example of a relationship between a trigger type (for example, a trigger frame variant) and a value (trigger type subfield value) associated with the trigger type notified from the AP 100 to the STA 200 by a trigger frame (for example, a common info field).

[0156] As shown in Fig. 22 , for example, "Trigger type" may indicate that uplink cooperative communication (multi-AP) will be performed. In the example shown in Fig. 22 , when the Trigger Type subfield value = 8, it may indicate that uplink cooperative communication will be performed.

[0157] Furthermore, when the application of uplink cooperative communication is notified by the Trigger type (for example, when the Trigger Type subfield value = 8), the type of the Trigger frame (for example, Basic or BFRP) may be notified in a field different from the Trigger type (for example, Trigger Info in the Trigger Dependent Common Info field), as shown in Fig. 23. For example, the type of the Trigger format notified in the Trigger Info may be the same as the content shown in Fig. 5 (for example, the Trigger type of 11ax).

[0158] For example, when the Trigger type is a type corresponding to uplink cooperative communication (for example, multi-AP application mode), the AP 100 and the STA 200 may set a Trigger frame format for when uplink cooperative communication is applied.

[0159] The above explains how to switch the trigger frame format.

[0160] As described above, in this embodiment, the AP 100 notifies the STAs 200 of parameters related to uplink transmission power control when performing uplink cooperative communication (e.g., parameters related to the transmission power of the AP 100 for each STA 200) by using the Trigger frame. Furthermore, the STAs 200 control the transmission power of the uplink response signal based on the parameters related to uplink transmission power control included in the received Trigger frame, for example.

[0161] This allows each STA 200 to calculate the transmission power of the uplink response signal based on the transmission power control parameter (transmission power of AP 100) for each STA 200 included in the Trigger frame. Therefore, even if the transmission power of multiple APs 100 in an AP group is different, each STA 200 can improve the estimation accuracy of the downlink path loss and improve the accuracy of the transmission power control of the uplink response signal, thereby improving the uplink throughput.

[0162] Therefore, according to this embodiment, uplink transmission power can be flexibly set (controlled) for each STA 200 in Multi-AP coordination.

[0163] In the first embodiment, for example, a method for notifying each STA of the transmission power of the AP 100 in consideration of cooperative communication control in a trigger frame has been described. In the present embodiment, a method for notifying the STA 200 of information related to the transmission power of each AP 100 in an AP group (for example, the downlink transmission power of each AP 100 related to multi-AP control) in a trigger frame will be described.

[0164] The configuration example of the AP 100 and the STA 200 according to this embodiment may be the same as the configuration example of the first embodiment.

[0165] Hereinafter, examples of trigger frame formats for uplink cooperative communication and methods for calculating uplink transmission power according to the present embodiment will be described. Note that, in the present embodiment, the trigger frame format may be switched in the same manner as in the first embodiment (e.g., any one of switching methods 1 to 6).

[0166] <Example 3> Fig. 24 is a diagram showing an example of the Common Info field and the User Info field of the Trigger frame in Example 3. Note that the Common Info field and the User Info field of the Trigger frame may include fields different from those shown in Fig. 24. In addition, some of the fields shown in Fig. 24 may not be included.

[0167] The Common Info field (e.g., AP TX Power field) shown in FIG. 24 may include, for example, the transmission power of each AP 100 in the AP group (e.g., AP TX Power #1 to AP TX Power #N).

[0168] Note that N may be a fixed value, for example, as in Example 2 of Embodiment 1, or may be notified from the AP 100 to the STA 200 by a beacon or control information. Also, if the number of APs 100 in the AP group is less than N, there may be an unused region in the AP TX Power field.

[0169] For example, in the configuration example of the wireless communication system shown in FIG. 8, in the Common Info field, the transmission power of AP1 may be set to AP TX Power #1, and the transmission power of AP2 may be set to AP TX Power #2.

[0170] 24 may include, for example, an "AP TX Power index" having the same number of bits (N) as the number N of transmission powers for each AP 100 set in the Common Info field. Each bit of the AP TX Power index (for example, AP TX Power index#n, n=1, 2, ..., N) may correspond to each of AP TX Power#1 to AP TX Power#N set in the Common Info field. In other words, the N bits of the AP TX Power index may be bitmap information corresponding to each of AP TX Power#1 to AP TX Power#N.

[0171] For example, when the value of each bit of the AP TX Power index (e.g., AP TX Power index #n, n = 1, 2, ..., N) is 1, the STA 200 may calculate the uplink transmission power using the AP TX Power set in the corresponding Common Info field. Also, for example, when multiple bits of the AP TX Power index are 1, the STA 200 may calculate the uplink transmission power by combining multiple AP TX Power values ​​corresponding to the multiple bits. For example, when joint reception is applied, multiple AP TX Power indices corresponding to multiple APs 100 that receive an uplink response signal from the STA 200 may be set to 1.

[0172] The STA 200 may, for example, receive the AP TX Power (e.g., Tx Pow Ap (n), (n=1, 2, ..., N)), and the AP Tx Power index (for example, i) in the User Info field, the uplink transmission power (for example, Tx Pow STA (expressed as

[0173] As shown in equations (9) and (10), the STA 200 uses the transmission power Tx of the AP 100, for example, when the value of the AP Tx Power index(i) is set to 1. Pow Ap (i) is added to the value Tx Pow Ap Based on the path loss PL DL Estimate.

[0174] For example, in the example configuration of the wireless communication system shown in Fig. 8, a case will be described in which the transmission power of AP1 is set in AP TxPower#1, the transmission power of AP2 is set in AP TxPower#2, and N is 2 bits. In this case, for example, the AP TX Power index in the User Info field of STA1 may be set to "10", the AP TX Power index in the User Info field of STA2 may be set to "11", and the AP TX Power index in the User Info field of STA3 may be set to "01".

[0175] As a result, for example, in Figure 8, STA1 calculates the uplink transmission power based on the transmission power of AP1, ST2 calculates the uplink transmission power based on the combined value of the transmission powers of AP1 and AP2, and STA3 calculates the uplink transmission power based on the transmission power of AP2.

[0176] Thus, in Example 3, for example, the transmission power of each AP 100 in the AP group is set (in other words, notified) by the Trigger frame. The STA 200 can recognize the transmission power of the AP 100 taking into account the cooperative communication mode, for example, based on the received Trigger frame. For example, even if the transmission powers of multiple APs 100 are different, the STA 200 can recognize (or select) information regarding the transmission power of the AP 100 according to the uplink transmission method (e.g., cooperative communication mode) of each STA 200 by the Trigger frame. Therefore, even when the cooperative communication mode is applied, each STA 200 can, for example, improve the estimation accuracy of downlink path loss and correctly calculate (determine) the uplink transmission power, thereby improving uplink throughput.

[0177] Note that when any of "Trigger format switching methods 4 to 6" described in the first embodiment is applied, "AP TX Power #2 to AP TX Power #N" in the Common Info field applied in the uplink cooperative communication mode may be placed in the Trigger Dependent Common Info field, for example, as shown in Fig. 25. For example, AP TX Power #1 may be placed in the AP TX Power field shown in Fig. 25. Similarly, "AP TX Power index" in the User Info field applied in the uplink cooperative communication mode may be placed in the Trigger Dependent User Info field, as shown in Fig. 25.

[0178] <Example 4> In Example 4, similarly to Example 3, for example, the transmission power (for example, AP TX Power#1 to AP TX Power#N) for each AP 100 in the AP group may be included in the Common Info field of the Trigger frame.

[0179] On the other hand, in Example 4, for example, information on the transmission power of the AP 100 used to calculate the uplink transmission power (for example, "AP TX Power index" in Example 3) may not be indicated in the User Info field of the Trigger frame. For example, as shown in FIG. 26 , the User Info field may have the same format as that of 11ax.

[0180] The STA 200 may select the transmission power to be used for calculating the uplink transmission power from among the transmission powers of the multiple APs 100 notified in the Common Info field of the Trigger frame, for example.

[0181] STA200 may, for example, estimate the path loss in communication with each AP100, and calculate the uplink transmission power for each destination (AP100) based on the transmission power for each AP100 notified in the Common Info field and the estimated path loss.

[0182] Here, the EHT-LTFs between the APs 100 of the AP group may be orthogonal for path loss estimation between each AP 100. As a method for orthogonalizing the EHT-LTFs, for example, a method using different frequency resources or different codes (e.g., orthogonal codes) may be applied.

[0183] Furthermore, the STA 200 may estimate the path loss between each AP 100 without using, for example, orthogonal EHT-LTF. For example, it is assumed that the path loss difference between APs 100 performing cooperative communication is small (for example, the path loss difference is equal to or less than a threshold value). Therefore, the STA 200 may assume that there is no difference between the path losses corresponding to each of the multiple APs 100 (for example, equal to or less than a threshold value), and estimate the path loss estimated based on non-orthogonal EHT-LTF as the path loss of each AP 100.

[0184] The STA 200 may determine the final uplink transmission power based on the uplink transmission power calculated for each transmission destination (AP 100), for example, by one of the following selection methods.

[0185] (1) The STA 200 may select, for example, the minimum uplink transmission power from among the calculated uplink transmission powers. By selecting the minimum uplink transmission power, the power consumption of the STA 200 can be reduced.

[0186] (2) The STA 200 may select, for example, the maximum uplink transmission power from the calculated uplink transmission powers. By selecting the maximum uplink transmission power, the reception quality of the uplink response signal can be improved, and the uplink throughput can be improved.

[0187] (3) The STA 200 may set the calculated average value of the uplink transmission power of the transmission destination (AP 100) as the uplink transmission power. This may reduce the power consumption of the STA 200 and improve the reception quality of the uplink response signal.

[0188] The method for selecting the uplink transmission power is not limited to these. For example, the uplink transmission power may be set to a weighted average value of the calculated uplink transmission power of the destination (AP 100).

[0189] Thus, in Example 4, for example, the transmission power of each AP 100 in the AP group is set (in other words, notified) by the Trigger frame. The STA 200 can recognize the transmission power of the AP 100 taking into account the cooperative communication mode, for example, based on the received Trigger frame. For example, even if the transmission powers of multiple APs 100 are different, the STA 200 can recognize (or select) information regarding the transmission power of the AP 100 according to the uplink transmission method (e.g., cooperative communication mode) of each STA 200 by the Trigger frame. Therefore, even when the cooperative communication mode is applied, each STA 200 can, for example, improve the estimation accuracy of downlink path loss and correctly calculate (determine) the uplink transmission power, thereby improving uplink throughput.

[0190] In addition, in Example 4, for example, the STA 200 can dynamically switch the AP 100 to which it transmits (for example, diversity reception), which can improve the reception quality of uplink response signals or reduce power consumption.

[0191] As described above, in this embodiment, the AP 100 notifies the STAs 200 of parameters related to uplink transmission power control that take uplink cooperative communication into consideration (e.g., parameters related to uplink transmission power control for each of the multiple STAs 200) by using the Trigger frame. Furthermore, the STAs 200 control the transmission power of the uplink response signal, for example, based on the parameters related to transmission power control included in the received Trigger frame.

[0192] As a result, each STA 200 can calculate the transmission power of the uplink response signal based on the transmission power control parameters (transmission power of the AP 100) for each AP 100 included in the Trigger frame. Therefore, even if the transmission powers of multiple APs 100 in an AP group are different, each STA 200 can improve the estimation accuracy of the downlink path loss, thereby improving the accuracy of the transmission power control of the uplink response signal and improving the uplink throughput.

[0193] Therefore, according to this embodiment, uplink transmission power for each STA 200 can be flexibly set (controlled) in Multi-AP coordination.

[0194] In the first and second embodiments, the notification method of the transmission power of the AP for uplink cooperative communication has been described. In the present embodiment, a notification method of the target RSSI (for example, target received signal strength) of the uplink will be described.

[0195] The configuration examples of the AP 100 and the STA 200 according to this embodiment may be the same as the configuration examples of embodiment 1. For example, the operation of the STA-directed control signal generating unit 102 of the AP 100 differs from that of embodiment 1 or embodiment 2, and therefore an operation example will be described below.

[0196] The STA control signal generating unit 102 may generate a control signal for the STA 200 based on, for example, the result of resource allocation to each STA 200, transmission power control parameters (e.g., AP TX Power or target RSSI, etc.) input from the setting unit 101, or information input from the received signal demodulation / decoding unit 106.

[0197] The control signal for STA200 may include, for example, time and frequency resource information (e.g., RU allocation information for uplink cooperative communication, TXOP, LENGTH, etc.), as well as at least one of the following: transmission power control parameters (e.g., transmission power of AP100 or target RSSI, etc.), information regarding trigger frame generation (e.g., UL MCS, GI, LTF mode), a trigger type that notifies the type of control signal, and terminal identification information (e.g., AID).

[0198] Furthermore, in this embodiment, for example, by adjusting the target RSSI, the dynamic range of the target RSSI may become larger compared to when uplink cooperative communication is not applied. Therefore, in this embodiment, when uplink cooperative communication is applied, the format of the target RSSI field may be changed compared to when uplink cooperative communication is not applied (an example will be described later).

[0199] The STA-directed control signal generating unit 102 outputs the generated control signal to the transmission signal generating unit 104, for example.

[0200] [Method of Adjusting Target RSSI] Hereinafter, an example of a method of adjusting target RSSI in this embodiment will be described.

[0201] AP100 may adjust the "target RSSI" in the User Info field based on, for example, the "AP TX Power" set in the Common Info field of the Trigger frame, the transmission power of each AP100 in the AP group, and the cooperative communication mode applied to each STA200.

[0202] For example, the AP 100 may adjust the target RSSI according to the following equation (12).

[0203] In equation (12), Target RSSI_adj (u) represents the adjusted target RSSI [dBm] for STA#u. RSSI (u) represents the target RSSI [dBm] before adjustment for STA#u. The target RSSI before adjustment may be the target RSSI set by the same method as in the first or second embodiment, for example.

[0204] In addition, in equation (12), Tx Pow Ap represents the AP TX Power [dBm] set in the Common Info field, and Tx Pow Ap(u) represents the transmission power [dBm] of at least one AP 100 that receives the uplink response signal transmitted from STA#u.

[0205] Tx Pow Ap For example, the transmission power of the sharing AP may be set in Tx Pow ApThe value is not limited to the transmission power of the sharing AP, but may be the average transmission power of the AP group performing cooperative communication, or may be the transmission power of any AP 100 in the AP group (e.g., the maximum or minimum transmission power).

[0206] Also, for example, Tx for the STA 200 that does not perform uplink cooperative communication Pow Ap(u) On the other hand, the transmission power of the STA 200 in the diversity reception cooperative communication mode may be set to Tx Pow Ap(u) For example, the transmission power of the AP 100 that receives the uplink response signal may be set in the Tx Pow Ap(u) For example, the total value of the transmission power of multiple APs 100 that receive uplink response signals may be set to .

[0207] As shown in equation (12), the adjusted target RSSI (Target RSSI_adj For example, the transmission power of one or more APs 100 performing cooperative communication is reflected in (u). Therefore, the STA 200 can calculate the uplink transmission power according to the cooperative communication mode set for each STA 200, for example, based on the target RSSI notified by the trigger frame.

[0208] [Format of target RSSI field] An example of the format of the target RSSI field will be described.

[0209] For example, even if the dynamic range of the target RSSI increases due to adjustment of the target RSSI, a format may be applied that enables the desired target RSSI to be notified in the User Info field of the Trigger frame.

[0210] For example, as will be described later, by setting (or changing) the format of the target RSSI field, the AP 100 can notify the STA 200 of the desired target RSSI, thereby improving the accuracy of uplink transmission power control in the STA 200.

[0211] In this embodiment, the trigger frame format may be switched, for example, in the same manner as in the first embodiment (for example, any one of switching methods 1 to 6).

[0212] <Target RSSI Format 1> For example, the number of bits corresponding to the target RSSI setting value in the target RSSI field may be increased. For example, in 11ax, the number of bits in the target RSSI field is 7 bits. In this embodiment, for example, the number of bits may be more than 7 bits (e.g., 8 bits) in consideration of an increase in the dynamic range of target RSSI due to uplink cooperative communication.

[0213] In other words, the bit size corresponding to the information regarding the target RSSI may be different depending on whether uplink cooperative communication control (e.g., cooperative uplink communication control between APs 100) is performed or not.

[0214] Furthermore, for example, a part of the reserve area set in the target RSSI field (for example, a table) in 11ax shown in Fig. 4 may be used as the increase in bits corresponding to the set value of target RSSI. In this case, it is not necessary to increase the number of bits in the target RSSI field.

[0215] <Target RSSI Format 2> Fig. 27 shows an example of a target RSSI field (e.g., a table). Fig. 20 shows an example of the relationship between the target RSSI value (or candidate value, e.g., a range of -155 dBm to 25 dBm) and the index value (e.g., any one of 0 to 127) notified from the AP 100 to the STA 200 by the Trigger frame (e.g., User Info field).

[0216] As shown in Fig. 27, for example, the settable target RSSI range may be expanded by increasing the step size of the target RSSI (for example, increasing the maximum value and decreasing the minimum value) compared to the setting values ​​shown in Fig. 4. For example, the step size of the target RSSI is 1 dB in 11ax and 2 dB in Fig. 27.

[0217] In other words, the difference (in other words, the step width) between the target RSSIs associated with the two indices associated with the candidate values ​​of the target RSSI may be different between when uplink cooperative communication control (e.g., uplink communication control coordinated between APs 100) is performed and when uplink cooperative communication control is not performed.

[0218] Note that FIG. 27 is just an example, and for example, the range of either the maximum value or the minimum value may be expanded, and the step width may be a step width other than 2 dB (for example, 1.5 dB).

[0219] Furthermore, regarding whether or not to apply "target RSSI format 2," the STA 200 may switch based on, for example, the setting value of the "AID12" field in the User Info field. For example, when an AID reserved separately for cooperative communication (e.g., an AID for cooperative communication) is specified, the STA 200 may apply a target RSSI table (e.g., FIG. 27) with an increased RSSI step size, and when an AID different from the AID for cooperative communication is specified, the STA 200 may use a target RSSI table (e.g., FIG. 4) with an RSSI step size of 1 dB. In other words, the STA 200 may change the step size or range (maximum value, minimum value) of the target RSSI based on, for example, the AID specified by the Trigger frame.

[0220] The AID for cooperative communication may be, for example, any of the AIDs 2047 to 4094 reserved in 11ax, or an AID indicated by a beacon or control information.

[0221] An example of the format of the target RSSI field has been described above.

[0222] In the present embodiment, for example, by using a method of reporting a target RSSI that takes into account uplink cooperative communication control, it is possible to improve the accuracy of uplink transmission power control in uplink cooperative communication, as in Embodiments 1 and 2. Furthermore, according to the present embodiment, it is only necessary to change the method of reporting a target RSSI from the method of reporting a control signal in 11ax, for example, and therefore it is possible to suppress changes in specifications.

[0223] Fourth Embodiment The configuration example of the AP 100 and the STA 200 according to this embodiment may be the same as the configuration example of the first embodiment.

[0224] In the first to third embodiments, a method has been described in which a plurality of APs 100 control uplink transmission power for uplink cooperative communication in one trigger frame. In the present embodiment, a method will be described in which each AP 100 generates a trigger frame for each AP 100 (in other words, a trigger frame for each AP 100), and controls uplink transmission power for uplink cooperative communication using a plurality of trigger frames.

[0225] In this embodiment, the operation of the STA-directed control signal generating unit 102 of the AP 100 is different from that of the other embodiments, and therefore an example of the operation will be described below.

[0226] The STA control signal generating unit 102 may generate a control signal for the STA 200 based on, for example, the result of resource allocation to each STA 200, transmission power control parameters (e.g., AP TX Power or target RSSI, etc.) input from the setting unit 101, or information input from the received signal demodulation / decoding unit 106.

[0227] The control signal for STA200 may include, for example, time and frequency resource information (e.g., RU allocation information for uplink cooperative communication, TXOP, LENGTH, etc.), as well as at least one of the following: transmission power control parameters (e.g., transmission power of AP100 or target RSSI, etc.), information regarding trigger frame generation (e.g., UL MCS, GI, LTF mode), a trigger type that notifies the type of control signal, and terminal identification information (e.g., AID).

[0228] In this embodiment, the STA control signal generating unit 102 may individually generate trigger frames for the number of APs in the AP group. In other words, the STA control signal generating unit 102 may generate trigger frames for each AP 100 in the AP group. An example of the configuration of the trigger frame will be described later.

[0229] The STA-directed control signal generating unit 102 outputs the generated control signals to the transmission signal generating unit 104, for example.

[0230] [Configuration Example of Trigger Frame] Hereinafter, a configuration example of a trigger frame according to this embodiment will be described.

[0231] <Configuration Example 1> In configuration example 1, for example, the User Info field of the Trigger frame corresponding to each AP 100 may include information regarding the STA 200 that is to receive an uplink response signal at the corresponding AP 100 (in other words, the STA 200 that sets the corresponding AP 100 as its transmission destination).

[0232] Furthermore, in configuration example 1, for example, when joint reception is applied, the same AID may be set in each of the trigger frames of the multiple APs 100 that receive the uplink response.

[0233] For example, a configuration example of a wireless communication system shown in Fig. 8 will be described. Fig. 28 is a diagram showing a configuration example of a trigger frame according to configuration example 1. As shown in Fig. 28, a trigger frame may be generated for each AP 100 (e.g., AP1 and AP2). In the example of Fig. 8, the trigger frame for AP1 may include a user info field for each of STA1 and STA2. Also, in the example of Fig. 8, the trigger frame for AP2 may include a user info field for each of STA2 and STA3.

[0234] STA200 may, for example, decode multiple Trigger frames in a received downlink PPDU (e.g., EHT PPDU or MU PPDU), and perform uplink transmission power control based on the target RSSI set in the User Info field containing the AID addressed to STA200 and the AP TX Power included in the Common Info field of the Trigger frame containing the AID addressed to STA200.

[0235] 28 , STA1 may calculate uplink transmission power based on the target RSSI set in the User Info field for STA1 included in the Trigger frame for AP1 and the AP TX Power set in the Common Info field of the Trigger frame for AP1. Also, STA3 may calculate uplink transmission power based on the target RSSI set in the User Info field for STA3 included in the Trigger frame for AP2 and the AP TX Power set in the Common Info field of the Trigger frame for AP2.

[0236] Also, for example, in the example of Figure 28, STA2 may calculate the uplink transmission power based on the target RSSI set in the User Info field for STA2 included in each of the Trigger frames for AP1 and AP2, and the AP TX Power set in the Common Info field of each of the Trigger frames for AP1 and AP2.

[0237] In addition, if the same AID (for example, the AID of STA2 shown in Figure 28) is included in multiple Trigger frames, the STA200 corresponding to that AID may calculate the uplink transmission power, for example, by adding up the AP TX Power of each Trigger frame as the transmission power of the AP.

[0238] Furthermore, when the same AID is included in multiple Trigger frames, the STA200 corresponding to that AID may select the average, maximum, or minimum target RSSI, for example, when the target RSSI set in each User Info field is different.

[0239] According to the configuration example 1, the STA 200 can recognize the transmission power of each AP 100, for example, and can control the uplink transmission power taking into account the cooperative communication mode, thereby improving the uplink throughput.

[0240] Configuration Example 2 Configuration Example 2 differs from configuration example 1 in the method of notifying transmission power control parameters when joint transmission is applied.

[0241] For example, in configuration example 2, information (for example, a "multi-AP mode" field) indicating whether or not a cooperative communication mode (for example, joint transmission) is applied may be set in the User Info field. Also, in configuration example 2, for example, it is not necessary to notify multiple AIDs (for example, the same AID) in the Trigger frame corresponding to each of the multiple APs 100. For example, the User Info field corresponding to each of the multiple AIDs may be set in any one of the Trigger frames corresponding to the multiple APs 100.

[0242] For example, the configuration example of the wireless communication system shown in Fig. 8 will be described. Fig. 29 is a diagram showing a configuration example of a trigger frame according to configuration example 2. As shown in Fig. 29, a trigger frame may be generated for each AP 100 (e.g., AP1 and AP2). In the example of Fig. 8, the trigger frame for AP1 may include a user info field for each of STA1 and STA2. Also, in the example of Fig. 8, the trigger frame for AP2 may include a user info field for each of STA3.

[0243] For example, when Joint reception is indicated in the multi-AP mode field included in the User Info field for the STA 200, the STA 200 may calculate the uplink transmission power by using the sum of the AP TX Powers of multiple Trigger frames included in the PPDU as the AP transmission power. On the other hand, when a mode other than Joint transmission (e.g., no cooperative communication or diversity reception) is indicated in the multi-AP mode field included in the User Info field for the STA 200, the STA 200 may calculate the uplink transmission power based on the AP TX Power set in the Common Info field of the Trigger frame whose User Info field includes the AID of the STA 200.

[0244] In the example of Fig. 29, a mode different from Joint transmission is indicated in the multi-AP mode field for STA1. Therefore, STA1 may calculate uplink transmission power based on the AP TX Power set in the Common Info field of the Trigger frame for AP1, which includes the User Info field for STA1. Similarly, in the example of Fig. 29, a mode different from Joint transmission is indicated in the multi-AP mode field for STA3. Therefore, STA3 may calculate uplink transmission power based on the AP TX Power set in the Common Info field of the Trigger frame for AP2, which includes the User Info field for STA3.

[0245] 29 , joint transmission is indicated in the multi-AP mode field for STA2. Therefore, STA2 may calculate uplink transmission power based on the sum of AP TX Power values ​​set in the Common Info field of each of the trigger frames for multiple APs (AP1 and AP2).

[0246] According to the second configuration example, the STA 200 can recognize the transmission power of each AP 100, and can control the uplink transmission power taking into account the cooperative communication mode, thereby improving the uplink throughput. Also, in the second configuration example, the User Info field corresponding to the same AID is not set in multiple Trigger frames, so that, for example, the more the number of STAs 200 performing joint reception, the more the signaling overhead can be reduced compared to the first embodiment.

[0247] Fifth Embodiment The configuration example of the AP 100 and the STA 200 according to this embodiment may be the same as the configuration example of the first embodiment.

[0248] In the fourth embodiment, a configuration has been described in which a plurality of APs 100 transmit a single downlink PPDU including a plurality of Trigger frames for each AP 100. In the present embodiment, for example, each of the plurality of APs 100 transmits a downlink PPDU including a Trigger frame corresponding to each AP 100 by allocating it to a different frequency resource.

[0249] In this embodiment, the operation of the STA-directed control signal generating unit 102 of the AP 100 is different from that of the other embodiments, and therefore an example of the operation will be described below.

[0250] The STA control signal generating unit 102 may generate a control signal for the STA 200 based on, for example, the result of resource allocation to each STA 200, transmission power control parameters (e.g., AP TX Power or target RSSI, etc.) input from the setting unit 101, or information input from the received signal demodulation / decoding unit 106.

[0251] The control signal for STA200 may include, for example, time and frequency resource information (e.g., RU allocation information for uplink cooperative communication, TXOP, LENGTH, etc.), as well as at least one of the following: transmission power control parameters (e.g., transmission power of AP100 or target RSSI, etc.), information regarding trigger frame generation (e.g., UL MCS, GI, LTF mode), a trigger type that notifies the type of control signal, and terminal identification information (e.g., AID).

[0252] In this embodiment, the STA-directed control signal generating unit 102 generates a control signal for the STA 200 associated with each AP 100, for example.

[0253] [Resource Allocation Method] An example of a resource allocation method for control signals will be described below.

[0254] Each AP 100 in the AP group may allocate a downlink PPDU including a trigger frame in, for example, a different frequency resource.

[0255] Fig. 30 is a diagram showing an example of resource allocation for a PPDU (for example, an EHT PPDU or an MU PPDU) including a Trigger frame. Note that the example shown in Fig. 30 shows resource allocation in the example configuration of the wireless communication system shown in Fig. 8.

[0256] For example, in Fig. 30, AP1 may allocate a downlink PPDU including a trigger frame to a 40 MHz channel including a primary channel for AP1 (P20 for AP1) and transmit the downlink PPDU. Similarly, AP#2 may allocate a downlink PPDU including a trigger frame to a 40 MHz channel including a primary channel for AP2 (P20 for AP2) and transmit the downlink PPDU. As a result, STA200 receives the trigger frame from AP1 and the trigger frame from AP2, for example, in different frequency resources.

[0257] The configuration of the Trigger frame when performing cooperative communication may be the same as, for example, either Configuration Example 1 or Configuration Example 2 of the fourth embodiment. For example, when Configuration Example 1 is applied, a User Info field in which the AID of the STA 200 to which joint reception is applied is set may be included in each Trigger frame from each AP 100. Furthermore, when Configuration Example 2 is applied, a "multi-AP mode" field may be placed in the User Info field of the Trigger frame from each AP 100.

[0258] Furthermore, in this embodiment, for example, as described in Example 4 of Embodiment 2, the STA 200 may determine the transmission power of the AP 100 to be used for transmission power calculation based on the transmission power of the multiple APs 100 notified by multiple Trigger frames. For example, in this embodiment, as shown in Fig. 30, the downlink PPDU including the Trigger frame of each AP 100 is transmitted using different frequency resources, so that the STA 200 can improve the accuracy of estimating the downlink signal from each AP 100 and improve the accuracy of estimating the path loss of each AP 100.

[0259] According to this embodiment, the STA 200 can recognize the transmission power of each AP 100, for example, and can control the uplink transmission power taking into account the cooperative communication mode, thereby improving the uplink throughput.

[0260] It should be noted that the fourth embodiment and the fifth embodiment may be combined. For example, a downlink PPDU transmitted using some frequency resources may include trigger frames of a plurality of APs 100, and a downlink PPDU transmitted using other frequency resources may include a trigger frame of one AP 100.

[0261] The embodiments of the present disclosure have been described above.

[0262] (Other Embodiments) In the above embodiment, a configuration example based on the 11ax control signal format has been described as an example, but the format to which an embodiment of the present disclosure is applied is not limited to the 11ax format.

[0263] Furthermore, the formats shown in the above embodiments are merely examples, and the present disclosure is not limited thereto. For example, some of the fields and subfields included in the formats shown in the above embodiments may be omitted, fields and subfields that notify other information may be added, or the order of the fields and subfields may be changed. Furthermore, the terms "field" and "subfield" may be interpreted interchangeably.

[0264] Furthermore, the names of the information and fields shown in the above embodiments are merely examples, and the present disclosure is not limited to these.

[0265] Furthermore, in the above-described embodiments, uplink communication has been described, but the present disclosure is not limited to this and may be applied to downlink communication.

[0266] Furthermore, in the above-described embodiments, the wireless communication system has been described as including a plurality of STAs 200, but the wireless communication system may include only one STA 200. For example, control information of an uplink signal for one STA 200 may be transmitted by a trigger frame.

[0267] Furthermore, the expression "... section" in the above embodiments may be replaced with other expressions such as "... circuitry", "... device", "... unit", or "... module".

[0268] The present disclosure can be realized by software, hardware, or software integrated with hardware. Each functional block described in the above embodiments may be partially or entirely realized as an LSI, which is an integrated circuit. Each process described in the above embodiments may be partially or entirely controlled by a single LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of a single chip that includes some or all of the functional blocks. The LSI may have data inputs and outputs. Depending on the level of integration, an LSI may be referred to as an IC, system LSI, super LSI, or ultra LSI. The integrated circuit implementation is not limited to LSIs, and may be realized using dedicated circuits, general-purpose processors, or dedicated processors. Furthermore, a field programmable gate array (FPGA), which can be programmed after LSI fabrication, or a reconfigurable processor, which allows the connections and settings of circuit cells within an LSI to be reconfigured, may also be used. The present disclosure may be realized as digital or analog processing. Furthermore, if an integrated circuit technology that can replace LSI emerges due to advances in semiconductor technology or other derivative technologies, it is natural that such technology may be used to integrate functional blocks. The application of biotechnology, etc. is also a possibility.

[0269] The present disclosure may be implemented in any type of apparatus, device, or system (collectively referred to as a communications apparatus) that has a communications function. The communications apparatus may include a radio transceiver and processing / control circuitry. The radio transceiver may include a receiver and a transmitter, or both functions. The radio transceiver (transmitter and receiver) may include a radio frequency (RF) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or the like. Non-limiting examples of communication devices include telephones (e.g., cell phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smartwatches, tracking devices), game consoles, digital book readers, telehealth / telemedicine devices, communication-enabled vehicles or mobile transportation (e.g., cars, airplanes, ships), and combinations of the above devices.

[0270] The communication devices are not limited to portable or mobile devices, but also include any kind of non-portable or fixed equipment, devices, and systems, such as smart home devices (such as home appliances, lighting equipment, smart meters or measuring devices, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0271] Communications include data communications via cellular systems, wireless LAN systems, communication satellite systems, and the like, as well as data communications via combinations of these.

[0272] A communications apparatus also includes devices such as controllers and sensors connected or coupled to a communications device that performs the communications functions described in this disclosure, such as controllers and sensors that generate control and data signals used by the communications device to perform the communications functions of the communications apparatus.

[0273] The communication apparatus also includes infrastructure facilities, such as base stations, access points, and any other apparatus, device, or system that communicates with or controls the various apparatuses listed above, but are not limited to these.

[0274] An access point according to one embodiment of the present disclosure includes a control circuit that generates parameters related to uplink transmission power control based on information related to transmission power control received from other access points, and a transmission circuit that transmits a control signal including the parameters.

[0275] In one embodiment of the present disclosure, the parameters include information regarding downlink transmission power determined for each of a plurality of terminals in accordance with a type of uplink communication control.

[0276] In one embodiment of the present disclosure, the control signal includes common information including information common to the multiple terminals and terminal-specific information individual to the multiple terminals, the common information including a value common to the multiple terminals regarding the downlink transmission power, and the terminal-specific information including an offset value relative to the common value.

[0277] In one embodiment of the present disclosure, the control signal includes common information including information common to the plurality of terminals and terminal-specific information individual to the plurality of terminals, the common information including information related to the transmission power of the plurality of downlinks, and the terminal-specific information including an index associated with the information related to the transmission power of the plurality of downlinks.

[0278] In one embodiment of the present disclosure, information regarding downlink transmission power for each access point related to uplink communication control is included.

[0279] In one embodiment of the present disclosure, the parameter includes information regarding the target received signal strength of the access point in uplink communication control, and the bit size corresponding to the information regarding the target received signal strength differs between a case where the uplink communication control is performed in coordination between the access point and the other access point and a case where the uplink communication control is not performed in coordination between the access point and the other access point.

[0280] In one embodiment of the present disclosure, the parameter includes an index associated with a candidate value of a target received signal strength of the access point in uplink communication control, and the difference between the target received signal strengths associated with a first index and a second index differs between a case where the uplink communication control is performed in coordination between the access point and the other access point and a case where the uplink communication control is not performed in coordination between the access point and the other access point.

[0281] In one embodiment of the present disclosure, the control circuit determines the format of the control signal to be a first format when the uplink communication control is to be coordinated between the base stations, based on information regarding the coordination of the uplink communication control, and determines the format of the control signal to be a second format when the uplink communication control is not to be coordinated between the base stations.

[0282] In one embodiment of the present disclosure, the information regarding the coordination of uplink communication control includes flag information indicating whether or not the coordination is to be performed.

[0283] In one embodiment of the present disclosure, the flag information is included in any one of common information including information common to a plurality of terminals, a signal field in a data unit including the control signal, and a beacon.

[0284] In one embodiment of the present disclosure, the information regarding the coordination of the uplink communication control includes information regarding the type of the control signal, and the control circuit sets the first format when the type of the control signal corresponds to the coordination.

[0285] In one embodiment of the present disclosure, the control circuit generates the control signal for each of the access points.

[0286] A terminal according to one embodiment of the present disclosure includes a receiving circuit that receives a control signal including parameters related to uplink transmission power control generated based on information related to transmission power control received from another access point, and a control circuit that controls the uplink transmission power based on the parameters.

[0287] In a communication method according to one embodiment of the present disclosure, an access point generates parameters related to uplink transmission power control based on information related to transmission power control received from another access point, and transmits a control signal including the parameters.

[0288] In a communication method according to one embodiment of the present disclosure, a terminal receives a control signal including parameters related to uplink transmission power control generated based on information related to transmission power control received from another access point, and controls the uplink transmission power based on the parameters.

[0289] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2020-090745, filed on May 25, 2020, are incorporated herein by reference in their entirety.

[0290] One embodiment of the present disclosure is useful in wireless communication systems.

[0291] 100 AP 101 Setting unit 102 STA-directed control signal generating unit 103 AP-directed control signal generating unit 104, 205 Transmission signal generating unit 105, 201 Radio transmitting / receiving unit 106, 202 Received signal demodulation / decoding unit 200 STA 203 Transmission power calculating unit 204 Response signal generating unit

Claims

1. An access point comprising: a control circuit that generates parameters related to uplink transmission power control based on information related to transmission power control received from other access points; and a transmission circuit that transmits a control signal including the parameters.

2. The access point according to claim 1, wherein the parameters include information related to the transmission power of the downlink determined corresponding to the type of uplink communication control for each of a plurality of terminals.

3. The access point according to claim 2, wherein the control signal includes common information including information common to the plurality of terminals and terminal-specific information specific to the plurality of terminals, the common information includes a value common to the plurality of terminals related to the transmission power of the downlink, and the terminal-specific information includes an offset value with respect to the common value.

4. The access point according to claim 2, wherein the control signal includes common information including information common to the plurality of terminals and terminal-specific information specific to the plurality of terminals, the common information includes information related to the transmission power of a plurality of the downlinks, and the terminal-specific information includes an index associated with the information related to the transmission power of the plurality of downlinks.

5. The access point according to claim 1, wherein the parameters include information related to the transmission power of the downlink for each access point related to uplink communication control.

6. The access point according to claim 1, wherein the parameters include information related to the target received signal strength of the access point in uplink communication control, and the bit size corresponding to the information related to the target received signal strength is different between a case where uplink communication control is coordinated between the access point and other access points and a case where uplink communication control is not coordinated between the access point and other access points.

7. The parameter includes an index associated with a candidate value of a target reception signal strength of the access point in uplink communication control, and a difference between the target reception signal strengths associated with the first index and the second index respectively is different between a case where the uplink communication control is coordinated between the access point and the other access point and a case where the uplink communication control is not coordinated between the access point and the other access point. The access point according to claim 1.

8. The control circuit determines that the format of the control signal is a first format when performing the uplink communication control coordinated between the access point and the other access point based on information regarding coordination of the uplink communication control, and determines that the format of the control signal is a second format when not performing the uplink communication control coordinated between the access point and the other access point. The access point according to claim 1.

9. The information regarding coordination of the uplink communication control includes flag information indicating whether to perform the coordination. The access point according to claim 8.

10. The flag information is included in any one of common information including information common to a plurality of terminals, a signal field in a data unit including the control signal, and a beacon. The access point according to claim 9.

11. The information regarding coordination of the uplink communication control includes information regarding the type of the control signal, and the control circuit sets the first format when the type of the control signal is a type corresponding to the coordination. The access point according to claim 8.

12. The control circuit generates the control signal for each access point. The access point according to claim 1.

13. A receiving circuit that receives a control signal including a parameter related to uplink transmission power control generated based on information related to transmission power control received from another access point, and a control circuit that controls the transmission power of the uplink based on the parameter. A terminal comprising:

14. A communication method in which an access point generates parameters related to uplink transmission power control based on information related to transmission power control received from another access point, and transmits a control signal including the parameters.

15. A communication method in which a terminal receives a control signal including parameters related to uplink transmission power control generated based on information related to transmission power control received from another access point, and controls the transmission power of the uplink based on the parameters.

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