Communication device, communication method, and program

Abstract

Provided is a communication device capable of transmitting, to another communication device, a wireless frame compliant with one or more standards included in the IEEE 802.11 standard series, wherein at least part of a first association between each of a plurality of MCSs defined in a first standard included in the IEEE 802.11 standards and an MCS index that uniquely identifies each MCS differs from a second association defined in a second standard which was standardized prior to the first standard. The communication device has: a generation means for generating a wireless frame including a preamble signal and a data signal, in which the preamble signal includes first information capable of identifying which of the first association and the second association should be used by another communication device to identify the MCS from the MCS index, and second information indicating the MCS index corresponding to the MCS used for generating the data signal, and the data signal is generated by using the MCS indicated by the first information and the second information; and a transmission means for transmitting, to the other communication device, the wireless frame generated by the generation means. The generation means generates the wireless frame in which the second information is included in a U-SIG field of the preamble signal.

Description

Communication Device, Communication Method, and Program

[0001] The present disclosure relates to data communication technology in a communication device that communicates using one Modulation and Coding Scheme (MCS) included in a plurality of MCSs.

[0002] In recent years, with the increase in the amount of data to be communicated, the development of communication technologies such as wireless LAN (Local Area Network) has been promoted. As the main communication standards for wireless LAN, the IEEE (Institute of Electrical and Electronic Engineers) 802.11 standard series is known. The IEEE 802.11 standard series includes IEEE 802.11a / b / g / n / ac / ax / be standards, etc. For further improvement of communication reliability, the development of the IEEE 802.11bn standard is in progress as a successor standard to the IEEE 802.11be standard. In the IEEE 802.11 WG (Working Group) that formulates the IEEE 802.11bn standard, in the UHR SG, the goals and scope of consideration of this standard are determined, and in TGbn, the detailed technical content to be included in this standard is planned to be defined. Note that UHR SG is an abbreviation for Ultra High Reliability Study Group. Also, TGbn is an abbreviation for Task Group bn.

[0003] In the current latest standard, the IEEE 802.11ax standard (Non-Patent Document 1), as the MCS with the maximum data rate, a combination of a modulation method of 1024-QAM and a coding rate of 5 / 6 is defined. On the other hand, in the formulation of the IEEE 802.11bn standard, studies are being conducted to diversify the combinations of Modulation and Coding Scheme (MCS) that can be used by communication devices.

[0004] IEEE, "Wireless LAN MAC and PHY Specifications Amendment 1: Enhancements for High-Efficiency WLAN"

[0005] This disclosure provides a technology for appropriately notifying the other party's communication device of the MCS that a communication device will use for transmission in a communication system that can use multiple types of MCS.

[0006] A communication device according to one aspect of the present disclosure is a communication device capable of transmitting wireless frames conforming to one or more standards included in the IEEE 802.11 standard series to another communication device, wherein the communication device is capable of transmitting a plurality of Modulation and Codings as defined in a first standard included in the standard series. At least a portion of the first correspondence between each Scheme (MCS) and an MCS index that uniquely identifies the MCS differs from the second correspondence defined in a second standard that was standardized before the first standard. The communication device has generating means for generating a wireless frame which includes a preamble signal and a data signal, the preamble signal including first information that allows the other communication device to determine whether to use the first correspondence or the second correspondence to identify the MCS from the MCS index, and second information indicating the MCS index corresponding to the MCS used to generate the data signal; and a data signal generated using the MCS indicated by the first information and the second information; and transmitting means for transmitting the wireless frame generated by the generating means to the other communication device, wherein the generating means generates the wireless frame which includes the first information in the Universal Signal (U-SIG) field of the preamble signal.

[0007] According to this disclosure, in a communication system that can use multiple types of MCS, the communication device will be able to appropriately notify the other party's communication device of the MCS it will use for transmission.

[0008] Other features and advantages of this disclosure will become apparent from the following description with reference to the accompanying drawings. In the accompanying drawings, the same or similar components are given the same reference numeral.

[0009] The attached drawings are included in the specification and constitute part thereof, illustrating embodiments of the present disclosure and are used together with the description to explain the principles of the present disclosure. Figure 1 is a diagram showing an example configuration of a wireless communication system. Figure 2 is a diagram showing an example hardware configuration of a communication device. Figure 3 is a diagram showing an example functional configuration of a transmitting communication device. Figure 4 is a diagram showing an example functional configuration of a receiving communication device. Figure 5 is a diagram showing an example processing flow executed by a communication device in the transmission processing of a PPDU. Figure 6 is a diagram showing an example processing flow executed by a communication device in the reception processing of a PPDU. Figure 7A is a diagram showing an example frame format conforming to the second standard. Figure 7B is a diagram showing an example frame format conforming to the second standard. Figure 8A is a diagram showing an example configuration of an EHT-SIG. Figure 8B is a diagram showing an example configuration of an EHT-SIG. Figure 8C is a diagram showing an example configuration of an EHT-SIG. Figure 9A is a diagram showing an example configuration of an EHT-SIG. Figure 9B is a diagram showing an example configuration of an EHT-SIG. Figure 9C is a diagram showing an example configuration of an EHT-SIG. Figure 10 is a diagram showing an example configuration of a Trigger frame. Figure 11A shows an example of the configuration of the User Info field. Figure 11B shows an example of the configuration of the User Info field. Figure 11C shows an example of the configuration of the User Info field. Figure 12A shows an example of a frame format conforming to the first standard. Figure 12B shows an example of a frame format conforming to the first standard. Figure 13 shows an example of a sequence executed between AP and STA. Figure 14 shows an example of a sequence executed between AP and STA. Figure 15 shows an example of the configuration of the MCS table. Figure 16A shows an example of the configuration of U-SIG. Figure 16B shows an example of the configuration of U-SIG. Figure 17A shows an example of the configuration of the Common field. Figure 17B shows an example of the configuration of the Common field. Figure 18 shows an example of the configuration of User encoding block. Figure 19 shows an example of the configuration of the User field. Figure 20 shows an example of the configuration of the User field. Figure 21 shows an example of the configuration of the Common field. Figure 22 shows an example of the User field configuration. Figure 23 shows an example of the Common field configuration.Figure 24A shows an example of the U-SIG configuration. Figure 24B shows an example of the U-SIG configuration. Figure 25 shows an example of the User field configuration. Figure 26 shows an example of the User field configuration. Figure 27 shows an example of the MCS table configuration. Figure 28 shows an example of the MCS table configuration. Figure 29 shows an example of the MCS table configuration. Figure 30 shows an example of the MCS table configuration.

[0010] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the scope of the claims. While the embodiments describe multiple features, not all of these features are necessary, and the features may be combined in any way. Furthermore, in the attached drawings, identical or similar configurations are given the same reference numerals, and redundant descriptions are omitted.

[0011] (System Configuration) Figure 1 shows an example of the configuration of a wireless communication system according to this embodiment. The wireless communication system includes, for example, an access point (AP) 101 and stations (STA) 111 and STA 112. STA 111 and STA 112 are sometimes referred to as STA 110 without distinction. Also, AP 101 and STA 110 are sometimes referred to as communication device 100 without distinction. AP 101 and STA 110 are communication devices capable of performing wireless communication in accordance with the IEEE 802.11 standard series. For example, AP 101 and STA 110 are configured to be able to transmit and receive wireless frames in accordance with the IEEE 802.11 standard series. IEEE is an abbreviation for Institute of Electrical and Electronics Engineers. Figure 1 shows a configuration in which STA 111 and STA 112 participate in network 121 established by AP 101. Network 121 may also be called a Basic Service Set (BSS). In network 121 in Figure 1, a configuration with one AP 101 and two STAs is shown, but for example, there may be multiple APs, and there may be one or more STAs. In that case, each STA may be connected to one AP, or one STA may be connected to multiple APs.

[0012] In this embodiment, the communication device 100 is configured to execute a communication method compliant with the IEEE 802.11bn standard. The IEEE 802.11bn standard is the successor to the IEEE 802.11be standard, which aims for a maximum transmission speed of 46.08 Gbps (Gigabits per second). The main features of the IEEE 802.11bn standard are that it has functions that realize highly reliable communication, low latency communication, and improved throughput when communication traffic is congested. The wireless frame used in a communication method compliant with this standard may be called a UHR (Ultra High Reliability) PPDU. PPDU is an abbreviation for PLCP Protocol Data Unit, and PLCP is an abbreviation for Physical Layer Convergence Protocol. Note that the names UHR and IEEE 802.11bn may be changed to different names once the standard is finalized. Also note that this specification and the claims attached herein are applicable to communication devices using all successor standards that are successor standards to IEEE 802.11be. Furthermore, the communication device 100 may correspond to at least one of the legacy standards that were standardized before the IEEE 802.11bn standard. Legacy standards include, for example, the IEEE 802.11a / b / g / n / ac / ax / be standards. For example, a wireless frame used in a communication method compliant with the IEEE 802.11be standard may be called an EHT (Extremely High Throughput) PPDU. If the communication device 100 supports both the IEEE 802.11be standard and the IEEE 802.11bn standard, the communication device 100 can support both communication using UHR PPDUs and communication using EHT PPDUs. The communication device 100 may also support other communication standards such as Bluetooth®, NFC, UWB, ZigBee, and MBOA. UWB is an abbreviation for Ultra Wide Band, and MBOA is an abbreviation for Multi Band OFDM Alliance. Furthermore, NFC is an abbreviation for Near Field Community.UWB includes wireless USB, wireless 1394, WiNET, etc. The communication device 100 may also support communication standards such as wired LAN. AP101 is, for example, a wireless LAN router or a personal computer (PC), but is not limited to these. AP101 may be an information processing device such as a wireless chip capable of performing wireless communication compliant with legacy standards, IEEE 802.11bn standards, and their successor standards. STA110 is, for example, a camera, tablet, smartphone, PC, mobile phone, video camera, headset, smart glasses, HMD (head-mounted display), and other wearable devices, but is not limited to these. STA110 may be an information processing device such as a wireless chip capable of performing wireless communication supporting PPDU transmission and reception compliant with legacy standards, IEEE 802.11bn standards, and their successor standards. In this case, the wireless chip can be configured to perform various controls using internal hardware circuits. Furthermore, the wireless chip can be configured to execute various processes through the cooperation of processors such as ASIP, memory, and hardware circuits within the chip. ASIP is an abbreviation for Application-specific instruction set processor.

[0013] The communication device 100 can communicate using radio signals in frequency bands such as the 2.4 GHz band, 3.6 GHz band, 5 GHz band, 6 GHz band, and millimeter wave bands such as the 45 GHz band and 60 GHz band. The frequency bands used by the communication device 100 are not limited to these, and may include, for example, the Sub1 GHz band. Furthermore, the communication device 100 can communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, 540 MHz, 640 MHz, 1080 MHz, and 2160 MHz. The bandwidths used by the communication device 100 are not limited to these, and may include, for example, 240 MHz or 4 MHz. Note that the IEEE 802.11 standard series specifies frequency channels using a bandwidth of 20 MHz as basic channels in frequency bands such as the 2.4 GHz, 5 GHz, and 6 GHz bands. Furthermore, this standard defines multiple available channels in each of the 2.4 GHz, 5 GHz, and 6 GHz frequency bands.

[0014] Some standards included in the IEEE 802.11 standard series specify combinations of modulation schemes and coding rates that can be used between communication devices. A combination of modulation scheme and coding rate can be called a Modulation and Coding Scheme (MCS). For example, the IEEE 802.11be standard considers making 15 combinations of MCS, as shown in Figure 15, usable. For each MCS, which is composed of a combination of one modulation scheme and one coding rate, an index called an MCS index is associated with it to uniquely identify that MCS. For example, for an MCS with the modulation scheme 4096-QAM and a coding rate of 5 / 6, the MCS index value associated with it is 13. QAM is an abbreviation for Quadrature Amplitude Modulation. In this embodiment, the correspondence between MCS and MCS index as shown in Figure 15 will be referred to as the MCS table.

[0015] When the communication device 100 transmits data to the other party's communication device, it selects one MCS from among several MCSs specified in the standard to which it belongs. The communication device 100 generates a data signal to be transmitted to the other party's communication device using the selected MCS and transmits a PPDU containing this data signal. The communication device 100 uses a predetermined area included in the PPDU's preamble signal (preamble) to notify the other party's communication device of the MCS used by the communication device to generate the data signal. For example, in the IEEE 802.11be standard, a 4-bit EHT SIG field is planned to be provided in the preamble as a predetermined area for notifying the receiving communication device of the MCS used by the transmitting communication device. When the communication device 100 notifies the other party's communication device of the MCS used for transmission, it uses the MCS index associated with that MCS. For example, in the case of an EHT PPDU compliant with the IEEE 802.11be standard, the MCS index associated with the MCS used for transmission is set in the EHT SIG field. The receiving communication device can identify the MCS used by the transmitter based on the MCS index set in the EHT SIG field of the preamble of the received EHT PPDU. The receiving communication device obtains the data contained in the PPDU by performing demodulation based on the identified MCS.

[0016] On the other hand, the IEEE 802.11bn standard is considering diversifying the MCS (Multimodulation Control System) that communication devices can use. For example, MCS combinations of modulation schemes and coding rates of 2 / 3 for QPSK (Quadrature Phase Shift Keying), 16QAM (Quadrature Amplitude Modulation), and 256QAM may be added. Additionally, an MCS combination of the 16QAM modulation scheme and coding rates of 5 / 6 may be added. These MCS are not used in legacy standards. The addition of these MCS will increase the types of MCS that can be used by STAs located in the intermediate region between AP101 and the edge of the BSS, such as STA112 in Figure 1. This may improve the overall throughput of the BSS. If these four MCS are added, it will be necessary to assign a new MCS index to each MCS. However, as mentioned above, in the IEEE 802.11be standard, the EHT SIG field for notifying the other party's communication device of the MCS is 4 bits, so it is not possible to assign new MCS indices to these added MCSs. For example, the decimal numbers that can be represented with 4 bits are in the range of 0 to 15, but as shown in Figure 15, there is only one index in this range that is not used: 14. Therefore, there is insufficient number of indices to assign new indices to the four additional MCSs. Furthermore, the mapping between MCSs and MCS indices in the IEEE 802.11be standard is such that the value of the MCS index increases as the modulation level and coding rate increase. Therefore, if the four MCSs mentioned above are added, there is a possibility that the data may not be correctly received and processed due to differences in the interpretation of the MCS index values ​​defined in the respective standards between the transmitting and receiving communication devices. For example, suppose that in the IEEE 802.11bn standard and the IEEE 802.11be standard, different MCSs are associated with the same MCS index.In this case, if the transmitting communication device uses the first MCS table of the IEEE 802.11bn standard for transmission processing, and the receiving communication device uses the second MCS table of the IEEE 802.11be standard for reception processing, the reception processing may not be performed correctly.

[0017] In light of these circumstances, the transmitting communication device 100 in this embodiment includes predetermined information for identifying the MCS from the MCS index included in the wireless frame in the preamble signal of the wireless frame. The predetermined information for identifying the MCS from the MCS index includes first information and second information. The first information is information that can identify whether to use a first MCS table or a second MCS table to identify the MCS from the MCS index. The second information is information that indicates the MCS index corresponding to the MCS used to generate the data signal included in the wireless frame. The first information may be included in the Universal Signal (U-SIG) field in the preamble. On the other hand, the receiving communication device 100 in this embodiment uses the first information and the second information included in the preamble signal of the received wireless frame to identify the MCS from the MCS index. For example, the receiving communication device 100 determines, based on the first information, whether to use the first MCS table or the second MCS table to identify the MCS from the MCS index. The receiving communication device 100 then uses the identified MCS table to identify the MCS from the MCS index indicated by the second information. Finally, the receiving communication device 100 demodulates the data signal based on the identified MCS. This configuration makes it possible to match the MCS tables used to identify the MCS from the MCS index between the transmitting communication device 100 and the receiving communication device 100. As a result, even if the standards used by the transmitting communication device 100 and the receiving communication device 100 include multiple standards in which at least part of the MCS tables specified in the standards differ, the demodulation process of the wireless frame will be performed appropriately.

[0018] The first piece of information may be information indicating the standard to which the transmitted wireless frame conforms. If the MCS tables specified for each standard are different, the receiving communication device 100 can identify the MCS table it should use by knowing the standard to which the wireless frame conforms. The standard to which the wireless frame conforms may be indicated by the value of the PHY Version Identifier field in the U-SIG field. For example, if the wireless frame conforms to the first standard (IEEE 802.11bn standard), the PHY Version Identifier field may be set to a value greater than 0. Also, if the wireless frame conforms to the second standard (IEEE 802.11be standard), the PHY Version Identifier field may be set to a value of 0.

[0019] The first MCS table may include MCS not included in the second MCS table. For example, the first MCS table may include a first MCS using QPSK and a coding rate of 2 / 3, a second MCS using 16QAM and a coding rate of 2 / 3, a third MCS using 16QAM and a coding rate of 5 / 6, a fourth MCS using 64QAM and a coding rate of 2 / 3, and so on. For this reason, the MCS index used in the first MCS table may be represented by 5 bits. Furthermore, the first MCS table may be configured to include the first to fourth MCS, etc., and to assign smaller MCS index values ​​to MCS with lower data rates. In addition, the first MCS table may be configured to assign MCS indexes not used in the second MCS table to the first to fourth MCS, etc. An example of the configuration and processing of a communication device 100 operating in this manner will be described below.

[0020] (Device Configuration) Figure 2 shows an example of the hardware configuration of the communication device 100 of this embodiment. As an example of its hardware configuration, the communication device 100 has, for example, a storage unit 201, a control unit 202, a function unit 203, an input unit 204, an output unit 205, a communication unit 206, and an antenna 207. The communication device 100 may have multiple antennas.

[0021] The storage unit 201 is composed of one or more memories, including ROM and RAM, and may store control programs for various operations performed by each functional unit constituting the communication device 100, as well as various information such as parameters for communication. ROM and RAM are abbreviations for Read Only Memory and Random Access Memory, respectively. In addition to memories such as ROM and RAM, the storage unit 201 may also be composed of storage media such as flexible disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, and DVDs.

[0022] The control unit 202 is composed of one or more processors, such as a CPU and an MPU, and controls the entire communication device 100 by executing a control program stored in the storage unit 201. Alternatively, the control unit 202 may control the entire communication device 100 through cooperation between the control program stored in the storage unit 201 and the OS (Operating System). CPU and MPU are abbreviations for Central Processing Unit and Micro Processing Unit, respectively. If the control unit 202 has multiple processors that can be implemented as a multi-core processor, the entire communication device 100 may be controlled by these multiple processors.

[0023] Furthermore, the control unit 202 controls the functional unit 203 to perform predetermined processes such as communication, imaging, printing, and projection. The functional unit 203 is hardware that enables the communication device 100 to perform the predetermined processes described above. For example, if the device is a camera, the functional unit 203 is the imaging unit and performs imaging processing. Also, for example, if the device is a printer, the functional unit 203 is the printing unit and performs printing processing. Also, for example, if the device is a projector, the functional unit 203 is the projection unit and performs projection processing.

[0024] The input unit 204 receives various operations from the user. The output unit 205 outputs various information to the user via a monitor screen or speaker. The output from the output unit 205 may be a display on the monitor screen, audio output via a speaker, vibration output, etc. The input unit 204 and the output unit 205 may both be implemented in a single module, such as a touch panel. The input unit 204 and the output unit 205 may be integrated with the communication device 100, or they may be separate devices.

[0025] The communication unit 206 controls wireless communication compliant with the IEEE 802.11bn standard. In addition to the IEEE 802.11bn standard, the communication unit 206 may also control wireless communication compliant with other IEEE 802.11 standard series, such as legacy standards. For example, the communication unit 206 may support both wireless communication compliant with the IEEE 802.11be standard and wireless communication compliant with the IEEE 802.11bn standard. The communication unit 206 controls the antenna 207 to transmit and receive signals for wireless communication generated by the control unit 202. The communication unit 206 is a so-called wireless chip and may itself have one or more processors and memory. If the communication device 100 supports other wireless communication standards such as NFC standards and Bluetooth standards, or wired communication such as wired LAN, in addition to the IEEE 802.11bn standard, the communication unit 206 may also control communication compliant with these communication standards. Furthermore, if the communication device 100 can perform wireless communication compliant with multiple communication standards, the communication device 100 may be configured to have separate communication units and antennas corresponding to each communication standard. The communication device 100 communicates data with the other party's communication device via the communication unit 206. The antenna 207 may be configured separately from the communication unit 206, or it may be configured as a single module together with the communication unit 206.

[0026] Antenna 207 is an antenna capable of communication in millimeter waves such as the 2.4 GHz band, 5 GHz band, 6 GHz band, 45 GHz band, and 60 GHz band, for example. Figure 2 shows a configuration in which the communication device 100 has two antennas 207, but the communication device 100 may have one or more antennas, or one or more antennas for each frequency band that the device can use. Also, if the communication device 100 has multiple antennas, the communication device 100 may have a communication unit 206 for each antenna. Antenna 207 may be physically composed of two or more antennas in order to realize (Multi-Input and Multi-Output) transmission and reception.

[0027] (Functional Configuration) Figure 3 shows an example of the functional configuration of the transmitting communication device 100. The functional configuration in this embodiment is an example of a functional configuration realized by, for example, one or more processors executing programs stored in one or more memories. The communication device 100 may be configured to include an MCS management unit 301, a communication control unit 302, a frame generation unit 303, a frame transmission unit 304, and a frame reception unit 305.

[0028] The MCS management unit 301 manages the MCS tables. For example, the MCS management unit 301 maintains MCS tables that correspond to the MCS and MCS index mappings specified in each standard to which the communication device 100 is compatible. When an MCS table is associated with a standard, the MCS management unit 301 can manage multiple MCS tables based on the standard to which the communication device 100 is compatible. For example, the MCS management unit 301 can maintain and manage a first MCS table specified in the IEEE 802.11bn standard and a second MCS table specified in the IEEE 802.11be standard. Furthermore, if multiple mappings between MCS and MCS indexes are specified in a single standard, the MCS management unit 301 can maintain multiple MCS tables corresponding to each mapping.

[0029] The communication control unit 302 performs control for communicating with the other party's communication device. For example, the communication control unit 302 may determine the type of PPDU to be used for communication and the MCS for generating data signals. The communication control unit 302 may identify the standards supported by the other party's communication device and select the PPDU to be used for communication according to the identified standards. For example, the communication control unit 302 in AP101 may identify the standards supported by STA111 and STA112 and select the PPDU to be used according to the data destination. As an example, if STA111 supports the first and second standards, and STA112 supports the second standard, AP101 may select the second standard in order to transmit data to STA111 and STA112 in parallel. The communication control unit 302 may also identify the MCS available to the other party's communication device and select the MCS to be used for communication according to the identified MCS. For example, the communication control unit 302 in AP101 can identify multiple MCSs that can be used by STA110 based on the standards that STA110 supports, and select an appropriate MCS from among them according to the channel conditions.

[0030] The frame generation unit 303 generates a PPDU. For example, the frame generation unit 303 generates a PPDU using the type of PPDU and MCS selected by the communication control unit 302. If the communication control unit 302 selects a type of PPDU that the other party's communication device should transmit based on the corresponding standard, the frame generation unit 303 can configure a PPDU corresponding to that type. For example, if the communication control unit 302 selects to transmit using a UHR MU PPDU, the frame generation unit 303 generates a preamble signal and data signals according to the configuration of the UHR MU PPDU to configure the PPDU. The frame generation unit 303 can generate data signals using the MCS selected by the communication control unit 302. The frame generation unit 303 also sets the MCS index corresponding to the MCS used to generate the data signals in the preamble of the PPDU. When generating a UHR MU PPDU, the frame generation unit 303 may use the first MCS table to identify the MCS index corresponding to the MCS used to generate the data signal and set it in the preamble. When generating an EHT MU PPDU, the frame generation unit 303 may use the second MCS table to identify the MCS index corresponding to the MCS used to generate the data signal and set it in the preamble. The frame generation unit 303 also sets information in the preamble that identifies the MCS table that the other party's communication device should use. For example, if the frame generation unit 303 has identification information that uniquely identifies the MCS table, it may set that identification information in the preamble. Furthermore, if a standard and an MCS table are associated, the frame generation unit 303 may notify the other party's communication device of information indicating the standard to which the generated PPDU conforms, as information that identifies the MCS table that the other party's communication device should use.

[0031] Furthermore, the frame generation unit 303 of STA110 can generate a PPDU based on the information contained in the Trigger frame received from AP101. In this case, the frame generation unit 303 can generate a PPDU according to the type of PPDU indicated by the Trigger frame. The frame generation unit 303 can also generate a data signal using an MCS identified from the Trigger frame. In this case, the frame generation unit 303 uses the MCS table to be used indicated by the Trigger frame to identify the MCS to be used for generating the data signal from the MCS index contained in the Trigger frame.

[0032] The frame transmission unit 304 transmits the PPDU generated by the frame generation unit 303. The frame reception unit 305 receives frames transmitted by the other party's communication device. For example, the frame reception unit 305 receives an acknowledgment for the PPDU transmitted by the frame transmission unit 304. The frame reception unit 305 of STA 110 can also receive Trigger frames from AP 101.

[0033] Figure 4 shows an example of the functional configuration of the receiving communication device 100. The functional configuration in this embodiment is an example of a functional configuration realized by, for example, one or more processors executing a program stored in one or more memories. The communication device 100 may include an MCS management unit 401, a frame analysis unit 402, a data demodulation unit 403, a frame receiving unit 404, and a frame transmission unit 405. AP101 may further include a trigger generation unit 406. Note that the MCS management unit 401 operates in the same way as the MCS management unit 301, so its explanation is omitted.

[0034] The frame analysis unit 402 analyzes the PPDU received from the other party's communication device. For example, the frame analysis unit 402 analyzes the preamble included in the PPDU and obtains information for acquiring data from the data signal. By analyzing the preamble, the frame analysis unit 402 can obtain information indicating the standard to which the PPDU conforms. The frame analysis unit 402 can identify the configuration of the PPDU based on the standard to which the PPDU conforms. Furthermore, based on the identified PPDU configuration, the frame analysis unit 402 can obtain information indicating the MCS index corresponding to the MCS used to generate the data, information identifying the MCS table to be used to identify the MCS from the MCS index, and so on. When a standard is associated with an MCS table, the frame analysis unit 402 can identify the MCS table to be used based on the information indicating the standard to which the PPDU conforms. Using the identified MCS table, the frame analysis unit 402 can identify the MCS used to generate the data from the MCS index included in the PPDU.

[0035] The data demodulation unit 403 demodulates the data signal to acquire data. For example, the data demodulation unit 403 demodulates the data signal included in the PPDU based on the MCS identified by the frame analysis unit 402.

[0036] The frame receiving unit 404 receives the PPDU from the other party's communication device. The frame transmitting unit 405 transmits a frame to the other party's communication device. For example, the frame transmitting unit 405 transmits an acknowledgment for the received PPDU to the other party's communication device. In addition, the frame transmitting unit 405 in AP 101 may transmit a Trigger frame to STA 110.

[0037] The Trigger generation unit 406 generates a Trigger frame. For example, the Trigger generation unit 406 of AP101 can generate a Trigger frame when multiple STA110s are to transmit data in parallel via multi-user transmission. The Trigger generation unit 406 can set information in the Trigger frame indicating the type of PPDU that STA110 should use for communication and the MCS that STA110 should use for generating data signals. For example, the Trigger generation unit 406 can select the type of PPDU that STA110 should use based on the standard that STA110 supports. As an example, if STA111 supports the first and second standards, and STA112 supports the second standard, AP101 can select the second standard in order to transmit data in parallel to STA111 and STA112. Furthermore, the Trigger generation unit 406 can identify the MCS available to the other party's communication device and select the MCS to be used for generating the data signal according to the identified MCS. For example, the Trigger generation unit 406 can identify multiple MCS available to STA110 based on the standards that STA110 supports, and select an appropriate MCS from among them according to the channel conditions. The Trigger generation unit 406 can set in the Trigger frame information that identifies the MCS table to be used by the other party's communication device and an MCS index corresponding to the MCS to be used for generating the data signal.

[0038] (Examples of processes performed by the communication device during transmission) Below, several examples of the processing flow performed by the communication device 100 in this embodiment will be described. First, the processing flow performed by the communication device 100 when performing transmission processing will be described. Since both AP101 and STA110 can transmit data, the communication device 100 in this example may be either AP101 or STA110. In this example, the communication device 100 is capable of performing communication compliant with a first standard and communication compliant with a second standard included in the IEEE 802.11 standard series. That is, the communication device 100 can perform PPDU transmission processing compliant with the first standard and PPDU transmission processing compliant with the second standard. For example, the first standard may be the IEEE 802.11bn standard or its successor standard, and in this embodiment, it is the IEEE 802.11bn standard. Furthermore, the second standard may be a legacy standard for the IEEE 802.11bn standard, and in this embodiment, it is the IEEE 802.11be standard. Figure 5 shows an example of a processing flow executed when the communication device 100 performs PPDU transmission processing. This processing flow may be started, for example, based on the communication device 100 detecting that data has been input into the transmission buffer of the communication device 100. First, the communication device 100 determines the type of PPDU to be used for transmission. For example, the communication device 100 determines whether to use a PPDU conforming to the first standard or a PPDU conforming to the second standard for transmission (S501). For example, the communication device 100 may determine the type of PPDU to be used for transmission based on the standard supported by the other party's communication device. As an example, if the other party's communication device supports the first standard but not the second standard, the communication device 100 may determine to use a PPDU conforming to the first standard. Furthermore, if the other party's communication device does not support the first standard but supports the second standard, the communication device 100 may determine that it will use a PPDU compliant with the second standard. If the other party's communication device supports both the first and second standards, the communication device 100 may determine that it will use a PPDU compliant with the first standard. This may enable communication using relatively advanced functions.On the other hand, if the other party's communication device supports both the first and second standards, the communication device 100 may determine that it will use a PPDU compliant with the second standard. This makes it easier for peripheral terminals supporting legacy standards to understand the communication status, thus potentially reducing interference. Furthermore, the communication device 100 may identify the standards supported by the other party's communication device during the procedure for establishing a connection with the other party's communication device. For example, the communication device 100 may identify the standards supported by the other party's communication device by acquiring capability information that includes information that allows for the identification of the standards supported by the other party's communication device. As an example, the communication device 100 may determine that the other party's communication device complies with the IEEE 802.11be standard by receiving a frame containing an EHT Capabilities element from the other party's communication device. Furthermore, the communication device 100 can determine that the other party's communication device complies with the IEEE 802.11bn standard by receiving a frame containing the UHR Capabilities element from the other party's communication device. Note that both the communication device 100 and the other party's communication device may support three or more standards included in the IEEE 802.11 standard series. In this case, the communication device 100 can perform transmission processing using a PPDU that complies with one of the standards supported by both its own device and the other party's communication device. The following explanation uses examples corresponding to the first and second standards, but the communication device 100 can operate similarly even when it supports three or more standards.

[0039] If the communication device 100 determines that it will use a PPDU conforming to the first standard (YES in S501), it may generate a data signal using the MCS defined in the first standard and transmit the PPDU containing the generated data signal. At this time, the communication device 100 sets information in a first area within the PPDU to identify the MCS from the MCS index included in the PPDU (S502). For example, the communication device 100 sets information indicating that the first MCS table defined in the first standard should be used. If each MCS table usable between the communication device 100 and the other party's communication device is assigned a unique identifier, the communication device 100 may set that identifier in the first area. Furthermore, if the MCS tables defined for each standard are different, the communication device 100 may use information indicating the standard to which the PPDU conforms as information that can identify the MCS table. For example, if the PPDU format used differs for each standard, a field for identifying the PPDU format may be used as a first area for identifying the MCS table that the receiving communication device 100 should use. The communication device 100 also sets an MCS index in a second area within the PPDU that corresponds to the MCS used by the device to generate the data signal (S503). The communication device 100 uses an MCS index based on a first MCS table specified in the first standard as the MCS index set in the second area of ​​the PPDU. The communication device 100 may include the first and second areas within the PPDU preamble. If the first standard is the IEEE 802.11bn standard, the second area of ​​the PPDU may be a 5-bit field. The communication device 100 transmits the generated PPDU (S504).

[0040] On the other hand, if the communication device 100 determines that it will use a PPDU conforming to the second standard (NO in S501), it may generate a data signal using the MCS defined in the second standard and transmit the PPDU containing the generated data signal. At this time, the communication device 100 sets information in a first area of ​​the PPDU indicating that the second MCS table defined in the second standard should be used to identify the MCS from the MCS index included in this PPDU (S505). For example, the communication device 100 sets a value in the first area indicating that this PPDU conforms to the second standard. The communication device 100 also sets an MCS index in a second area of ​​the PPDU that corresponds to the MCS used by the device to generate the data signal (S506). The communication device 100 sets an MCS index based on the second MCS table defined in the second standard as the MCS index set in the second area of ​​the PPDU. If the second standard is the IEEE 802.11be standard, the second area of ​​the PPDU may be a 4-bit field. The communication device 100 transmits the generated PPDU (S504).

[0041] (Example of processing performed by a communication device upon reception) Next, the processing flow performed by the communication device 100 when it performs reception processing will be explained. Since both AP101 and STA110 can receive data, the communication device 100 in this example may be either AP101 or STA110. In this example as well, the communication device 100 is capable of performing communication compliant with a first standard and communication compliant with a second standard included in the IEEE 802.11 standard series. That is, the communication device 100 can perform reception processing of PPDUs compliant with the first standard and reception processing of PPDUs compliant with the second standard. Figure 6 shows an example of the processing flow performed by the communication device 100 when it performs reception processing of a PPDU. This processing flow may be started, for example, based on the communication device 100 detecting that a PPDU has been input via its antenna 207.

[0042] The communication device 100 receives the PPDU (S601). The communication device 100 analyzes information such as the preamble based on the format of the received PPDU. For example, the communication device 100 can identify each area containing information to be analyzed based on the setting value of a field for identifying the format of the PPDU included in the preamble. For example, if the preamble contains information that allows for the identification of the standard to which the received PPDU conforms, the communication device 100 can identify the standard to which the PPDU conforms based on this information. Furthermore, by analyzing the first area described above, the communication device 100 can obtain information indicating the MCS table to be used to identify the MCS from the MCS index included in this PPDU. In addition, by analyzing the second area described above, the communication device 100 can obtain the MCS index.

[0043] The communication device 100 determines which MCS table should be used to identify the MCS from the MCS index contained in the received PPDU (S602). For example, the communication device 100 may determine which MCS table to use based on the setting value of the first area of ​​the received PPDU. If the MCS tables specified for each standard are different, the communication device 100 may determine which MCS table to use by using information to identify the format of the PPDU or information indicating the standard to which the PPDU conforms. If the communication device 100 determines that the first MCS table should be used (YES in S602), it interprets the MCS index obtained from the second area of ​​the PPDU based on the MCS table of the first standard (S603). That is, the communication device 100 uses the first MCS table to identify the MCS corresponding to the acquired MCS index. The communication device 100 demodulates the data signal and acquires the data, assuming that the identified MCS was used in generating the data signal contained in the received PPDU (S605).

[0044] On the other hand, when the communication device 100 determines that the second MCS table should be used (NO in S602), it interprets the MCS index obtained from the second region of the PPDU based on the MCS table of the second standard (S604). That is, the communication device 100 uses the first MCS table to identify the MCS corresponding to the obtained MCS index. In generating the data signal included in the received PPDU, the communication device 100 demodulates this data signal assuming that the identified MCS was used and acquires the data (S605).

[0045] (Format of PPDU compliant with IEEE 802.11be standard) An example of the format of the PPDU used between communication devices will be described. FIG. 7A shows a configuration example of an EHT MU PPDU compliant with the IEEE 802.11be standard. EHT MU PPDU is an abbreviation for Extremely High Throughput Multi-user PPDU. This frame format can be an example of the frame format of the PPDU compliant with the second standard in this example. The EHT MU PPDU can be used in downlink communication from the AP 101 to the STA 110. Also, the EHT MU PPDU can be used when the STA 110 performs uplink communication by single-user communication (SU) or the like. FIG. 7B similarly shows a configuration example of an EHT TB PPDU compliant with the IEEE 802.11be standard. EHT TB PPDU is an abbreviation for Extremely High Throughput Trigger based PPDU. This frame format can also be an example of the frame format of the PPDU compliant with the second standard in this example. The EHT TB PPDU can be used in uplink communication from the STA 110 to the AP 101 based on the Trigger frame transmitted by the AP 101. Hereinafter, first, the EHT MU PPDU will be described, and then the EHT TB PPDU will be described.

[0046] (EHT MU PPDU Format) An EHT MU PPDU may consist of L-STF701, L-LTF702, L-SIG703, RL-SIG704, U-SIG705, EHT-SIG706, EHT-STF707, and EHT-LTF708. An EHT MU PPDU may contain one or more EHT-LTF708. L-STF701 to EHT-LTF708 may be called preambles. STF is an abbreviation for Short Training Field. LTF is an abbreviation for Long Training Field. SIG is an abbreviation for Signal Field. Furthermore, the EHT-MU PPDU may include Data 709 and Package Extension 710.

[0047] L-STF701 to L-SIG703 are fields designed to ensure backward compatibility with legacy standards (IEEE 802.11a / b / g / n / ac / ax, etc.). That is, communication devices compatible with legacy standards can recognize the information contained in L-STF701 to L-SIG703. L-STF701 is used for wireless frame detection, automatic gain control, timing detection, etc. Automatic gain control may be called Automatic Gain Control (AGC). L-LTF702 is used for high-precision frequency synchronization, timing synchronization, acquisition of propagation channel information, etc. Propagation channel information may be called Channel State Information (CSI). L-SIG703 is used to notify control information such as the length of the PPDU (packet length). RL-SIG704 can be composed of multiple L-SIG703s. For example, the presence of RL-SIG704 in a PPDU may indicate that this PPDU is a standard released after the IEEE 802.11ax standard. EHT-STF707 can be used for automatic gain control in MIMO communication. MIMO is an abbreviation for Multiple Input, Multiple Output. EHT-LTF708 can be used to estimate the MIMO channel in the receiving communication device. Data709 is a data signal. Data709 is a region containing the data to be communicated and may include, for example, one or more MPDUs. MPDU is an abbreviation for Medium Access Control (MAC) Protocol Data Unit. The data signal in Data 709 may be generated using an MCS selected by the communication device 100. Packet Extension 710 may be used to provide additional reception processing time to the receiving communication device 100.

[0048] U-SIG705 contains information for the receiving communication device 100 to interpret the EHT MU PPDU. Examples of the information contained in U-SIG705 are shown in FIGS. 16A and 16B. U-SIG705 can be composed of two parts, U-SIG-1 and U-SIG-2. U-SIG705 can have a common part independent of the standard and a standard-specific part dependent on the standard. For example, the five subfields of PHY Version Identifier, Bandwidth, UL / DL, BSS Color, and TXOP contained in U-SIG-1 can be a common part independent of the standard. The PHY Version Identifier subfield can indicate information specifying the configuration of the PHY layer as the PHY version. As an example, a value of 0 can be set for a PPDU compliant with the IEEE802.11be standard. Also, as described later, for a PPDU compliant with the IEEE802.11bn standard, a value greater than 0 (for example, a value of 1) can be set. Thus, since the PHY Version Identifier subfield can be used to specify the standard to which the PPDU conforms, it can be used as the first region in the above-mentioned PPDU. The SIG MCS subfield in U-SIG-2 indicates the MCS index corresponding to the MCS used for generating EHT-SIG706 following U-SIG705.

[0049] EHT-SIG706 contains additional information for interpreting the EHT MU PPDU. While the U-SIG705 mentioned above contains standard-independent information, EHT-SIG706 can be flexibly configured according to the provisions of a standard (e.g., the IEEE 802.11be standard). Figures 8A to 8C show examples of the configuration of EHT-SIG706 in an EHT MU PPDU used when the communication device 100 performs OFDMA transmission. OFDMA is an abbreviation for Orthogonal Frequency-Division Multiple Access. Figure 8A shows an example of the configuration of EHT-SIG706 when EHT MU PPDUs with bandwidths of 20 MHz, 40 MHz, and 80 MHz are used. Figure 8B shows an example configuration of the EHT-SIG706 when an EHT MU PPDU with a bandwidth of 160 MHz is used. Figure 8C shows an example configuration of the EHT-SIG706 when an EHT MU PPDU with a bandwidth of 320 MHz is used. Figures 9A to 9C show an example configuration of the EHT-SIG706 in an EHT MU PPDU used when the communication device 100 performs transmission other than OFDMA transmission. Figure 9A shows an example configuration of the EHT-SIG706 in an EHT MU PPDU used when the communication device 100 performs single-user (SU) transmission. Figure 9B shows an example configuration of the EHT-SIG706 in an EHT MU PPDU used when the communication device 100 performs multi-user transmission without using OFDMA. Figure 9C shows an example configuration of the EHT-SIG706 in the EHT MU PPDU used when the communication device 100 transmits a Sounding NDP. Below, we will first explain Figure 8A, and then explain Figures 8B, 8C, and 9A-C in that order.

[0050] (Example configuration of EHT-SIG for EHT MU PPDU used for OFDMA transmission) The EHT-SIG 706 shown in Figure 8A is configured to include a Common field 801 and a User Specific field 802. The Common field 801 contains information that should be commonly used by one or more communication devices 100 that should receive this PPDU. The Common field 801 may include subfields of U-SIG overflow, one or two RU allocation-A, CRC, and Tail as region 803. Examples of information included in the Common field 801 are shown in Figures 17A and 17B. Note that region 803 in the example configuration of EHT-SIG 706 shown in Figure 8A corresponds to the portion B0 to B26+9N in Figures 17A and 17B. For example, the portion B0-B16 in Figures 17A and 17B corresponds to the U-SIG overflow subfield in region 803. Also, region 803 in the example configuration of EHT-SIG706 shown in Figure 8A does not include the portion B27+9N to B36+9N+9M in Figures 17A and 17B. The portion B27+9N to B36+9N+9M in Figures 17A and 17B may be included in the example configuration of EHT-SIG706 shown in Figure 8B, which will be described later.

[0051] The User Specific field 802 contains information that is individually notified to each of the one or more communication devices 100 that should receive this PPDU. In the following, "User" may refer to the communication device 100 used by that user. For example, the area allocated to each user may refer to the area allocated to the communication device 100 used by each user. As an example, area 804 may be allocated to STA 111 in Figure 1, and area 805 may be allocated to STA 112. Areas 804 and 805 may each consist of two User fields, a CRC subfield, and a Tail subfield. An example of the information contained in areas 804 and 805 is shown in Figure 18. Also, examples of the information contained in the User field of Figure 18 are shown in Figures 19 and 20. Figure 19 shows an example of the information contained in areas 804 and 805 when MU-MIMO is not used in the transmission of the PPDU. Figure 20 also shows an example of the information contained in areas 804 and 805, etc., when MU-MIMO is used in PPDU transmission. In both Figure 19 and Figure 20, a 4-bit MCS subfield is provided in the User field. The communication device 100 can use this MCS subfield to notify each of the other communication devices of the MCS index of the MCS used to generate the data signal. For example, AP 101 can transmit downlink data destined for STA 111 and STA 112, respectively, using OFDMA with EHT MU PPDU. In this case, AP 101 can notify STA 111 of the MCS index corresponding to the MCS used to generate the data signal destined for STA 111 by setting it in the MCS subfield included in area 804 allocated to STA 111. Similarly, AP101 can notify STA112 by setting the MCS index corresponding to the MCS used to generate the data signal destined for STA112 in the MCS subfield included in the area 805 allocated to STA112. The STA-ID subfields included in area 804 and area 805, respectively, are set with STA-IDs indicating STA111 and STA112.STA111 and STA112 can identify areas 804 and 805 assigned to their own devices by detecting the STA-ID subfield in which their own device's STA-ID is set. Furthermore, STA111 and STA112 can identify the MCS used to generate the data signal destined for their own devices by the MCS index set in the MCS subfield in each of areas 804 and 805. Thus, the 4-bit MCS subfield in the User field can be used as a second area of ​​the PPDU for notifying the aforementioned MCS index.

[0052] Next, we will describe an example configuration of the EHT-SIG706 shown in Figures 8B and 8C. Figure 8B is an example configuration of the EHT-SIG706 included in an EHT MU PPDU with a bandwidth of 160 MHz. This example configuration differs from the example configuration of the EHT-SIG706 shown in Figure 8A in that it includes two subfields, RU Allocation-B, CRC, and Tail, as region 814 of the Common field 811. Region 814 corresponds to the B27+9N to B36+9N+9M portion of Figures 17A and 17B described above. In other words, the EHT-SIG706 shown in Figure 8B includes more information to notify the allocation of Resource Units (RUs) in order to support OFDMA transmission using an EHT MU PPDU with a bandwidth of 160 MHz. Furthermore, Figure 8C shows an example configuration of the EHT-SIG706 included in a 320 MHz bandwidth EHT MU PPDU. This example configuration differs from the EHT-SIG706 configurations shown in Figures 8A and 8B in that it includes six RU Allocation-B subfields in region 824 of the Common field 821. In other words, the EHT-SIG706 shown in Figure 8C includes more information to indicate the RU arrangement in order to support OFDMA transmission using a 320 MHz bandwidth EHT MU PPDU.

[0053] In both of the configuration examples of the EHT-SIG706 shown in Figure 8B and Figure 8C, the configuration of the User Specific field is the same, so its explanation is omitted. That is, in both of the configuration examples of the EHT-SIG706 shown in Figure 8B and Figure 8C, the 4-bit MCS subfield in the User field can be used as a second area of ​​the PPDU for notifying the MCS index mentioned above.

[0054] (Example of EHT-SIG configuration for EHT MU PPDU used for SU transmission) An example of the configuration of the EHT-SIG 706 shown in Figure 9A will be described. Figure 9A shows an example of the configuration of the EHT-SIG 706 in an EHT MU PPDU used when the communication device 100 performs single-user (SU) transmission. The EHT-SIG 706 shown in Figure 9A is composed of a Common field 901 and a User Specific field 902. The Common field 901 and the User Specific field 902 may be composed of a single OFDM symbol. The Common field 901 may include the subfields U-SIG overflow and Number of Non-OFDMA Users. An example of the information contained in the Common field 901 is shown in Figure 21. The portion B0-B16 in Figure 21 is the same as the portion B0-B16 in Figures 17A and 17B, that is, it corresponds to the U-SIG overflow subfield in region 903. The information contained in region 903 differs from the information contained in region 803 in Figure 8A, etc., in that it contains Number of non-OFDMA Users (B17-B19).

[0055] The User Specific field 902 may include a region 904 and a Padding 905. Region 904 may consist of one User field, a CRC subfield, and a Tail subfield. An example of the information contained in the User Specific field 902 is shown in Figure 22. Note that Figure 22 includes the information contained in the Common field 901 described above, as B0-B19. Therefore, B20-B51 in Figure 22 shows the information contained in the User Specific field 902, and its contents are the same as those of the User Specific field 802 shown in Figure 18. Also, the User field (B20-B41) in Figure 22 is configured in the same way as the User field shown in Figure 19. Therefore, even when performing single-user (SU) transmission, the 4-bit MCS subfield in the User field included in the EHT MU PPDU can be used as a second area of ​​the PPDU for notifying the aforementioned MCS index.

[0056] (Example of EHT-SIG configuration for EHT MU PPDU used when performing multi-user transmission without using OFDMA) An example of the configuration of EHT-SIG 706 shown in Figure 9B will be described. Figure 9B shows an example of the configuration of EHT-SIG 706 in an EHT MU PPDU used when the communication device 100 performs multi-user transmission without using OFDMA. The EHT-SIG 706 shown in Figure 9B is configured to include a Common field 911 and a User Specific field 912. The Common field 911 is configured in the same way as the Common field 901 in Figure 9A. That is, the Common field 911 differs from the Common field 901 in Figure 9A in that the value of the Number Of non-OFDMA Users (B17-B19) subfield in Figure 21 is set to 1 or more. For example, when AP101 sends multiple data points to STA111 and STA112 respectively using MU-MIMO, the value of the Number Of non-OFDMA Users subfield is set to 1.

[0057] The User Specific field 912 comprises at least region 914 and region 915. Region 914 is configured similarly to region 904 in Figure 9A and includes one User field, CRC, and Tail. Region 905 includes two User fields, CRC, and Tail. The User Specific field 912 may further include regions 916 and 917. That is, the User Specific field 912 may include User fields corresponding to each of the communication devices 100 that are destinations for multi-user transmissions. The information contained in each User field in the User Specific field 912 is the same as in Figure 20. Therefore, even when the communication device 100 performs multi-user transmission without using OFDMA, the 4-bit MCS subfield in the User field of the PPDU can be used as a second area of ​​the PPDU for notifying the aforementioned MCS index.

[0058] (Example of EHT-SIG configuration for EHT MU PPDU used for Sounding NDP transmission) An example of the configuration of the EHT-SIG 706 shown in Figure 9C will be described. Figure 9C shows an example of the configuration of the EHT-SIG 706 in an EHT MU PPDU used by the communication device 100 for Sounding NDP transmission. Sounding NDP is a null data packet used when performing channel estimation between communication devices. The EHT-SIG 706 shown in Figure 9C is composed of a Common field 921. That is, the example of the EHT-SIG 706 configuration shown in Figure 9C differs from other EHT-SIG 706s in that it does not have a User Specific field. The Common field 921 is composed of a region 922. An example of the information contained in region 922 is shown in Figure 23. Since Sounding NDP is a null data frame, it does not contain data signals. Therefore, the EHT MU PPDU used for transmitting Sounding NDP does not include the area corresponding to the second area of ​​the PPDU for notifying the MCS index mentioned above.

[0059] Thus, when the communication device 100 uses an EHT MU PPDU, it can use the PHY Version Identifier subfield of U-SIG705 to notify the other communication device that the PPDU conforms to the second standard. This allows the other communication device to determine that it should identify the MCS from the MCS index using the second MCS table. The communication device 100 can also use the 4-bit MCS subfield in EHT-SIG706 to notify the other communication device of the MCS index corresponding to the MCS used to generate the data signals contained in the PPDU. Note that the configuration examples and information included in the tables used in the above explanation are illustrative. For example, other fields and subfields may be included in the above configuration examples and tables, and some fields and subfields may be omitted. Also, each field and subfield may be used to indicate other information. Furthermore, the names of each field and subfield may be defined differently.

[0060] (EHT TB PPDU Format) The EHT TB PPDU is described below. The EHT TB PPDU can be used in uplink communication from STA 110 to AP 101, based on a Trigger frame transmitted by AP 101. Figure 7B shows an example of the frame format of the EHT TB PPDU. In Figure 7B, the same reference numbers are used for components similar to those in Figure 7A. As can be seen by comparing Figure 7A and Figure 7B, the EHT TB PPDU does not have an EHT-SIG 706. Also, the U-SIG 711 of the EHT TB PPDU may contain different information than the U-SIG 705 in the EHT MU PPDU. An example of the information contained in the EHT TB PPDU is shown in Figures 24A and 24B. As described above, the five fields (B0-B19) in the U-SIG-1 of the EHT TB PPDU, from the PHY Version Identifier subfield to the TXOP subfield, are configured in the same way as the U-SIG-1 of the EHT MU PPDU. Therefore, in the EHT TB PPDU as well, the PHY Version Identifier subfield can be used to indicate that this PPDU conforms to the second standard. On the other hand, as described above, since the EHT TB PPDU does not have EHT-SIG706, it is not possible to notify the other party's communication device of the MCS index corresponding to the MCS used to generate the data signal. Therefore, in this example, when the communication device 100 transmits using the EHT TB PPDU, it generates a data signal using the MCS corresponding to the MCS index notified by the Trigger frame received prior to the transmission of the PPDU. For example, when STA111 and STA112 transmit uplink OFDMA to AP101 using the EHT TB PPDU, AP101 first sends a Trigger frame to STA111 and STA112. In the Trigger frame, AP101 notifies STA111 and STA112 of the MCS index corresponding to the MCS that each of them should use.STA111 and STA112 generate the EHT TB PPDU data signal transmitted by their respective devices using the MCS corresponding to the MCS index notified to them. This configuration allows the technology to be applied to EHT TB PPDUs as well. An example of the Trigger frame configuration is described below.

[0061] (Trigger Frame Format) Figure 10 shows an example of the Trigger frame format. A Trigger frame is one of the MAC frames. A Trigger frame may consist of the following fields: Frame Control 1001, Duration 1002, RA 1003, TA 1004, Common Info 1005, and User Info List 1006. A Trigger frame may also include the following fields: Padding 1007 and FCS 1008. In a Trigger frame, Common Info 1005 and User Info List 1006 may be called the MAC frame body. Frame Control 1001 contains control information such as the frame type. For example, in the case of a Trigger frame, the Type subfield in the Frame Control field 1001 may be set to the value "01", and the Subtype subfield may be set to the value "0010". The Duration field 1002 may be used to indicate the period during which data or other communications are performed. RA 1003 may be set to information indicating the receiving communication device. TA 1004 may be set to information indicating the transmitting communication device. The information indicating the receiving and transmitting communication devices may be the MAC address, AID, BSSID, etc. of the communication device. The Padding field 1007 may be used to adjust the length of the MAC frame. The FCS field 1008 may be used by the receiving communication device 100 to determine whether or not the MAC frame has been successfully received.

[0062] The Common Info field 1005 may include the HE / EHT / UHR P160 subfield 1009 and the Special User Info Field Flag subfield 1010. The HE / EHT / UHR P160 subfield 1009 may also be the HE / EHT P160 subfield. The HE / EHT / UHR P160 subfield 1009 may be used to indicate the type of PPDU to be transmitted based on the Trigger frame containing this subfield. For example, AP 101 may use the HE / EHT / UHR P160 subfield 1009 to specify the standard to which the subsequent PPDU should conform. As an example, if the HE / EHT / UHR P160 subfield 1009 is set to 0, it indicates that an EHT TB PPDU should be transmitted. Furthermore, if the HE / EHT / UHR P160 subfield 1009 is set to 1, it indicates that an HE TB PPDU should be transmitted. Additionally, if the HE / EHT / UHR P160 subfield 1009 is set to 2, it indicates that a UHR TB PPDU should be transmitted. The values ​​of the HE / EHT / UHR P160 subfield 1009 associated with HE TB PPDU, EHT TB PPDU, and UHR TB PPDU may differ from these. STA 110 may transmit using a PPDU conforming to the specified standard. The HE / EHT / UHR P160 subfield 1009 may be used to identify the MCS table that the communication device 100 should use. For example, if the value set in the HE / EHT / UHR P160 subfield 1009 indicates that an EHT TB PPDU should be sent, it may indicate that a second MCS table should be used. The Special User Info Field Flag subfield 1010 indicates whether the subsequent User Info List field 1006 contains a Special User Info field. For example, setting the value to 0 indicates that the Special User Info field may be included.

[0063] The User Info List field 1006 may contain one or more User Info fields 1011. Each User Info field 1011 corresponds to each STA 110 that should transmit a PPDU based on a Trigger frame. Each User Info field 1011 also indicates the communication parameters to be used in the PPDU transmitted by each STA. Figure 11A shows an example configuration of User Info field 1011. The User Info field 1011 may contain the subfields AID 12 1101, RU allocation 1102, UL FEC Coding Type 1103, UL HE / EHT-MCS 1104, and UL DCM 1105. Furthermore, the User Info field 1011 may include the subfields SS Allocation / RA-RU information 1106 and UL Target Receive Power 1107. Additionally, the User Info field 1011 may include the subfields Reserved 1108 and Trigger Dependen User Info 1109.

[0064] The AID12 subfield 1101 indicates the identifier (AID) of the communication device 110 associated with the User Info field 1011. AID is an abbreviation for Association ID. If the value 2007 is set in the AID12 subfield 1101, it indicates that the User Info field 1011 containing this AID12 subfield is a Special User Info field. The Special User Info field will be described later. RU Allocation 1102 indicates the RU that each of the STA 110 should use in the EHT TB PPDU. UL FEC Coding Type 1103 indicates the coding that each of the STA 110 should use in the EHT TB PPDU. For example, if the value of UL FEC Coding Type 1103 is 0, it indicates that BCC should be used. Also, if the value of UL FEC Coding Type 1103 is 1, it indicates that LDPC should be used. BCC is an abbreviation for Binary Convolutional Coding. LDPC is an abbreviation for Low Density Party Check.

[0065] The UL HE / EHT-MCS1104 indicates the MCS index that each STA110 should use to generate the data signal. Based on the value set in the HE / EHT / UHR P160 subfield 1009, the STA110 can identify the MCS table to be used to identify the MCS from the MCS index shown in the UL HE / EHT-MCS1104. For example, if the STA110 determines, based on the value set in the HE / EHT / UHR P160 subfield 1009, that it should transmit a PPDU conforming to a second standard, it can use the second MCS table to identify the MCS from the MCS index. The STA110 generates the data signal using the identified MCS. By the STA110 generating the data signal using the specified MCS, the AP101 can demodulate the received data signal based on the MCS specified by its device and acquire the data. UL DCM 1105 indicates whether STA 110 should use DCM in EHT TB PPDU. DCM is an abbreviation for Dual Carrier Modulation. SS Allocation / RA-RU information 1106 indicates the number of spatial streams that each STA 110 should use in EHT TB PPDU. UL Target Receive Power 1107 indicates the received power that AP 101 expects. Reserved 1108 is a reserved area. Dependent User Info 1109 is an optional subfield that is set based on the type of Trigger frame.

[0066] The Special User Info field is described below. The Special User Info field is identified by the value 2007 being set in the AID12 subfield 1101 of the User Info field. The Special User Info field contains information commonly used by STA 100, which receives this Trigger frame, and indicates the information that STA 110 should use for the U-SIG of the EHT TB PPDU. An example of the configuration of the Special User Info field is shown in Figure 11B. The Special User Info field may include the subfields AID12 1111, PHY Version Identifier 1112, and UL Bandwidth Extension 1113. The Special User Info field may include EHT / UHR Spatial Reuse1 1114, EHT / UHR Spatial Reuse2 1115, and U-SIG Disregard And Validate1116. The AID12 1111 is set to a value of 2007 to indicate that this User Info field is a Special User Info field. Each of the subfields PHY Version Identifier1112 to U-SIG Disregard And Validate1116 can be used in the U-SIG of the EHT TB PPDU shown in Figures 24A and 24B. For example, if the value of PHY Version Identifier 1112 is set to 0, it indicates that it is an EHT TB PPDU compliant with the IEEE 802.11be standard. Therefore, AP 101 may use PHY Version Identifier 1112 in the Special User Info field to specify the type of PPDU that STA 110 should use. In this case, PHY Version Identifier 1112 in the Special User Info field may be used to specify the MCS table to be used.

[0067] Thus, when STA110 transmits using an EHT TB PPDU, an EHT TB PPDU may be generated by AP101 based on the information specified using the Trigger frame. For example, AP101 may notify STA110 that a PPDU conforming to the second standard should be used using the HE / EHT / UHR P160 subfield 1009 of the Trigger frame. Alternatively, AP101 may notify STA110 that a PPDU conforming to the second standard should be used using the PHY Version Identifier 1112 of the Special User Info field of the Trigger frame. In these cases, AP101 may use these areas to notify STA110 of the MCS table that it should use. Furthermore, AP101 may use the 4-bit UL HE / EHT-MCS subfield in the User Info field to notify STA110 of the MCS index corresponding to the MCS that STA110 should use to generate the data signal. Note that other areas of the Trigger frame may be used to notify STA110 that AP101 should use the second MCS table and to provide the MCS index corresponding to the MCS that should be used to generate the data signal.

[0068] (UHR PPDU Format) Another example of a PPDU format used between communication devices is described. Figures 12A and 12B show an example of a UHR PPDU configuration. This frame format may be an example of a PPDU frame format conforming to the first standard (IEEE 802.11bn standard) in this example. The frame format shown in Figure 12A may be called a UHR MU PPDU. UHR MU PPDU may be an abbreviation for Ultra High Reliability Multi-user PPDU. The UHR MU PPDU may be used in downlink communication from AP101 to STA110. The UHR MU PPDU may also be used when STA110 performs uplink communication using single-user communication (SU), etc. The frame format shown in Figure 12B may be called UHR TB PPDU. UHR TB PPDU may be an abbreviation for Ultra High Reliability Trigger-based PPDU. UHR TB PPDU may be used in uplink communication from STA 110 to AP 101, based on a Trigger frame transmitted by AP 101. In Figures 12A and 12B, the same reference numbers are used for configurations similar to those in Figures 7A and 7B, and their explanations are omitted. Below, the PPDU format of the first standard will be explained, focusing on the differences from the PPDU format of the second standard.

[0069] The UHR MU PPDU may consist of L-STF701, L-LTF702, L-SIG703, RL-SIG704, U-SIG705, UHR-SIG1201, UHR-STF1202, and UHR-LTF1203. The UHR MU PPDU may include one or more UHR-LTF1203. In Figure 12A, L-STF701 to UHR-LTF1203 may be called a preamble. The UHR MU PPDU may also include Data709 and Package Extension710. UHR-STF1202 and UHR-LTF1203 may be configured similarly to EHT-STF707 and EHT-LTF708, respectively, or they may be configured differently. The UHR MU PPDU is not limited to the configuration shown in Figure 12A; for example, some of the fields included in Figure 12A may be omitted, while other fields may be included.

[0070] The U-SIG705 in the UHR MU PPDU may have at least some common components with the U-SIG705 in the EHT MU PPDU shown in Figures 16A and 16B. For example, the five subfields from the PHY Version Identifier subfield to the TXOP subfield (B0-B19) may be configured in the same way as in Figures 16 and 16B. Here, as mentioned above, the PHY Version Identifier subfield may be used to identify the standard to which the PPDU conforms. For example, in the case of the EHT MU PPDU, a value of 0 may be set, and in the case of the UHR MU PPDU, a value of 1 may be set. The receiving communication device 100 can analyze the information contained in the received PPDU based on the EHT MU PPDU format if the value set in the PHY Version Identifier subfield is 0. Furthermore, if the value set in the PHY Version Identifier subfield is 1, the receiving communication device 100 can analyze the information contained in the received PPDU based on the UHR MU PPDU format. In this way, by including an area indicating the standard to which the PPDU conforms in a subfield commonly provided between different standards, the receiving communication device 100 can identify the format and standard to be used for analyzing the information contained in the received PPDU.

[0071] The PHY Version Identifier subfield can be used as a first area of ​​the PPDU containing information to identify the MCS table that the receiving communication device 100 should use. If the MCS tables specified for each standard are different, the communication device 100 can identify the MCS table that it should use by identifying the standard to which the PPDU conforms. By utilizing a subfield that exists in the legacy standard as the first area of ​​the PPDU containing information to identify the MCS table that the receiving communication device 100 should use, it becomes unnecessary to create a new subfield. This reduces the amount of information that needs to be included in the PPDU preamble.

[0072] The Disregard subfield and Validate subfield included in U-SIG-1 may be used as the first area of ​​the PPDU. By using the unused area in U-SIG-1 of the EHT MU PPDU to identify the MCS table that the receiving communication device 100 should use, it is possible to notify the MCS table to be used flexibly regardless of the correspondence between the standard and the MCS table. For example, in cases where a common MCS table is used in multiple standards, or where multiple different MCS tables are used in one standard, it may be better to notify the difference (version) of the MCS table rather than the difference in the standard. In this case, the first area of ​​the PPDU may be set with identification information assigned to each MCS table. The Validate subfield and other subfields included in U-SIG-2 may also be used as the first area. If U-SIG-2 is configured differently for each standard, the first area of ​​the PPDU can be flexibly arranged to match the arrangement of other information by using U-SIG-2 to identify the MCS table that the receiving communication device 100 should use.

[0073] The SIG MCS subfields (B9-B10) of U-SIG-2 can be set based on a first MCS table. For example, the communication device 100 can use the first MCS table to set the MCS index corresponding to the MCS used to generate UHR-SIG1201 in the SIG MCS subfield. Note that the fields following U-SIG705 (EHT-SIG706 and UHR-SIG1201) may have different configurations depending on the standard. Therefore, the MCS used to generate the fields following U-SIG705 may be different depending on the standard, or a common MCS may be used regardless of the standard. For example, an MCS not used to generate EHT-SIG may be used as the MCS used to generate UHR-SIG. In this case, the MCS index associated with the value indicated by the SIG MCS subfield may differ from standard to standard, and the MCS associated with that MCS index may also differ from standard to standard. For example, the MCS with the smallest MCS index in the MCS table of each standard may be used in order to generate the fields following U-SIG705. On the other hand, the MCS used to generate EHT-SIG may be used as the MCS used to generate UHR-SIG. In this case, the MCS index associated with the value indicated by the SIG MCS subfield may be common regardless of the standard, and the MCS associated with that MCS index may also be common regardless of the standard. For example, a commonly defined MCS from the MCS tables defined in each standard may be used to generate the fields following U-SIG705.

[0074] The UHR-SIG1201, like the EHT-SIG706, can be configured using different formats depending on the transmission method used for transmitting the UHR MU PPDU. For example, the UHR-SIG1201 in a UHR MU PPDU used when the communication device 100 performs OFDMA transmission may be configured similarly to the EHT-SIG706 shown in Figure 8A, or it may be configured differently. As an example, when the UHR-SIG1201 is configured similarly to Figure 8A, examples of the information contained in the User field of the UHR-SIG1201 are shown in Figures 25 and 26. Figure 25 shows an example of the information contained in the User field when MU-MIMO is not used for PPDU transmission. Figure 26 shows an example of the information contained in the User field when MU-MIMO is used for PPDU transmission. The User field of the UHR-SIG1201 shown in Figure 25 differs from the User field of the EHT-SIG706 shown in Figure 19 in that the MCS subfield (B11-B15) is configured as a 5-bit area. Similarly, the User field of the UHR-SIG1201 shown in Figure 26 differs from the User field of the EHT-SIG706 shown in Figure 20 in that the MCS subfield (B11-B15) is configured as a 5-bit area. As will be described later, by configuring the MCS subfield (B11-B15) as a 5-bit area, it becomes possible to assign an MCS index that uniquely identifies each MCS as defined in the IEEE 802.11bn standard.

[0075] In Figure 25, the Reserved subfield (B15) in Figure 19 is used to configure the MCS subfield (B11-B15) of the UHR-SIG1201 as a 5-bit area. In this way, by using an area not used in the EHT-SIG706, a 5-bit area can be secured as the MCS subfield without affecting the arrangement of other information. Alternatively, to secure a 5-bit area as the MCS subfield, a portion of other subfields used in the User field of the EHT-SIG706 may be used. Alternatively, the size of the User field may be increased to secure a 5-bit area as the MCS subfield. In addition, the MCS subfield of the UHR-SIG1201 may be set to 4 bits, with a 1-bit area provided to extend the MCS subfield. For example, the above-mentioned Reserved subfield (B15) may be set as the extension area. In this case, the MCS can be associated with a combination of a 4-bit MCS subfield and a 1-bit extension subfield.

[0076] Figure 26 shows an example of using one bit from the Spatial Configuration subfield in Figure 20 to configure the MCS subfield (B11-B15) of the UHR-SIG1201 as a 5-bit area. To reserve a 5-bit area as the MCS subfield, some of the other subfields used in the User field of the EHT-SIG706 may be used. Alternatively, the size of the User field may be increased to reserve a 5-bit area as the MCS subfield.

[0077] In the above, an example configuration of the UHR-SIG1201 used when the communication device 100 uses UHR MU PPDUs with bandwidths of 20 MHz, 40 MHz, and 80 MHz for OFDMA transmission was described with reference to Figure 8A. Next, an example configuration of the UHR-SIG1201 used when the communication device 100 uses UHR MU PPDUs with bandwidths of 160 MHz and 320 MHz for OFDMA transmission will be described. When the communication device 100 performs OFDMA transmission using a UHR MU PPDU with a bandwidth of 160 MHz, the UHR-SIG1201 may be configured in the same way as the example configuration of the EHT-SIG706 shown in Figure 8B, or it may be configured differently. For example, if the UHR-SIG1201 is configured similarly to the configuration example of the EHT-SIG706 shown in Figure 8B, the User field included in the UHR-SIG1201 may be configured as shown in Figure 25 or Figure 26. Also, if the communication device 100 performs OFDMA transmission using a UHR MU PPDU with a bandwidth of 320 MHz, the UHR-SIG1201 may be configured similarly to the configuration example of the EHT-SIG706 shown in Figure 8C, or it may be configured differently. For example, if the UHR-SIG1201 is configured similarly to the configuration example of the EHT-SIG706 shown in Figure 8C, the User field included in the UHR-SIG1201 may be configured as shown in Figure 25 or Figure 26. Therefore, when the communication device 100 uses a UHR MU PPDU for OFDMA transmission, a 5-bit MCS subfield can be secured by configuring the User field as shown in Figure 25 or Figure 26, regardless of the bandwidth of the PPDU.

[0078] The UHR-SIG1201 in the PPDU (UHR MU PPDU) conforming to the first standard used when the communication device 100 performs SU transmission may be configured in the same way as in Figure 9A, or it may be configured differently. For example, if the UHR-SIG1201 is configured in the same way as the configuration example of the EHT-SIG706 shown in Figure 9A, the User field included in the UHR-SIG1201 may be configured as shown in Figure 25. Also, the UHR-SIG1201 in the UHR MU PPDU used when the communication device 100 performs multi-user transmission without using OFDMA may be configured in the same way as in Figure 9B, or it may be configured differently. For example, if the UHR-SIG1201 is configured in the same way as the configuration example of the EHT-SIG706 shown in Figure 9B, the User field included in the UHR-SIG1201 may be configured as shown in Figure 26. Therefore, even when the communication device 100 performs SU transmission or multi-user transmission without using OFDMA using a UHR MU PPDU, a 5-bit MCS subfield can be secured by configuring the User field as shown in Figure 25 or Figure 26.

[0079] Thus, when communication device 100 uses a UHR MU PPDU, it can use the PHY Version Identifier subfield of U-SIG705 to notify the other party's communication device that it is a PPDU conforming to the first standard. This allows the other party's communication device to determine that it should identify the MCS from the MCS index using the first MCS table. Alternatively, communication device 100 may use other areas of the preamble to notify the other party's communication device that it should use the first MCS table. For example, communication device 100 may use an area included in U-SIG705, which is commonly used with PPDUs conforming to the second standard, to notify the other party's communication device that it should use the first MCS table and that it is a PPDU conforming to the first standard. Furthermore, the communication device 100 may use the 5-bit MCS subfield in the UHR-SIG1201 to notify the other party's communication device of the MCS index corresponding to the MCS used to generate the data signal included in the PPDU. Alternatively, the communication device 100 may use other areas of the preamble to notify the other party's communication device of the MCS index corresponding to the MCS used to generate the data signal. For example, the communication device 100 may use any area included in the UHR-SIG1201, which can be flexibly configured in the standard to which the PPDU conforms, to notify the other party's communication device of the MCS index corresponding to the MCS used to generate the data signal.

[0080] (Format of UHR TB PPDU) The UHR TB PPDU will be described. As shown in FIG. 12B, the UHR TB PPDU does not have the UHR-SIG1201, similar to the EHR TB PPDU. Therefore, similar to the EHR TB PPDU, the communication device 100 generates a data signal using the MCS corresponding to the MCS index notified by the Trigger frame received prior to the transmission of the UHR TB PPDU. By configuring in this way, the present technology can also be applied to the UHR TB PPDU. Note that the U-SIG711 of the UHR TB PPDU can have the same configuration as the U-SIG705 of the UHR MU PPDU shown in FIGS. 24A and 24B in terms of the PHY Version Identifier subfield to the TXOP subfield (B0 - B19). Also, information indicating the PHY version corresponding to the IEEE802.11bn standard can be set as the value of the PHY Version Identifier subfield. For example, 1 can be set as the value of the PHY Version Identifier subfield. Thereby, the communication device 100 can notify the other communication device that this PPDU complies with the first standard by using the PHY Version Identifier subfield even in the UHR TB PPDU.

[0081] (Trigger Frame Format) The Trigger frame for transmitting a UHR TB PPDU is described below. The format of the Trigger frame for transmitting a UHR TB PPDU may be configured similarly to the frame format shown in Figure 10, or it may be configured differently. When the Trigger frame is configured similarly to the frame format shown in Figure 10, the value of the HE / EHT / UHR P160 subfield 1009 may be set to a value indicating that a UHR TB PPDU should be transmitted. For example, the value of the HE / EHT / UHR P160 subfield 1009 may be set to 2. This notifies STA 110 that it should transmit using a UHR TB PPDU. In this way, STA110 can determine the PPDU format and standard that its device should use based on the value of the HE / EHT / UHR P160 subfield 1009 contained in the received Trigger frame.

[0082] The HE / EHT / UHR P160 subfield 1009 can be used as primary information to identify the MCS table that STA110 should use. If the MCS tables specified in each standard differ, STA110 can determine that it should use the primary MCS table to identify the MCS that its device should use by specifying that its device should use UHR TB PPDU. In this way, by utilizing subfields that exist in legacy standards to notify primary information, it becomes unnecessary to add new subfields to the Trigger frame or to define new types of Trigger frames.

[0083] AP101 may also notify the first information using the Special User Info field. As shown in Figure 11B, the Special User Info field includes the PHY Version Identifier subfield 1112. As described above, the PHY Version Identifier subfield 1112 may be used to specify the type of PPDU that STA110 should use for transmission. For example, if the value of PHY Version Identifier subfield 1112 is set to 0, it may indicate that an EHT TB PPDU should be used. Also, if the value of PHY Version Identifier subfield 1112 is set to 1, it may indicate that a UHR TB PPDU should be used. In this way, AP101 can use the PHY Version Identifier subfield 1112 to notify STA110 of the standard to which the PPDU to be used conforms, and also notify STA110 of the MCS table to be used.

[0084] Areas commonly used by multiple STAs 110, such as the Common Info field 1005 or other subfields of the Special User Info field in the Trigger frame, may be used to notify the first information. For example, if a reserved area exists in the Common Info field 1005 or the Special User Info field, the first information may be notified using this reserved area. By using unused areas to identify the MCS table that the receiving communication device 100 should use, the MCS table to be used can be flexibly notified regardless of the correspondence between the standard and the MCS table. For example, in cases where a common MCS table is used in multiple standards, or where multiple different MCS tables are used in one standard, it may be better to notify the difference (version) of the MCS table rather than the difference in the standard. In this case, identification information assigned to each MCS table may be set as the first information. If no reserved area exists in the Common Info field 1005 or the Special User Info field, other subfields included in these fields may be repurposed to notify the first information. Additionally, new subfields for notifying the first information may be added, and new types of Trigger frames including areas for notifying the first information may be defined.

[0085] AP101 may notify STA110 of second information indicating the MCS corresponding to the MCS to be used using the User Info field 1011 of the Trigger frame. In this case, a 5-bit area may be provided in the User Info field 1011 as a subfield indicating the MCS index. Figure 11C shows an example of the configuration of the User Info field 1011. In Figure 11C, the same configuration as in Figure 11A is given the same reference number and its explanation is omitted. That is, the User Info field 1011 in the Trigger frame of Figure 11C differs from the User Info field 1011 in Figure 11A in that it includes a 5-bit UL UHR-MCS 1110. By configuring UL UHR-MCS1110 as a 5-bit area, it becomes possible to assign an MCS index to each of the MCSs defined in the IEEE 802.11bn standard. In Figure 11C, the UL DCM subfield 1105 in Figure 11A is used to configure UL UHR-MCS1110 as a 5-bit area. Other subfields may be used to configure UL UHR-MCS1110 as a 5-bit area. For example, the Reserved subfield 1108 may be used. Alternatively, UL UHR-MCS1110 may be configured as 4 bits, with the UL DCM subfield 1105 or other areas being used as a 1-bit extension area for notifying the MCS. In this case, an MCS can be associated with a combination of the 4-bit UL UHR-MCS1110 and the 1-bit extension area.

[0086] Thus, when STA110 transmits using a UHR TB PPDU, AP101 may use a Trigger frame to notify STA110 that it should use a first MCS table and the MCS index of the MCS to be used for generating the data. For example, AP101 may use the HE / EHT / UHR P160 subfield 1009 of the Trigger frame to notify STA110 that it should use a PPDU conforming to the first standard. Alternatively, AP101 may use the PHY Version Identifier 1112 of the Special User Info field of the Trigger frame to notify STA110 that it should use a PPDU conforming to the first standard. These fields are areas in the MAC frame body of the Trigger frame that are commonly used for multiple STA110s. AP101 can use these areas to notify STA110 that it should use the first MCS table. AP101 can also use the 5-bit UL UHR-MCS subfield in the User Info field to notify STA110 of the MCS index corresponding to the MCS that STA110 should use to generate the data signal.

[0087] (Configuration of the MCS Table) An example of the configuration of the first MCS table specified in the first standard and an example of the configuration of the second MCS table specified in the second standard will be described. The MCS table is a table that shows the correspondence between MCSs that can be used by the communication device 100 and MCS indexes that uniquely identify those MCSs within the MCS table. The MCS table may be composed of an MCS index (MCS index), a modulation scheme, and a coding rate. An example of the configuration of the second MCS table specified in the second standard (IEEE 802.11be standard) may be the MCS table shown in Figure 15, for example. The second MCS table may have other configurations. An example of the configuration of the first MCS table specified in the first standard (IEEE 802.11bn standard) is shown in Figure 27. The first MCS table shown in Figure 27 differs from the first MCS table in that it includes four additional MCSs: QPSK with a coding rate of 2 / 3, 16-QAM with a coding rate of 2 / 3, 16-QAM with a coding rate of 5 / 6, and 256-QAM with a coding rate of 2 / 3. Furthermore, the addition of these four MCSs results in a difference in the mapping between MCSs and MCS indices between the first and second MCS tables. For example, in the second MCS table, the MCS for the combination of 4096-QAM with a coding rate of 5 / 6 is assigned an MCS index value of 13. On the other hand, in the first MCS table, the MCS for the combination of 4096-QAM with a coding rate of 5 / 6 is assigned an MCS index value of 17. This is because, in the first MCS table, the table has been restructured so that the higher the data rate of each MCS, including the four added MCSs, the larger the MCS index value assigned. The data rate shown in Figure 27 is an example of the data rate when 26 tones of RU are assigned to STA110 and a PPDU consisting of OFDM symbols with a guard interval length of 0.8 μsec is transmitted in a single stream.

[0088] The four MCSs added in this example are MCSs that were not used in the legacy standard. By enabling the use of these MCSs, the throughput of the BSS can be increased. For example, suppose that in a communication device using the second MCS table, if a transmission using an MCS with a QPSK and coding rate of 3 / 4 fails, the next transmission uses an MCS with a QPSK and coding rate of 1 / 2. In contrast, a communication device using the first MCS table can use an MCS with a QPSK and coding rate of 2 / 3 in the next transmission if a transmission using an MCS with a QPSK and coding rate of 3 / 4 fails. This allows the use of an MCS with a data rate 1.5 times higher. In this way, by enabling the use of MCSs that were not used in the legacy standard, the overall throughput of the BSS can be increased.

[0089] Furthermore, as shown in Figure 27, by reconstructing the first MCS table based on the data rate of each MCS, the communication device 100 can efficiently select an appropriate MCS by referring to the first MCS table according to the conditions of the propagation channel. For example, suppose an MCS index is assigned to an added MCS regardless of its data rate. In this case, the process of selecting the next MCS to use in the communication device 100 if transmission fails in the most recent communication may become complicated. For example, the communication device 100 may identify the data rate of each MCS, search for an MCS with a lower data rate, and decide that it should be used. On the other hand, as shown in Figure 27, by assigning an MCS index to each MCS, including the added MCS, based on its data rate, the communication device 100 can select an MCS corresponding to the MCS index with one smaller value in the event of a transmission failure. In this way, the communication device 100 can efficiently select an MCS based on the MCS index in the MCS table.

[0090] Here, by assigning an MCS index based on the data rate to each MCS, including the added MCS, different MCSs will be assigned to the same MCS index between the first MCS table and the second MCS table. For example, in the second MCS table, the value of MCS index 13 is assigned to an MCS with a combination of 4096-QAM and a coding rate of 5 / 6. On the other hand, in the first MCS table, the value of MCS index 13 is assigned to an MCS with a combination of 256-QAM and a coding rate of 5 / 6. Therefore, when the communication device 100 supports both the first and second standards, it may not be possible to uniquely identify an MCS from the value of the MCS index. Accordingly, in this example, the communication device 100 first identifies the MCS table to be used to identify the MCS based on the standard to which the PPDU conforms, and then identifies the MCS associated with the MCS index obtained based on the identified MCS table.

[0091] Furthermore, the addition of multiple MCSs increases the number of required MCS indices. For example, while the maximum MCS index in Figure 15 was 13 when QPSK-DCM was excluded, the maximum MCS index in Figure 27 is 17. If the maximum MCS index is 13, it can be represented with 4 bits, but if the maximum MCS index is 16 or more, 5 bits or more are required. Therefore, the communication device 100 in this example is configured to have a 5-bit area for indicating the MCS index. With this configuration, the communication device 100 can appropriately notify the other communication device of the MCS it has used, and can select and communicate from a variety of MCSs according to the conditions of the propagation channel. As a result, the communication device 100 corresponding to the first standard can improve the overall BSS throughput using the added MCSs. Note that the first MCS table does not necessarily have to include all four MCSs mentioned above, and other MCSs may be added.

[0092] Figure 28 shows another example of the configuration of the first MCS table used in the first standard. This example shows a case where MCS can be used in combination with QPSK, 16-QAM, 64-QAM, 256-QAM, 1024-QAM, and 4096-QAM, and coding rates of 1 / 2, 2 / 3, 3 / 4, 5 / 6, and 7 / 8, respectively. In this case, each MCS is arranged in ascending order of the number of levels in the modulation scheme, and among MCSs with the same number of levels in the modulation scheme, they are arranged in ascending order of coding rate. Then, the smallest MCS index is associated with each arranged MCS in order from the beginning. In Figure 28, the maximum value of the MCS index is 31, so the communication device 100 can notify the other communication device of the MCS index used using a 5-bit area. According to the configuration in Figure 28, a wider variety of MCS can be used, so the communication device 100 can finely switch MCS according to the conditions of the propagation channel. This could potentially increase the overall throughput of the BSS.

[0093] Figure 29 shows another example of the configuration of the first MCS table used in the first standard. In this example, while maintaining the assignment of MCS indices to each MCS in the second MCS table, an MCS index is assigned to each additional MCS. For example, each additional MCS may be associated with an MCS index not used in the second MCS table. As an example, the MCS for QPSK and coding rate 2 / 3 is assigned an MCS index value of 14. Also, the MCS for 16-QAM and coding rate 2 / 3, 16-QAM and coding rate 5 / 6, and 256-QAM and coding rate 2 / 3 are assigned MCS index values ​​from 16 to 18, respectively. According to this example configuration, different MCS indices are not assigned to the same MCS between the first MCS table and the second MCS table. Therefore, a communication device 100 that supports both communication using the first standard and communication using the second standard can uniquely identify the MCS based on the value of the MCS index.

[0094] Figure 30 shows another example of the configuration of the first MCS table used in the first standard. In this example, while maintaining the assignment of MCS indices to MCS in the second MCS table, an MCS index is assigned to each additional MCS. In this configuration example, the same MCS index as other MCS is assigned to the additional MCS, and the added MCS is identified by an extended bit. For example, the MCS with QPSK and a coding rate of 2 / 3 is assigned an MCS index value of 1. Also, the MCS with 16-QAM and a coding rate of 2 / 3, 16-QAM and a coding rate of 5 / 6, and 256-QAM and a coding rate of 2 / 3 are assigned MCS index values ​​of 3, 4, and 8, respectively. All of these MCS indices are the same MCS indices that are assigned to other MCS in the second MCS table. Therefore, the communication device 100 cannot uniquely identify the associated MCS using only the MCS index. Therefore, an extension bit is provided to identify these MCSs. For example, the Reserved subfield or part of the Spatial Configuration subfield of the User field of UHR-SIG1201 may be used as an extension bit. Alternatively, the UL DCM subfield 1105 of the User Info field 1011 may be used as an extension bit. For example, a value of 1 may be set as the extension bit to identify an added MCS. In this way, the communication device 100 can uniquely identify an MCS by using a 4-bit MCS index and a 1-bit extension bit together.

[0095] The first MCS tables that can be used in the first standard are not limited to the examples above. For example, in Figure 27, a larger MCS index may be assigned to a lower data rate. Some of the MCS included in Figure 28 may be deleted, and other MCS may be added. In Figure 29, the MCS indices assigned to the added MCS may be configured to be contiguous. MCS not included in these tables may be added, and some of the MCS included in these tables may be deleted.

[0096] (Sequence between communication devices) An example sequence for data exchange between communication devices configured as described above will be explained. Figure 13 shows an example sequence for downlink data communication between AP101 and STA111 and STA112. AP101 and STA111 and STA112 are each assumed to support both communication using the first standard and communication using the second standard. Furthermore, AP101 is assumed to identify the standard that each STA corresponds to in the procedure for establishing a connection with STA111 and STA112. In addition, AP101 is assumed to identify that STA111 and STA112 each have the capability to use the first MCS table and the second MCS table, and to identify the MCS that each STA can use.

[0097] First, when AP101 detects that data destined for STA111 and STA112 has been accumulated in its transmit buffer, it initiates channel access. AP101 also determines the type of PPDU to use based on the data's destination. For example, AP101 may determine to use a UHR MU PPDU based on the fact that both STA111 and STA112 support communication using the first communication standard. AP101 also determines the MCS for generating data signals for each STA. For example, AP101 may determine which MCS to use to generate a data signal destined for STA111 from among the MCS available for STA111. AP101 may also determine which MCS to use to generate a data signal destined for STA112 from among the MCS available for STA112. AP101 then generates a UHR MU PPDU containing the generated data signals. For example, AP101 may set a value corresponding to the PHY version of the first standard in the PHY Version Identifier subfield of U-SIG705 of UHR-MU PPDU. AP101 may also set the MCS index value in the 5-bit MCS subfield of the User field associated with STA111 of UHR-SIG1201. In this case, the MCS index value may be the MCS index value in the first MCS table corresponding to the MCS used to generate the data signal destined for STA111. Similarly, AP101 may set the MCS index value in the 5-bit MCS subfield of the User field associated with STA112 of UHR-SIG1201. In this case, the value of the MCS index assigned in the first MCS table to the MCS used to generate the data signal destined for STA112 may be used as the value of the MCS index. If AP101 successfully accesses the channel, it transmits the generated UHR MU PPDU 1301.

[0098] When STA111 and STA112 receive the PPDU 1301 transmitted by AP101, they perform reception processing based on the information contained in the preamble signal. For example, STA111 and STA112 can determine that the received PPDU 1301 is a UHR MU PPDU based on the value set in the PHY Version Identifier subfield of the U-SIG 705 of the received PPDU 1301. Also, STA111 and STA112 can identify the MCS used to generate the data signal based on the value in the MCS subfield of the User field associated with their own device in STA111 of the UHR-SIG 1201. For example, STA111 and STA112 can determine from the PHY Version Identifier subfield that a first MCS table should be used. Then, STA111 and STA112 can use the first MCS table to identify the MCS from the MCS index shown in the MCS subfield of the User field associated with their own device. Based on the identified MCS, STA111 and STA112 demodulate the data signal destined for their own device and acquire the data. STA111 and STA112 each send acknowledgments 1302 and 1303 to AP101, respectively, indicating that the data has been successfully demodulated. The acknowledgments may be Block ACK frames or ACK frames, etc. Based on receiving acknowledgments from STA111 and STA112, AP101 completes the transmission process.

[0099] Figure 14 shows an example sequence when uplink data is communicated between AP101 and STA111 and STA112. First, AP101 obtains the data storage status from STA111 and STA112, respectively. For example, AP101 may notify STA111 and STA112 to report the data storage status by sending a Buffer Status Report Poll frame 1401. STA111 and STA112 report the data storage status to AP101. For example, STA111 and STA112 may notify Buffer Status Reports 1402 and 1403 in response to the Buffer Status Report Poll frame 1401. AP101 transmits a Trigger frame 1404 based on the data storage status of STA111 and STA112. For example, if both STA111 and STA112 are storing data, AP101 may transmit a Trigger frame 1404 addressed to both STA111 and STA112. In the Trigger frame 1404, AP101 may specify the type of PPDU that STA111 and STA112 should use and the MCS that should be used to generate the data signal. For example, AP101 may determine that a UHR TB PPDU should be used based on the fact that both STA111 and STA112 support communication using the first standard. In this case, AP101 may notify STA111 and STA112 that they should use the UHR TB PPDU using the HE / EHT / UHR P160 subfield 1009 of the Trigger frame 1404. AP101 may select the MCS that STA111 should use to generate the data signal from among the MCS available to STA111. AP101 may also select the MCS that STA112 should use to generate the data signal from among the MCS available to STA112. AP101 may notify STA111 and STA112, respectively, of the MCS that they should use to generate the data signal using the UL UHR-MCS subfield 1110 of the User Info field 1011 of the Trigger frame 1404.At this time, AP101 uses the first MCS table to identify the MCS index to be notified. When STA111 and STA112 receive the Trigger frame 1404, they identify the type of PPDU to be used for transmission by their own devices and the MCS to be used to generate the data signal. For example, STA111 and STA112 may determine that a UHR TB PPDU should be used based on the value set in the HE / EHT / UHR P160 subfield 1009 of the Trigger frame 1404. Alternatively, STA111 and STA112 may determine that the MCS to be used by their own devices to generate the data signal based on the MCS index set in the UL UHR-MCS subfield 1110 of the User Info field 1011 assigned to their own devices. At this time, STA111 and STA112 use the first MCS table to identify the MCS associated with the MCS index. STA111 and STA112 each transmit UHR TB PPDU 1405 and 1406. The data signal contained in UHR TB PPDU 1405 is generated using the MCS identified by STA111. The data signal contained in UHR TB PPDU 1406 is generated using the MCS identified by STA112. AP101 performs reception processing on the received UHR TB PPDU 1405 and 1406 and transmits an acknowledgment 1407 indicating that the reception processing was successful. Based on the fact that STA111 and STA112 have received the acknowledgment from AP101, the transmission process is completed.

[0100] As described above, according to this embodiment, the transmitting communication device 100 includes predetermined information in the preamble of the wireless frame for identifying the MCS from the MCS index included in the wireless frame. The predetermined information includes first information that can identify the MCS table to be used to acquire the data included in the wireless frame, and second information that indicates the MCS index corresponding to the MCS used to generate the data signal. The receiving communication device 100 acquires data based on the information acquired from the preamble of the received wireless frame. The receiving communication device 100 identifies the MCS table to be used from the first information included in the preamble, and uses this MCS table to identify the MCS used to generate the data from the MCS index shown in the second information. Based on the identified MCS, the receiving communication device 100 demodulates the data signal and acquires the data. With this configuration, the MCS table used to identify the MCS from the MCS index can be matched between the transmitting communication device 100 and the receiving communication device 100. This allows the communication device 100 to flexibly use multiple standards with different parts of the MCS table, making it possible to use MCSs that have not been used before, and thus improving the overall throughput of the BSS. The configuration of the frame and the fields and subfields contained in the frame used in this embodiment is illustrative and can be configured differently. For example, some fields and subfields contained in the frame may be omitted, and other fields and subfields may be included. Each frame, field, and subfield may be called by a different name. Also, some of the information contained in each field and subfield may be different. For example, other information may be included in the table used in the explanation, and some information may be omitted. (Other embodiments) This disclosure can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or storage medium, and one or more processors in the computer of that system or device read and execute the program.It can also be achieved by a circuit that performs one or more functions (for example, an ASIC).

[0101] The technical ideas derived from this disclosure are not limited to the exemplary embodiments disclosed, but are intended to encompass various modifications of the exemplary embodiments, or substitutions with equivalent structures or functions. The scope of the following claims should be interpreted in the broadest way to encompass all such modifications and equivalent structures and functions.

[0102] This application claims priority based on Japanese Patent Application No. 2024-160329, filed on 17 September 2024, and all of its contents are incorporated herein by reference.

Claims

1. A communication device capable of transmitting a wireless frame conforming to one or more standards included in the IEEE 802.11 standard series to another communication device, wherein at least a portion of a first correspondence between each of a plurality of Modulation and Coding Schemes (MCS) defined in a first standard included in the standard and an MCS index that uniquely identifies the MCS differs from a second correspondence defined in a second standard that was standardized prior to the first standard, and the communication device comprises: a preamble signal including a wireless frame including a preamble signal and a data signal, the preamble signal including first information that allows the other communication device to specify whether to use the first correspondence or the second correspondence to identify the MCS from the MCS index, and second information indicating the MCS index corresponding to the MCS used to generate the data signal; and a data signal generated using the MCS indicated by the first information and the second information, A communication device comprising: a transmission means for transmitting a wireless frame generated by the generation means to another communication device, wherein the generation means generates the wireless frame, the wireless frame containing the first information in the Universal Signal (U-SIG) field of the preamble signal.

2. The communication device according to claim 1, wherein the generation means sets information indicating the standard to which the wireless frame conforms as the first information.

3. The communication device according to claim 1 or 2, wherein the generating means generates a wireless frame, wherein, as second information, if the wireless frame conforms to the first standard, the value of the PHY Version Identifier field included in the U-SIG field is set to a value greater than 0, and if the wireless frame conforms to the second standard, the value of the PHY Version Identifier field is set to a value of 0.

4. The communication device according to any one of claims 1 to 3, wherein the first mapping includes one or more of the following: a first MCS with QPSK and coding rate 2 / 3, a second MCS with 16QAM and coding rate 2 / 3, a third MCS with 16QAM and coding rate 5 / 6, and a fourth MCS with 64QAM and coding rate 2 / 3, and the second mapping does not include any of the first MCS, the second MCS, the third MCS, or the fourth MCS.

5. The communication device according to any one of claims 1 to 4, wherein the value of the MCS index corresponding to a predetermined MCS in the first correspondence is different from the value of the MCS index corresponding to the predetermined MCS in the second correspondence.

6. The communication device according to any one of claims 1 to 5, wherein the first correspondence is configured such that the MCS with a lower data rate is assigned a smaller MCS index.

7. The communication device according to claim 4, wherein the first correspondence is configured such that an MCS index not used in the second correspondence is assigned to one or more of the first MCS, the second MCS, the third MCS, and the fourth MCS.

8. The communication device according to any one of claims 1 to 7, wherein the generating means generates the wireless frame which includes a region composed of five or more bits for indicating the second information.

9. A communication device capable of receiving wireless frames from other communication devices that conform to one or more standards included in the IEEE 802.11 standard series, wherein at least a portion of a first correspondence between each of a plurality of Modulation and Coding Schemes (MCS) defined in a first standard included in the standard and an MCS index that uniquely identifies the MCS differs from a second correspondence defined in a second standard that was standardized before the first standard, and the communication device comprises: receiving means for receiving a wireless frame including a preamble signal and a data signal; acquiring means for acquiring first information that allows the communication device to specify whether to use the first correspondence or the second correspondence in the preamble signal to identify the MCS from the MCS index, and second information indicating the MCS index corresponding to the MCS used to generate the data signal; and demodulating means for demodulating the data signal based on the MCS identified by the first information and the second information. The acquisition means is a communication device that acquires the first information from the Universal Signal (U-SIG) field in the preamble signal.

10. The communication device according to claim 9, wherein the acquisition means acquires information indicating the standard to which the wireless frame conforms as the second information, and the demodulation means identifies the MCS using the first correspondence if the wireless frame is a wireless frame conforming to the first standard, and identifies the MCS using the second correspondence if the wireless frame is a wireless frame conforming to the second standard.

11. The communication device according to claim 9 or 10, wherein, as the second information, if the wireless frame conforms to the first standard, a value greater than 0 is set as the value of the PHY Version Identifier field included in the U-SIG field, and if the wireless frame conforms to the second standard, a value of 0 is set as the value of the PHY Version Identifier field.

12. The communication device according to any one of claims 9 to 11, wherein the first correspondence includes one or more of the following: a first MCS with QPSK and coding rate 2 / 3, a second MCS with 16QAM and coding rate 2 / 3, a third MCS with 16QAM and coding rate 5 / 6, and a fourth MCS with 64QAM and coding rate 2 / 3, and the second correspondence does not include any of the first MCS, the second MCS, the third MCS, or the fourth MCS.

13. The communication device according to any one of claims 9 to 12, wherein the value of the MCS index corresponding to a predetermined MCS in the first correspondence is different from the value of the MCS index corresponding to the predetermined MCS in the second correspondence.

14. The communication device according to any one of claims 9 to 13, wherein the first correspondence is configured such that a smaller MCS index is assigned to an MCS with a lower data rate.

15. The communication device according to claim 12, wherein the first correspondence is configured such that an MCS index not used in the second correspondence is assigned to one or more of the first MCS, the second MCS, the third MCS, and the fourth MCS.

16. The communication device according to any one of claims 9 to 15, wherein the second information is represented using five or more bits.

17. A communication device capable of receiving wireless frames from another communication device conforming to one or more standards included in the IEEE 802.11 standard series, wherein at least a portion of a first correspondence between each of a plurality of Modulation and Coding Schemes (MCS) defined in a first standard included in the standard and an MCS index that uniquely identifies the MCS differs from a second correspondence defined in a second standard that was standardized prior to the first standard, and the communication device includes: determination means for determining which MCS the other communication device should use to generate the data signals included in the wireless frame when the other communication device transmits the wireless frame; first information that allows the other communication device to determine whether to use the first correspondence or the second correspondence to identify the MCS from the MCS index; and second information indicating the MCS index corresponding to the MCS determined by the determination means, and transmits a Trigger frame, A communication device comprising: receiving means for receiving a wireless frame from another communication device, which includes a data signal generated using an MCS identified by the first information and the second information, wherein the transmitting means transmits the Trigger frame, which includes the second information in a region of the MAC frame body that is commonly used for a plurality of the other communication devices.

18. A communication device capable of transmitting a wireless frame conforming to one or more standards included in the IEEE 802.11 standard series to another communication device, wherein at least a portion of a first correspondence between each of a plurality of Modulation and Coding Schemes (MCS) defined in a first standard included in the standard and an MCS index that uniquely identifies the MCS differs from a second correspondence defined in a second standard that was standardized prior to the first standard, and the communication device includes receiving means for receiving a Trigger frame including first information that allows the communication device to specify whether to use the first correspondence or the second correspondence to identify an MCS from an MCS index, and second information indicating the MCS index corresponding to the MCS that the communication device should use when generating a data signal, and transmitting means for transmitting a wireless frame containing a data signal generated using the MCS identified by the first information and the second information to the other communication device. The receiving means is a communication device that acquires the second information from a region of the MAC frame body included in the Trigger frame that is commonly used for multiple other communication devices.

19. A communication method performed by a communication device capable of transmitting a wireless frame conforming to one or more standards included in the IEEE 802.11 standard series to another communication device, wherein at least a portion of a first correspondence between each of a plurality of Modulation and Coding Schemes (MCS) defined in a first standard included in the standard and an MCS index that uniquely identifies the MCS differs from a second correspondence defined in a second standard that was standardized prior to the first standard, and the communication method generates a wireless frame including a preamble signal and a data signal, the preamble signal including first information that allows the other communication device to specify whether to use the first correspondence or the second correspondence to identify the MCS from the MCS index, and second information indicating the MCS index corresponding to the MCS used to generate the data signal, and a data signal generated using the MCS indicated by the first information and the second information, A communication method comprising transmitting the generated wireless frame to the other communication device, wherein the generation includes generating the wireless frame in which the second information is included in the Universal Signal (U-SIG) field of the preamble signal.

20. A communication method performed by a communication device capable of receiving wireless frames conforming to one or more standards included in the IEEE 802.11 standard series from other communication devices, wherein at least a portion of a first correspondence between each of a plurality of Modulation and Coding Schemes (MCS) defined in a first standard included in the standard and an MCS index that uniquely identifies the MCS differs from a second correspondence defined in a second standard that was standardized prior to the first standard, and the communication method comprises: receiving a wireless frame including a preamble signal and a data signal; obtaining first information in the preamble signal that allows the communication device to specify whether to use the first correspondence or the second correspondence to identify the MCS from the MCS index, and second information indicating the MCS index corresponding to the MCS used to generate the data signal; and demodulating the data signal based on the MCS identified by the first information and the second information. The acquisition described above is a communication method that includes acquiring the second information from the Universal Signal (U-SIG) field in the preamble signal.

21. A communication method performed by a communication device capable of receiving wireless frames from other communication devices that conform to one or more standards included in the IEEE 802.11 standard series, wherein at least a portion of a first correspondence between each of a plurality of Modulation and Coding Schemes (MCS) defined in a first standard included in the standard and an MCS index that uniquely identifies the MCS differs from a second correspondence defined in a second standard that was standardized prior to the first standard, and the communication method comprises: determining the MCS that the other communication device should use to generate the data signals included in the wireless frame when the other communication device transmits the wireless frame; transmitting a Trigger frame that includes first information that allows the other communication device to determine whether to use the first correspondence or the second correspondence to identify the MCS from the MCS index; and second information indicating the MCS index corresponding to the MCS determined by the determination, A communication device having the ability to receive from another communication device a wireless frame containing a data signal generated using an MCS identified by the first information and the second information, wherein the ability to transmit includes transmitting the Trigger frame containing the second information in a region of the MAC frame body that is commonly used for a plurality of the other communication devices.

22. A communication method performed by a communication device capable of transmitting a wireless frame conforming to one or more standards included in the IEEE 802.11 standard series to another communication device, wherein at least a portion of a first mapping between each of a plurality of Modulation and Coding Schemes (MCS) defined in a first standard included in the standard and an MCS index that uniquely identifies the MCS differs from a second mapping defined in a second standard that was standardized prior to the first standard, and the communication method comprises: receiving a Trigger frame containing first information that allows the communication device to specify whether to use the first mapping or the second mapping to identify an MCS from an MCS index, and second information indicating the MCS index corresponding to the MCS that the communication device should use when generating a data signal; and transmitting a wireless frame containing a data signal generated using the MCS identified by the first information and the second information to the other communication device. The receiving of the above-mentioned information includes obtaining the second information from a region of the MAC frame body included in the Trigger frame that is commonly used for multiple other communication devices.

23. A program for causing a computer to function as each of the means of the communication device described in any one of claims 1 to 18.

24. A communication device capable of transmitting a wireless frame conforming to one or more standards included in the IEEE 802.11 standard series to another communication device, comprising a transmission means for transmitting an Ultra High Reliability (UHR) Multi-user (MU) PLCP Protocol Data Unit (PPDU) including a preamble and a data field, wherein the preamble includes a Universal Signal (U-SIG) field with a value of 1 set in the PHY Version Identifier field, and an Ultra High Reliability Signal (UHR-SIG) field containing first information that identifies a Modulation and Coding Scheme (MCS) indicating the modulation scheme and coding rate of the data field, The first information is transmitted to the other communication device using a total of 5 bits in the UHR-SIG, and the modulation scheme is shown to be Quadrature Phase Shift Keying (QPSK) and the coding rate is 2 / 3 by setting a value of 1 in a specific bit of the total 5 bits and setting a value of 1 using the other 4 bits; the modulation scheme is shown to be 16 Quadrature Amplitude Modulation (QAM) and the coding rate is 2 / 3 by setting a value of 1 in a specific bit and setting a value of 3 using the other 4 bits; and the modulation scheme is shown to be 16 QAM and the coding rate is 5 / 6 by setting a value of 1 in a specific bit and setting a value of 4 using the other 4 bits.

25. The communication device according to claim 24, wherein the transmitting means further transmits an Extremely High Throughput (EHT) MU PPDU, the preamble of which includes the U-SIG field with a value of 0 set in the PHY Version Identifier field, and the Extremely High Throughput Signal (EHT-SIG) field containing second information that identifies the MCS indicating the modulation scheme and coding rate of the data field, and the second information is transmitted to the other communication device using a total of 4 bits in the EHT-SIG.

26. The communication device according to claim 25, characterized in that the total of 4 bits for storing the second information are provided in the User field of the EHT-SIG, and the total of 5 bits for storing the first information are provided in the User field of the UHR-SIG.

27. A communication device capable of communicating with other communication devices using wireless frames conforming to one or more standards included in the IEEE 802.11 standard series, comprising a transmission means for transmitting a Trigger frame containing specific information that identifies a Modulation and Coding Scheme (MCS) indicating the modulation scheme and coding rate to be used by the other communication device when transmitting the wireless frame, wherein the specific information is transmitted to the other communication device using a total of 5 bits in the User Info field of the MAC frame body constituting the Trigger frame, and the value of 1 is set in a specific bit of the total 5 bits and the value of 1 is set in the other 4 bits to indicate that the modulation scheme is Quadrature Phase Shift Keying (QPSK) and the coding rate is 2 / 3, and the value of 1 is set in the specific bit and the value of 3 is set in the other 4 bits to indicate that the modulation scheme is 16 Quadrature A communication device in which Amplitude Modulation (QAM) is shown to have a coding rate of 2 / 3, and the modulation scheme is shown to be 16QAM with a coding rate of 5 / 6 by setting a value of 1 to a specific bit and setting a value of 4 using the other 4 bits.

28. A communication device capable of communicating with other communication devices a wireless frame conforming to one or more standards included in the IEEE 802.11 standard series, comprising receiving means for receiving a Trigger frame containing specific information that identifies a Modulation and Coding Scheme (MCS) indicating the modulation scheme and coding rate to be used when the communication device transmits the wireless frame, wherein the specific information is transmitted from the other communication device using a total of 5 bits in the User Info field of the MAC frame body constituting the Trigger frame, and the value of 1 is set in a specific bit of the total 5 bits and the value of 1 is set in the other 4 bits to indicate that the modulation scheme is Quadrature Phase Shift Keying (QPSK) and the coding rate is 2 / 3, and the value of 1 is set in the specific bit and the value of 3 is set in the other 4 bits to indicate that the modulation scheme is 16 Quadrature A communication device in which Amplitude Modulation (QAM) is shown to have a coding rate of 2 / 3, and the modulation scheme is shown to be 16QAM with a coding rate of 5 / 6 by setting a value of 1 to a specific bit and setting a value of 4 using the other 4 bits.

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