COMMUNICATION DEVICE AND COMMUNICATION METHOD

Abstract

At an access point (AP) (100), a trigger frame generator unit (104) generates a trigger signal that commands the transmission of an uplink signal. The trigger signal includes a terminal information field with a terminal ID subfield and a resource unit distribution information subfield. A wireless transmit / receive unit (106) transmits a trigger signal. If the trigger signal includes a first terminal information field indicating one or more successive random access resource units, the trigger frame generator unit (104) sets an unused ID in the first terminal information field, which is not used as a terminal ID.

Description

COMMUNICATION DEVICE AND COMMUNICATION METHOD nnzrnn / cznz / E / YiAi Field of Invention This description refers to a communication device and a method of communication. Background of the Invention Within the IEEE (Institute of Electrical and Electronics Engineers) 802.11 working groups, a task group ax has been working to establish the technical specifications for IEEE 802.11ax (hereafter referred to as llax) as a successor to the 802.11ac standard. llax introduces OFDMA (Orthogonal Frequency Division Multiple Access) based on random access (RA). An access point (AP, also called a base station) transmits to a plurality of terminals (also called STAs (stations)) associated with the AP, a control signal to instruct them to transmit an uplink OFDMA signal (hereafter, this control signal is referred to as an actuator frame). In the activator box, a common information field and a user information field are defined. The common information field includes information that is shared among a plurality of OFDMA multiplexed terminals. The user information field includes information Ref. 344473 specifies each of the terminals multiplexed by OFDMA (see for example, NPL 1 and NPL 4). The common information field includes an actuator type subfield that specifies the actuator type that indicates an actuator box type (a type of signal instructed to a terminal, by the AP, for transmission) (see, for example, NPL 2 and NPL 3). The user information field includes a subfield AID 12 used for reporting an association ID (AID), which is an ID uniquely assigned to a terminal when the terminal is associated. Hereafter, planned access denotes a method in which an AID assigned to a specific terminal is communicated to the terminal, thereby distributing a frequency resource unit (RU) to the terminal. Furthermore, in llax, it is agreed that by setting one of the unused AIDs to 0, each terminal is informed that a frequency resource (RU) specified in a RU distribution subfield within a user information field is one RU for one RA (RA-RU) (for example, see NPL 1). Furthermore, in compliance with llax, it is agreed that an activator box could include a new user information field (called a modified user information) dedicated to RA (NPL 5). In the modified user information, a user information field nnzrnn / cznz / E / YiAi specifies one or more contiguous RA-RUs for a terminal. List of Citations: Unpatented Literature NPL 1: IEEE 802.Il-15 / O132rl7 Specification Framework for TGax NPL 2: IEEE 802.11-16 / 0024rl Proposed TGax draft specification NPL 3: IEEE 802.11-16 / 0806r0 HE Variant HT Control Buffer Status Report NPL 4: IEEE 80211-16 / 0617rl Remaining Topics in Power Control NPL 5: IEEE 802.11-16 / 1516rl CIDs for: Section 9.3.1.23 Random Access CIDs NPL 6: IEEE 802.11-16 / 0725r3 CIDs for: Trigger Frame Format Comment Resolulion - Type Dependent Per user Information section 9.3.1.23 NPL 7: IEEE 802.11-16 / 0938rl Resolution for CID 1589, 1590, 2668, and 2669 on Multi-TID Aggregation in Sub-clause 25.10.4. Summary of the Invention However, there has not been enough discussion regarding how to apply the modified user information to the trigger box. In one aspect, the present description provides a communication apparatus and a method of communication with the ability to properly set the modified user information in the activator box. According to one aspect of the present description, a communication apparatus includes a trigger signal generator that generates a trigger signal instructing an uplink signal transmission; the trigger signal includes a terminal information field that includes a terminal ID subfield and a resource unit distribution information subfield; in a case where the trigger signal includes a first terminal information field that specifies one or more contiguous resource units for random access, an unused ID is established that will not be used as a terminal ID in the terminal ID subfield in the first terminal information field; and a transmitter that transmits the generated trigger signal. The general or specific modalities could be implemented as a system, an apparatus, a method, an integrated circuit, a computer program or a storage medium or any combination of a system, an apparatus, a method, an integrated circuit, a computer program and a storage medium. According to one aspect of this description, it is possible to properly set the modified user information in the activator box. The additional benefits and advantages of the described modalities nnzrnn / cznz / E / YiAi will be clear from the description and figures. These benefits and / or advantages could be obtained individually from the various modalities and features described and shown in the figures, none of which need to be provided in order to obtain one or more of these benefits and / or advantages. Brief Description of the Figures Figure 1 shows a diagram illustrating a trigger box format. Figure 2 shows a diagram illustrating a common information field format for a trigger box. Figure 3 shows a diagram illustrating one type of trigger box. Figure 4 shows a diagram illustrating a format of a user information field of a trigger box. Figure 5 shows a diagram illustrating a user information field format of a trigger-dependent user information field. Figure 6A shows a diagram illustrating a format of a modified user information field of a trigger box. Figure 6B shows a diagram illustrating an example of an RA-RU specified by a modified user information field nnzrnn / cznz / E / YiAi. Figure 7 shows a block diagram illustrating an example of a partial configuration of an AP according to a first modality. Figure 8 shows a block diagram illustrating an example of an AP configuration according to the first mode. Figure 9 shows a block diagram illustrating a terminal configuration according to the first mode. Figure 10 shows a diagram illustrating an example (a specific example 1-1) of an RA-RU specified by modified user information according to the first modality. Figure 11 shows a diagram illustrating an example (a specific example 1-2) of an RA-RU specified by modified user information according to the first modality. Figure 12 shows a diagram illustrating an example (a specific example 1-2) of an RA-RU specified by modified user information according to the first modality. Figure 13 shows a diagram illustrating an example (a specific example 1-2) of an RA-RU specified by user information according to the first nnzrnn / cznz / E / YiAi modality. Figure 14 shows a diagram illustrating an example (a specific example 2) of an RA-RU specified by user information according to the first modality. Figure 15 shows a diagram illustrating an example (a specific example 2) of an RA-RU specified by user information according to the first modality. Figure 16 shows a diagram illustrating an example (a specific example 2-1) of an RA-RU specified by user information according to the first modality. Figure 17 shows a diagram illustrating an example (a specific example 2-2) of an RA-RU specified by modified user information according to the first modality. Figure 18 shows a diagram illustrating an example (a specific example 2-2) of an RA-RU specified by modified user information according to the first modality. Figure 19 shows a block diagram illustrating an example of an AP configuration according to a second mode. nnzrnn / cznz / E / YiAi Figure 20 shows a block diagram illustrating an example of a terminal configuration according to the second mode. Figure 21 shows a diagram illustrating an example (a specific example 1) of an RA-RU specified by user information according to the second modality. Figure 22 shows a diagram illustrating an example (a specific example 2) of an RA-RU specified by user information according to the second modality. Figure 23 shows a diagram illustrating an example (specific example 3) of an RA-RU specified by user information according to the second modality. Figure 24 shows a diagram illustrating an example of an RA-RU specified by user information according to another modality. Figure 25 shows a diagram illustrating an example of an activator box configuration according to another modality. Detailed Description of the Invention The modalities described herein are detailed below with reference to the figures. In the modalities described below, similar elements nnzrnn / cznz / E / YiAi are denoted by similar reference symbols, and their duplicate description is omitted. First modality Activator Box Figure 1 shows a diagram illustrating an example of an actuator frame format that is under discussion in llax. The actuator frame defines a common information field that includes information common to a plurality of OFDMA multiplexed terminals and a user information field that includes information specific to each of the OFDMA multiplexed terminals (see, for example, NPL 1). Figure 2 shows a diagram illustrating an example of a common information field format for an actuator box (see, for example, NPL 1). An actuator type subfield specifies an actuator type. Figure 3 illustrates the defined actuator types (see, for example, NPL 2). Defining an additional actuator type to instruct a terminal to report transmission dampening information (hereafter referred to as the Damping Status Report Survey (BSRP)) in addition to the defined actuator types shown in Figure 3 (see, for example, NPL 3) is under discussion. A trigger-dependent common information subfield could include the appropriate (dependent) common terminal information for a specific actuator type. nnzrnn / cznz / E / YiAi Figure 4 shows a diagram illustrating an example of a user information field format for an actuator box (see, for example, NPL 1 and NPL 4). In the format shown in Figure 4, the size of the target RSSI subfield, which was not yet determined in NPL 1, is set to seven bits, as suggested in NPL 4. An AID 12 subfield is used to report an AID. When the AID is set to 0, it indicates that the RU specified in the user information field is an RA-RU (see, for example, NPL 1). An actuator-dependent user information subfield could include the appropriate terminal-specific (dependent) information for a specific actuator type. From this point forward, a user information field that specifies a radio resource for a terminal in RU units is denoted as normal user information to distinguish it from modified user information. Normal user information and modified user information could be referred to generically as user information. Furthermore, in llax, a basic trigger is defined as one of the trigger types. With a basic trigger, the uplink signal format is not limited to specific formats (see, for example, Figure 3). As a response to a basic trigger, both a response using planned access and a response using random access are permitted. In a case where the trigger type is the basic trigger type, the trigger-dependent user information subfield of the user information field includes information (receive information) indicating a restriction on the uplink signal transmission, as shown in Figure 5 (see, for example, NPL 6 and NPL 7). More specifically, as shown in Figure 5, a user information subfield dependent type includes a 2-bit MPDU MU separation factor indicating a minimum permissible range of an MPDU (a MAC protocol data unit) that can be processed by the AP, a 3-bit TID aggregate limit indicating a maximum number of TIDs included in the MPDU, a 1-bit AC preference level that functions as a flag indicating whether an access category (AC, a type of transmission data) recommended by the AP is specified, and a 2-bit preferred AC that indicates a parameter which, in turn, indicates an AP-recommended AC. These are parameters for using an A-MPDU (aggregate MAC protocol data unit), which is an aggregate of multiple MPDUs, as an uplink signal in response to a trigger frame, or parameters for specifying the AC that will be transmitted. Modified User Information Figure 6A shows a diagram illustrating an example of a modified user information format. In the trigger box that uses normal user information, an arbitrary RU is specified using a user information field. That is, in the trigger box that uses normal user information to specify a plurality of RA-RUs, a plurality of user information fields are used. In contrast, in modified user information, the specified RU locations are limited to a continuous band. This makes it possible to specify a plurality of RUs using a single modified user information field. For example, in the modified user information shown in Figure 6A, a RU distribution subfield specifies a starting RU location within a continuous band of RA-RUs the size of one RU (see Figure 6B). Furthermore, in modified user information, when the number of spatially multiplexed RA-RU streams is limited to 1 (i.e., MIMO is not used), a SS distribution subfield shown in Figure 6A does not specify the number of spatially multiplexed streams but rather the number of RA-RUs (the number of contiguous RUs), starting at the RA-RU reported by the RU distribution subfield (see Figure 6B).It is observed that the RU size of each RA-RU is specified by the nnzrnn / cznz / E / YiAi RU size reported by the RU distribution subfield. The information described in the encoding type, MCS, DCM, and RSSI subfields of the modified user information target shown in Figure 6A are common to a plurality of RA-RUs specified by the RU distribution and the SS distribution. Furthermore, in the modified user information, as shown in Figure 6A, the trigger-dependent user information subfield is removed. In the trigger box that uses the modified user information, the trigger-dependent common information subfield is removed. As a result, the size of the trigger box is reduced. As described above, in modified user information, a portion of the parameters specified by normal user information is shared by a plurality of RUs (a plurality of terminals) so that one or more contiguous RA-RUs are specified by a user information field, thereby achieving a reduction in the size of the trigger box. The modified user information has been described previously. According to the present description, a method of applying the modified user information nnzrnn / cznz / E / YiAi to the activator box is described below. For example, to apply the modified user information, a new trigger type specifying RA transmission (hereafter referred to as the RA trigger) could be added to the reserved trigger type subfield shown in Figure 3. When the RA trigger is specified as the trigger type, using the modified user information allows for a reduction in the trigger box size. Furthermore, when the RA trigger is specified as the trigger type, deleting the trigger-dependent common information subfield and the trigger-dependent user information subfield can further reduce the trigger box size. However, the description of the modified user information using the RA trigger described above uses (consumes) the reserved field of the trigger type, resulting in a reduction in the space of an additional extension of the standard. Furthermore, the RA trigger is allowed to be specified only by modified user information, and thus, only one group of contiguous RUs can be specified by a parameter. Therefore, in the case where a portion of the RUs in a system band are expected to experience performance degradation (for example, a RU located near a DC or a RU where interference is observed), it is necessary to set robust elastic high-error parameters (for example, the MCS) for all RUs specified by the modified user information, and thus, a reduction in performance occurs. In view of the above, the present description provides a method of describing a plurality of RARUs by means of a small-sized trigger box that uses modified user information while maintaining future extension of the trigger type (i.e., without adding a new trigger type such as an RA trigger, or similar) and a method of describing a specific parameter per RU even in a case if modified user information were employed. Wireless Communication System Configuration In this configuration, a communication system includes an AP 100 (radio transmitting apparatus) and a terminal 200 (radio receiving apparatus). The AP 100 transmits an activation frame that instructs the RA transmission to the terminal 200. The terminal 200 receives the activation frame and transmits an RA to the AP 100 using a resource specified in the activation frame. Figure 7 shows a block diagram that partially illustrates an AP 100 configuration according to the present mode. In the AP 100 shown in Figure 7, an actuator frame generator 104 generates an actuator frame (an actuator signal) that instructs the transmission of an uplink signal. A radio transceiver 106 transmits the actuator frame. In a case where the actuator frame includes a modified user information field (a first terminal information field) that specifies one or more contiguous RA-RUs, the actuator frame generator 104 sets an unused AID, which will not be used as an AID (a terminal ID), in an AID subfield 12 (the terminal ID subfield) in the modified user information field. AP Configuration Figure 8 shows a block diagram illustrating an AP 100 configuration according to the present mode. AP 100 generates a trigger frame (a trigger signal) to instruct terminal 200 to transmit an uplink signal (for example, an RA signal) and to forward the generated trigger frame to terminal 200. In Figure 8, the AP 100 includes a resource controller RA 101, a user information controller 102, an AID controller 103, a trigger frame generator 104, a transmit signal modulator 105, a radio transmitter / receiver 106, an antenna 107, a receive signal demodulator 108, and a quality estimator 109. The radio transmitter / receiver 106 includes a transmitter and a receiver unit. The resource controller RA 101, the user information controller 102, the AID controller 103, the trigger frame generator 104, and the quality estimator 109 together form a media access control (MAC) unit. The RA 101 resource controller determines the band to be distributed to the RA-RU within a system band based on the reception quality for each RU with a predetermined output size of the quality estimator 109. The RA 101 resource controller outputs RA resource information indicating the band to which the RA-RU will be distributed to the user information controller 102 and the trigger frame generator 104. The RA resource information includes, for example, information associated with the RA-RU distributed within the system band, control information for generating the RA signal (the encoding type, MCS, DCM, SS distribution, and the target RSSI included in the user information field), and / or similar information. For example, for a RU with poor reception quality, such as one that overlaps with a band used by another service in the system band, one that corresponds to a DC frequency in a baseband when demodulated, one subject to strong relative interference, or similar situations, the RA resource controller 101 could apply a high-error elasticity MCS (e.g., BPSK) or a relatively high target RSSI level (e.g., -60 dBm).For another RU subject to relatively low interference, the RA 101 resource controller could apply an MCS (e.g., 16QAM) that provides higher transmission efficiency or a target RSSI level (e.g., -70 dBm) that causes even less interference to another terminal. The user information controller 102 controls the user information field included in the trigger box based on the RA resource information output from the RA resource controller 101 and outputs the control result to the trigger box generator 104. More specifically, user information controller 102 determines which user information field format (modified user information or normal user information) will be used and which RA-RU will be specified by the user information field. For example, when modified user information is used, user information controller 102 determines which RA-RUs to specify in the RU distribution and in the SS distribution of the user information field specifies a parameter that is common to these RA-RUs. On the other hand, when normal user information is used, user information controller 102 determines which RA-RU to specify in the user information field and specifies a single parameter associated with the RA-RU. nnzrnn / cznz / E / YiAi The AID 103 controller determines an AID (the information described in the AID 12 subfield of the trigger box) to specify a format for the user information field (either modified user information or normal user information). The AID 103 controller outputs the AID information indicating the determined AID to the trigger box generator 104. For example, the AID 103 controller could set, as the AID that specifies the RA-RU, an unused AID (in the descriptions for llax, one of AID = 0.2008-4094) that will not be used as a specific AID per terminal for planned access. Details of the AID definition for specifying the format of the user information field will be described later. The trigger frame generator 104 (trigger signal generator) generates a trigger frame to instruct terminal 200 to perform an RA transmission (e.g., an OFDMA-based RA transmission) (see, for example, Figures 1, 2, 4, and 6A). More specifically, based on the output information from the user information controller 102, the trigger frame generator 104 sets, in the respective subfields of the user information field, the parameters indicated by the RA resource information output from the RA resource controller 101. For example, in a case where modified user information is used, based on the RA resource information (the RA-RU distribution) output from RA resource controller 101, the trigger frame generator 104 establishes a starting RU location and RU size for the RA-RUs located in a continuous band in the RU distribution subfield and establishes the number of contiguous RA-RUs in the SS distribution subfield. On the other hand, in the case where normal user information is used, based on the RA resource information (the RA-RU distribution) output from RA resource controller 101, the trigger frame generator 104 establishes a starting location and RU size for the RA-RU in the RU distribution subfield. Furthermore, based on the output information from the AID controller 103 and the output information from the user information controller 102, the trigger box generator 104 sets an AID that corresponds to a format of the user information field in the AID subfield 12 of the trigger box. Then, the trigger frame generator 104 outputs the generated trigger frame (the trigger signal) to the transmit signal modulator 105. The transmit signal modulator 105 performs an encoding and modulation process on the trigger frame output from the trigger frame generator 104. In addition, the transmit signal modulator 105 adds, to the modulated nnzrnn / cznz / E / YiAi signal, control signals (also called preamble) such as a pilot signal used in frequency synchronization and timing synchronization at a receiving end (terminal 200), a channel estimation signal and / or similar, thereby generating a radio frame (a transmit signal), and the transmit signal modulator 105 outputs the resulting radio frame (the transmit signal) to the radio transmitter / receiver 106. Radio transmitter / receiver 106 performs a predetermined radio transmission process, including a D / A conversion, an up-frequency conversion to a carrier frequency, and the like, on the radio frame (the transmit signal) output of the transmit signal modulator 105. Radio transmitter / receiver 106 then transmits the resulting signal, subjected to the radio transmission process, to terminal 200 via antenna 107. Radio transmitter / receiver 106 receives a transmitted signal from terminal 200 via antenna 107 and performs a predetermined radio reception process, including down-conversion to a baseband frequency, an A / D conversion, and the like, on the received signal. Radio transmitter / receiver 106 then outputs the resulting signal, subjected to the radio reception process, to the receive signal demodulator 108. The receiver signal demodulator 108 extracts a radio frame nnzrnn / cznz / E / YiAi by performing autocorrelation or similar processes on the output signal of the radio transmitter / receiver 106 and outputs the extracted radio frame to the quality estimator 109. Quality estimator 109 estimates the reception quality of each RU with the predetermined size by using the pilot signal included in the radio box coming out of the receive signal demodulator 108 and outputs the estimation result to resource controller RA 101. Terminal Configuration Figure 9 shows a block diagram illustrating a configuration of terminal 200 according to the present mode. Terminal 200 receives the trigger frame that instructs an RA transmission from AP 100, then randomly selects one RU from the RA-RUs specified in the trigger frame and transmits an RA signal to AP 100. In Figure 9, terminal 200 includes an antenna 201, a radio receiver / transmitter 202, a receive signal demodulator 203, an actuator frame decoder 204, an AID controller 205, a resource determination unit RA 206, a generator RA 207, and a transmit signal modulator 208. The radio receiver / transmitter 202 includes a transmitter and a receive unit. The AID controller 205, the resource determination unit RA 206, and the generator RA 207 together form an access controller (MAC). Radio receiver / transmitter 202 receives the trigger frame instructing the RA transmission from AP 100 via antenna 201 and performs a predetermined radio reception process, including baseband downconversion, A / D conversion, and similar operations, on the received signal. Radio receiver / transmitter 202 then outputs the resulting radio reception signal to the receive signal demodulator 203. Radio receiver / transmitter 202 performs a predetermined radio transmission process, including D / A conversion, carrier frequency upconversion, and similar operations, on the output signal from the transmit signal modulator 208, described below. Radio receiver / transmitter 202 then transmits the resulting radio transmission signal to AP 100 via antenna 201. The receive signal demodulator 203 extracts a radio frame (an actuator frame) by performing autocorrelation processing, or similar, on the output signal from the radio receiver / transmitter 202 and outputs the resulting extracted radio frame (the actuator frame) to the actuator frame decoder 204. The trigger frame decoder 204 detects the nnzrnn / cznz / E / YiAi format of the user information field in the trigger frame output from the receive signal demodulator 203, then decodes the trigger frame and outputs the resulting decoded trigger frame to the RA resource determination unit 206. The AID 205 controller operates similarly to the AID 103 controller of the AP 100. More specifically, the AID 205 controller determines an AID (the information described in the AID 12 subfield of the trigger box) to specify a format (either modified user information or normal user information) for the user information field. The AID 205 controller then outputs the AID information indicating the determined AID to the RA 206 resource determination unit. Details of the AID definition used to specify the user information field format will be described later. Based on the AID output information from the AID controller 205 and the information described in the trigger box output from the trigger box decoder 204, the RA resource determination unit 206 determines the RA-RU and control information to generate an RA signal. The RA resource determination unit 206 outputs the determined control information to generate an RA-RU and an RA signal to the RA generator 207. More specifically, based on the information nnzrnn / cznz / E / YiAi AID, the RA 206 resource determination unit identifies the format (modified user information or normal user information) of the user information field that corresponds to the AID included in the AID 12 subfield of the trigger box out of the trigger box decoder 204. In a case where the format of the user information field is modified user information, the resource determination unit RA 206 identifies the starting location and RU size of the RA-RUs of the RU distribution subfield, then identifies the number of RA-RUs (the number of contiguous RUs) of the SS distribution subfield, then applies other parameters specified in the respective subfields of the modified user information field, in common, to the plurality of RA-RUs and determines an RA-RU by randomly selecting one from the plurality of RARUs. On the other hand, in the case where the format of the user information field is normal user information, the RA 206 resource determination unit identifies the starting location and RU size of an RA-RU from the RU distribution subfield and applies other parameters specified in the respective subfields (including the SS distribution subfield) of the normal user information field, individually, to an RA-RU. Based on the control information generated by the RA nnzrnn / cznz / E / YiAi RU and the RA signal output from the RA resource determination unit 206, the RA generator 207 generates an RA signal that includes the terminal ID and the transmission information (the data or control information, or the like) associated with terminal 200 and outputs the resulting RA signal to the transmission signal modulator 208. The transmit signal modulator 208 performs the encoding / modulation on the RA signal. The transmit signal modulator 208 adds, to the modulated signal, a control signal (preamble) such as a pilot signal used in frequency synchronization and timing synchronization in AP 100, a channel estimation signal, and / or similar signals, thereby generating a radio frame (a transmit signal). The transmit signal modulator 208 outputs the resulting radio frame (the transmit signal) to the radio receiver / transmitter 202. Note that the RA signal is frequency-mapped to the RARU indicated by the information determined by the RA resource determination unit 206. AP 100 and Terminal 200 Operations The operations of AP 100 and Terminal 200 in accordance with this modality are described in detail below. The AP 100 (the trigger box generator 104) sets an unused AID in the AID 12 subfield (the terminal ID subfield) of the modified user information that nnzrnn / cznz / E / YiAi specifies one or more contiguous RA-RUs in the trigger box, thereby notifying terminal 200 that the user information field that includes the unused AID is the modified user information. It is noted that the unused AID is a terminal-specific AID for planned access (i.e., a planned AID assigned to terminal 200) (in the present llax descriptions, the unused AID is either 0 or one of 2008-4094). As described above, by specifying, using an unused AID, that modified user information will be employed, it is possible to specify a plurality of RA-RU using modified user information in the small-sized trigger box while maintaining the future extent of the trigger type (i.e., without adding an RA trigger again as one of the trigger types). Specific examples 1 and 2 of the methods for describing the format of the user information field using an unused AID are described below. Specific Example 1 In specific example 1, only an unused AID is used to specify an RA-RU. In other words, the AID 103, 205 controller determines an unused AID to specify modified user information. For example, the AID 103, 205 controller determines that AID = 0 is the unused AID to specify the modified ID of user nnzrnn / cznz / E / YiAi. That is, the trigger box generator 104 sets AID = 0 (the unused AID) in the AID 12 subfield, thereby informing terminal 200 that the user information field containing the AID 12 subfield is in modified user information format. It is observed that in specific example 1, the description of a RA-RU using normal user information is not provided. That is, in specific example 1, any RA-RU is specified by the modified user information. For example, the trigger frame generator 104 could establish a plurality of modified user information to make it possible to individually set parameters for the respective modified user information. That is, in specific example 1, a small trigger frame containing modified user information is used. This makes it possible to achieve an operation similar to the distribution operation of an RA-RU using normal user information (i.e., by individually adjusting each RU). Note that in specific example 1, in RA transmission, the number of multiplexing spatial levels is limited to 1 (without MIMO). Specific examples 1-1 and 1-2 of specific example 1 are described below for a case where the modified user information is specified using an unused AID (AID = 0). nnzrnn / cznz / E / YiAi Specific Example 1-1 In the specific example 1-1, the AP 100 trigger box generator 104 sets modified user information in a trigger box. More specifically, as in the example shown in Figure 10, the trigger box generator 104 sets an AID in the AID 12 subfield of modified user information, such that AID = 0, which is an unused AID, thereby informing terminal 200 that the user information field that includes this AID 12 subfield is the modified user information. That is, the trigger frame generator 104 establishes a RU start location and RU size for a plurality of RA-RUs in the RU distribution subfield shown in Figure 10 and establishes, in the SS distribution subfield, not the number of spatially multiplexed flows, but the number of contiguous RA-RUs. For example, in a case where a value taken in the SS distribution subfield is 0-63 bits (6 bits), it is permissible to report, using the SS distribution subfield, the number of contiguous RA-RUs in the range of 1-64. This makes it possible for AP 100 to specify to any terminal 200 one of the contiguous RUs that include 1-64 RUs by means of modified user information. In the example shown in nnzrnn / cznz / E / YiAi Figure 10, seven contiguous RA-RUs (the contiguous RUs 7) are specified by modified user information. In the specific example 1-1, as described above, all RA-RUs are specified using modified user information, and in this way, a reduction in the size of the trigger box is achieved. Specific Example 1-2 In the specific example 1-2, the AP 100 trigger box generator 104 sets a plurality of modified user information using a trigger box. More specifically, as in the example shown in Figure 11, the trigger box generator 104 generates a trigger box, such that two modified user information fields are included in a trigger box. As in specific example 1-1, the trigger box generator 104 generates a trigger box, such that two modified user information fields are included in a trigger box. As in specific example 1-1, the trigger box generator 104 sets AID=0, which is one of the unused AIDs, in the AID 12 subfield of each modified user information field, thereby informing terminal 200 that each user information field that includes this AID 12 subfield is modified user information. In Figure 11, the AP 100 specifies seven contiguous RA-RUs nnzrnn / cznz / E / YiAi in the first modified user information and specifies MCS#1 (for example, 16QAM) for these RUs. Additionally, the AP 100 specifies one RA-RU in a second modified user information and specifies MCS#2 (for example, QPSK) for this RU. In a case where there is overlap in the RA-RU between multiple modified user information, as in the example shown in Figure 11 (where a RU is overlapping in the center of seven RA-RUs), the RA 206 resource determination unit of terminal 200 prioritizes the modified user information, from among the multiple modified user information, that specifies a smaller number of contiguous RUs. That is, in Figure 11, priority is given to the modified user information that specifies a RA-RU (contiguous RUs = 1) in the SS distribution, and thus MCS #2 is used for the central RU. This allows the use of multiple different parameters for multiple RA-RUs specified by a trigger box. Furthermore, by setting or adjusting the number of contiguous RUs specified by the modified user information to 1, it is possible to specify a parameter individually for each RU. For example, in Figure 11, for the central RU of seven different RA-RUs, a different parameter (MCS) is set than those (nnzrnn / cznz / E / YiAi) for the other RUs. That is, in Figure 11, of seven contiguous RA-RUs, the same parameter (MCS) is set for six RUs that form different discontinuous bands from the central RU. For example, when adjusting or setting a plurality of modified user information in an actuator box, the AP 100 may set a robust MCS (e.g., QPSK) in one RU (e.g., a RU located near DC) of a plurality of contiguous RA-RUs such as those shown in Figure 11. In the specific example 1-2, as described above, it is possible to specify a parameter (MCS, target RSSI, or similar) individually, for each RA for the RA in a mode similar to the mode using normal user information except that the spatial multiplexing is limited to the spatial multiplexing level = 1 (no MIMO) for all RA-RUs. Thus, according to the specific example 1-2, even in the case where modified user information is used, it is possible to specify a parameter, individually, for each RU, which makes it possible to use a parameter depending on the expected performance for each RU and in this way, an increase in performance can be achieved. nnzrnn / cznz / E / YiAi Furthermore, in the specific example 1-2, when defining a rule regarding the priority applied when there is an overlap between the RUs specified by a plurality of modified user information, the AP 100 is able to specify a parameter depending on the expected performance of the RU by means of a trigger box with a small size (with a small number of user information fields). It is observed that a method of distributing RA-RUs by means of a plurality of modified user information included in an activator box is not limited to the one shown in the example in Figure 11. For example, as shown in Figure 12, the AP 100 could specify the RUs using two modified user information pieces included in a trigger box, ensuring no overlap between the two pieces of modified user information. In Figure 12, the AP 100 specifies four RA-RUs using the first modified user information piece and specifies MCS #1 (e.g., 16QAM) for these RUs. The AP 100 then specifies, using a second modified user information piece, three RA-RUs in an area adjacent to the four RA-RUs specified by the first modified user information piece (i.e., ensuring no overlap in the area) and specifies MCS #2 (e.g., QPSK) for these RUs. As shown in Figure 13, the AP 100 could specify the RUs using two modified user information pieces included in an activator box, such that the RUs specified by the respective modified user information pieces are located in separate areas. In Figure 13, the AP 100 specifies four RA-RUs using the first modified user information piece and three RA-RUs using the second modified user information piece, such that the three RA-RUs are in the separate area from the four RUs for the RA specified by the first modified user information piece (and thus, there is no overlap). Although in Figure 13, MCS #1 is applied to the RUs specified by any modified user information, a different parameter could be specified individually for each modified user information. That is, an identical or similar parameter in terms of MCS could be set for a plurality of modified user information, or a different parameter could be set individually for each modified user information, as in Figure 12. Furthermore, as shown in Figure 13, an arbitrary RU, such as a planned access RU or an unspecified RU (non-distributed RU), could exist between the two areas specified by the two respective modified user information.It is observed that in a case where the parameters in terms of encoding type, MCS, and DCM are established in common for all RUs specified by multiple user information, there is a reduction in the degree of flexibility, making the adjustment dependent on a transmission characteristic, or similar, of each RU. However, in OFDMA base random access, when a terminal obtains the right to transmit, a RU is randomly selected from all RA-RU random accesses. Therefore, there is a difference in the amount of data that can be transmitted by a RU among the RUs specified by multiple modified user information. It is necessary to determine the amount of data in a transmission frame once the terminal selects a RU, which increases the complexity of the transmission frame generation process.However, in the case where a common parameter is used for a plurality of modified user information, the amount of data that can be transmitted is the same for all random access RA-RUs, which allows simplification in the transmission frame generation process carried out in a terminal. In the examples described above with reference to Figures 11-13, it is assumed, for illustrative purposes, that two modified user data fields are included in a trigger box. However, two or more modified user data fields could be included in a trigger box. Specific Example 2 In specific example 2, a plurality of AIDs were used to specify the RA-RU. That is, the AID 103, 205 controller determines a plurality of AIDs used to specify user information (modified user information or normal user information) that indicates the RA-RU. The AID 103, 205 controller determines the user information that specifies the RA-RU while distinguishing between an unused AID that corresponds to normal user information and an unused AID that corresponds to modified user information. For example, the AID 103, 205 controller determines AID = 0 as an unused AID for specifying normal user information and AID = 2048 as an unused AID for identifying modified user information. That is, trigger box generator 104 sets AID = 0 in subfield AID 12, thereby informing terminal 200 that the user information field containing subfield AID 12 is in normal user information format and specifies one RA-RU. Furthermore, trigger box generator 104 sets AID = 2048 (an unused AID other than AID = 0) in subfield AID 12, thereby informing terminal 200 that the user information field containing subfield AID 12 is in modified user information format and specifies a plurality of RA-RUs (the contiguous RA-RUs). The AID = 2048 corresponds to a value set in the 12-bit AID 12 subfield, such that only the MSB (most significant bit) is 1 and all 11 lower-order bits are 0. Thus, in a case where the AID is abused or set to either 0 or 2048 as previously described, Terminal 200 determines that user information for RA is specified when all 11 lower-order bits are equal to 0. In other words, it is possible to determine whether modified user information or normal user information is specified solely by the MSB, thereby simplifying the process performed by Terminal 200. In the example shown in Figure 14, the AP 100 trigger box generator 104 sets a plurality of unused AIDs (AID = 0, 2048), such that AID = 0 is set in the AID 12 subfield of a normal user piece of information, and AID = 2048 is set in the AID 12 subfield of each modified user piece of information. Additionally, in Figure 14, the AP 100 specifies three RA-RUs (the contiguous RUs = 3) for each of the two modified user pieces of information and specifies MCS #1 (for example, 16QAM) for each of these RUs. The AP 100 also specifies one RA-RU for a normal user piece of information and specifies MCS #2 (for example, QPSK) for this RU. This makes it possible to use multiple different parameters, in different ways, for multiple RA-RUs specified in a trigger box. It is also possible to specify a parameter individually for each RU by adjusting the setting so that the number of contiguous RUs = 1, as specified by the modified user information, or a parameter is specified individually for each RU when using normal user information. For example, in Figure 14, a central RU in seven contiguous RA-RUs is set with a different parameter (MCS) than the parameters set in the other RUs. That is, in Figure 14, of the seven contiguous RA-RUs, six different RUs from a central RU form a dashed band, and the same parameter (MCS) is set for these seven RUs. For example, the AP 100 is able to adjust a robust elastic high-error MCS, individually, for a portion of the RUs (e.g., a central RU) intended to find the degradation in performance when using normal user information or modified user information in which the number of contiguous RUs is set to 1. According to Specific Example 2, as previously described by nnzrnn / cznz / E / YiAi, it is possible to apply a parameter based on the expected throughput for each RU by combining standard user information and modified user information, thereby increasing throughput. Furthermore, according to Specific Example 2, the AP 100 can also specify contiguous RA-RUs using modified user information, as in Specific Example 1, thereby reducing the trigger box size. Additionally, in Specific Example 2, it is also possible to set the number of spatially multiplexed flows in the SS distribution subfield (i.e., MIMO can be used) using standard user information. As shown in Figure 14, for example, AID = 0 is set in the normal user information and AID = 2048 is set in the modified user information. However, the values ​​of unused AIDs set in the normal user information and in the modified user information are not limited to 0 and 2048, and other values ​​could be set. Furthermore, in specific example 2, the RA-RUs specified in an activator box do not necessarily need to be contiguous in the example shown in Figure 14, but rather the RUs located in discontinuous areas separated from each other could be specified, for example, as in the example shown in Figure 15. A specific example 2-1 and a specific example 2-2, nnzrnn / cznz / E / YiAi which are also detailed examples of specific example 2, of the description methods, using an unused ID, is so that the user information field is either the normal user information or the modified user information described below. Specific Example 2-1 In the specific example 2-1, the AP 100 trigger frame generator 104 informs terminal 200 of the RA-RU specified by normal user information (AID = 0) and the contiguous RA-RUs specified by modified user information (an unused AID with an AID value of Ψ 0). More specifically, as in the example shown in Figure 16, trigger frame generator 104 specifies seven RA-RUs (contiguous RUs = 7) that use modified user information (AID = 2048) and specifies MCS #1 (e.g., 16QAM) for these RUs. Additionally, trigger frame generator 104 specifies one RA-RU that uses normal user information (AID = 0) and specifies MCS #2 (e.g., QPSK) for this RU. In a case where there is an overlap between an RA-RU specified by normal user information and adjacent RA-RUs specified by modified user information, as shown in Figure 16 (in Figure 16, this occurs in the central RU across seven RA-RUs), the resource determination unit RA 206 of terminal 200 prioritizes the normal user information specifying the RU. That is, in Figure 16, with respect to the central RU, priority is given to the normal user information, and thus MCS #2 is applied to the central RU. Thus, in specific example 2-1, as in specific example 2 (Figure 14), it is possible to use a plurality of parameters, in different ways, for the RA-RUs specified in an activator box. For example, as shown in Figure 16, the AP 100 could individually establish a robust, high-error elasticity MCS for a portion of the RUs (e.g., a central RU) intended to detect performance degradation when using standard user input. In specific example 2-1, when defining a rule that indicates which RU is given priority in a case where there is an overlap between an RU specified by normal user information and an RU specified by modified user information, the AP 100 is able to specify a parameter depending on the expected performance of the RU using a trigger box of a small size (with a small number of user information fields). For example, in specific example 2-1 (Figure 16), it is possible to make a similar adjustment of the RA-RUs to the adjustment in specific example 2 (Figure 14) by using a trigger box of a smaller size (with a smaller number of user information fields). Specific Example 2-2 In the specific example 2-2, each of the plurality of unused AIDs is associated with a restriction condition (a terminal restriction condition) imposed on terminal 200, which transmits an RA signal. That is, AP 100 specifies, using a plurality of unused AIDs, a terminal restriction condition imposed on terminal 200, which transmits an RA signal. As in the example shown in Figure 17, the AID 103, 205 controller determines AID = 2008 and AID = 2009 as the unused AIDs that correspond to the modified user information specified by the RA-RU. Furthermore, the AID 103, 205 controller assigns different terminal restriction conditions to AID = 2008 and AID = 2009, respectively. The AP 100 trigger box generator 104 sets AID = 2008 or 2009 in the AID 12 subfields, thereby informing terminal 200 that both of the user information fields that include the AID 12 subfield are in the modified user information format. In Figure 17, AP 100 specifies the connection conditions for terminal 200, since the different terminal restriction conditions between the respective unused AIDs specify modified user information. More specifically, as shown in Figure 17, an nnzrnn / cznz / E / YiAi A RA-RU specified by AID = 2008 is a limited RA-RU for use between AP 100 and terminal 200 (associated STA) connected to AP 100. A RA-RU specified by AID = 2009 is a limited RA-RU for use between AP 100 and a non-connected terminal 200 (non-associated STA). In this way, it is possible to classify the 200 terminals that transmit an RA signal using each RU in the associated STAs and the non-associated STAs. Therefore, the AP 100 establishes an appropriate parameter, individually, for each connection condition of a 200 terminal. For example, AP 100 already has information about an associated STA (in terms of a communication condition of terminal 200), and thus, AP 100 is able to appropriately adjust an uplink parameter (power, MCS, or similar) for the associated STA. In contrast, AP 100 has no information about the non-associated STA, and thus, AP 100 establishes a robust, high-error elasticity value as an uplink parameter for the non-associated STA. In this way, as shown in Figure 17, AP 100 establishes the RA-RU separately for the associated and non-associated STAs and performs planning so that OFDMA multiplexing does not occur within the same packet. This makes it possible to achieve, for example, a reduction in interference between terminals 200 for which different nnzrnn / cznz / E / YiAi parameters are established (e.g., transmit power).Furthermore, the AP 100 could establish the MCS with a high error elasticity with an unassociated STA, thereby avoiding performance degradation. In an alternative example, AP 100 could specify a transmit power condition for a 200 terminal as a terminal restriction condition that is different for each unused AID indicating modified user information (not illustrated in the figures). More specifically, an RA-RU specified by AID = 2008 is a RA-RU limited to use by a 200 terminal that has a minimum available power equal to or less than its required uplink transmit power; that is, it is capable of transmitting at the required uplink transmit power. An RA-RU specified by AID = 2009 is an RA-RU limited to use by a 200 terminal that has a minimum available power greater than its required uplink transmit power; that is, it is not capable of transmitting at the required uplink transmit power. In this way, AP 100 could perform scheduling so that OFDMA multiplexing is not performed in the same packet for a 200 terminal that is not capable of transmitting with the required uplink power and a 200 terminal that is capable of transmitting with the required uplink power, thus reducing interference between the 200 terminals. AP 100 could establish an MCS with greater error elasticity for a 200 terminal that is not capable of transmitting with the required uplink power, thus preventing performance degradation. In an alternative example, such as a different terminal restriction condition for each unused AID that specifies modified user information, AP 100 could specify a transmit data restriction condition (not illustrated) imposed on a 200 terminal. More specifically, AID = 2008 could specify modified user information that includes trigger-dependent user information in a user information field, while AID = 2009 could specify modified user information that does not include trigger-dependent user information in a user information field. In a case where a user information field includes trigger-dependent user information (i.e., where an AMPDU (Aggregate MAC Protocol Data Unit), which is a combination of multiple MPDUs, is used), the processing time of a process performed by AP 100 is expected to be longer than in a case where trigger-dependent user information is not present. Therefore, for example, AP 100 could perform scheduling so that a RU used by terminal 200 is selected based on the processing time for an uplink signal transmitted in response to an instruction in a trigger frame, thereby increasing RU usage efficiency. It is observed that the terminal restriction conditions are not limited to the terminal 200 connection condition, the transmission power condition, and the transmission data restriction condition described above. According to the specific example 2-2, as described above, by providing an instruction in which a plurality of used AIDs are associated with the restriction conditions imposed on terminal 200, AP 100 is able to properly perform RA-RU planning depending on the state of terminal 200. It is observed that in the specific example 2-2, the RA-RUs specified by an activator box are not limited to contiguous RUs such as those shown in Figure 17. For example, RUs located in discontinuous areas separated from each other could be specified as shown nnzrnn / cznz / E / YiAi in Figure 18. Specific examples 1 and 2 of the methods for describing a user information field format that uses an unused AID have been described previously. In the examples described above, the parameter specified by the modified user information, by way of example, is the MCS. However, other parameters (encoding type, DCM, target RSSI) could also be specified in a similar way to the MCS. Advantageous Effects According to the current mode, as previously described, the AP 100's 104 trigger box generator establishes an unused AID, which will not be used for planned access, in modified user information that specifies one or more contiguous resource units for random access in a trigger box. This enables a 200 terminal to determine, based on an AID value indicated in an AID 12 subfield of each user information field in the trigger box, whether or not the user information field is modified user information. According to this modality, it is therefore not necessary to use (consume) a reserved area of ​​an trigger type to specify modified user information. That is, it is possible to specify modified user information while leaving room for a future extension of the standard. In this way, according to this modality, it is possible to properly set modified user information in a trigger box. Furthermore, according to this method, by establishing multiple modified user information (or one standard user information and at least one modified user information) in an activation box, it is possible to distribute not only contiguous user information but also non-contiguous user information, and it is also possible to specify different parameters for the respective user information. This makes it possible to specify a parameter depending on the expected performance for each of the multiple RA-RUs specified by an activation box, thereby achieving a performance increase. Second Modality For example, in a case where modified user information is set as described above with reference to Figure 6A or other figures, the reduction of the trigger box size by suppressing the trigger-dependent common information subfield and the trigger-dependent user information subfield is under discussion. However, in a case where the trigger type is nnzrnn / cznz / E / YiAi the basic trigger (see Figure 3) (in a case where the trigger box instructs normal data transmission without imposing any restrictions on the uplink signal format), it is useful not only in planned access but also in RA transmission for a user information field to include a trigger-dependent user information subfield, thereby providing notification of receive information (a restriction on the number of combined MPDUs, a recommended AC, or the like) in the uplink transmission data shown in Figure 5. In view of the above, a second modality provides an efficient method of transmitting restriction information in uplink transmission data when modified user information is transmitted. According to the present modality, a wireless communication system includes an AP 300 (radio transmitting apparatus) and a terminal 400 (radio receiving apparatus). The AP 300 transmits a trigger frame that specifies an RA transmission to the terminal 400. The terminal 400 receives the trigger frame and transmits the RA to the AP 300 using a resource specified in the trigger frame. AP Configuration Figure 19 shows a block diagram illustrating a configuration of the AP 300 according to the present nnzrnn / cznz / E / YiAi mode. In Figure 19, similar blocks that operate in a mode similar to the blocks according to the first mode (Figure 8) are denoted by similar reference symbols, and their descriptions are omitted. More specifically, the AP 300 differs from the AP 100 (Figure 8) according to the first mode because the trigger-dependent information controller 301 is also provided, and the trigger frame generator 302 operates in a similar mode. The trigger-dependent information controller 301 determines the trigger-dependent information (either common trigger-dependent information or trigger-dependent user information) depending on the trigger type and outputs the trigger-dependent information (the restriction information in the uplink transmission data) and information indicating a field and subfield in which the trigger-dependent information is located in the trigger frame generator 302. The location of the trigger-dependent information within the trigger box is defined, for example, by descriptions or similar elements, and this location is recognized equally by the transmitting and receiving devices (the AP 300 and the terminal 400). For example, in a case where the trigger type is Basic Trigger and the user information field format is Modified User Information nnzrnn / cznz / E / YiAi, the restriction information in the uplink transmission data is included as trigger-dependent information within a trigger box. A method for applying trigger-dependent information to the terminal 400 will be described later. The trigger box generator 302 performs, in addition to the operation performed by the trigger box generator 104 according to the first mode, an operation of adjusting the trigger-dependent information in a predefined field and a subfield of the trigger box according to an instruction given by the trigger-dependent information controller 301. Terminal Configuration Figure 20 shows a block diagram illustrating a configuration of terminal 400 according to the present modality. In Figure 20, similar blocks operating in a mode similar to the blocks according to Figure 9 are denoted by similar reference symbols, and their descriptions are omitted. More specifically, terminal 400 differs from terminal 200 (Figure 9) according to the first modality because the activator-dependent information acquisition unit 401 is also provided, and the RA generator 402 operates in a different mode. The activator-dependent information acquisition unit nnzrnn / cznz / E / YiAi 401 acquires activator-dependent information (either activator-dependent common information or activator-dependent user information) from the activator box output from the activator box decoder 204 and outputs the acquired activator-dependent information to the RA generator 402. Based on the RA-RU and control information to generate the RA signal determined by the RA resource determination unit 206 and the trigger-dependent information output of the trigger-dependent information acquisition unit 401, the RA generator 402 generates an RA signal that includes a terminal ID and the transmission information (data, control information, or the like) associated with terminal 400. AP 300 and Terminal 400 Operations The operations of AP 300 and Terminal 400 are described below in accordance with this procedure. In a case where the trigger type is the basic trigger, the AP 300 specifies the restriction information in the uplink transmission data as trigger-dependent information even when the format of the user information field is modified user information. Specific examples 1-3 of methods for describing receive information in uplink nnzrnn / cznz / E / YiAi transmission data in a trigger box that includes modified user information are described below. Specific Example 1 As illustrated in Figure 6A, in an activator box where the modified user information does not include a user-dependent user information subfield, when the activator type is the basic activator, in order for the terminal 400 to detect the size of each user information field in the activator box (in order to detect the boundary between each user information field), it is necessary to decode the AID 12 subfield of each user information field, which results in an increase in the complexity of the receiving process performed by the terminal 400. In view of the above, in specific example 1, in a case where the trigger type is the basic trigger, the modified user information is configured so that the trigger-dependent user information subfield is also included in the modified user information and the restriction information in the uplink data is set as the trigger-dependent information. That is, in a case where the type of activator box is the basic activator, the AP 300's 302 activator box generator sets the nnzrnn / cznz / E / YiAi restriction information on the uplink signal in the transmission in the modified user information. More specifically, in the example shown in Figure 21, an activator box includes a mixture of normal user information (AID = 1 and 2) that specifies the RUs for planned access and modified user information (AID = 0) that specifies a plurality of RA-RUs. Furthermore, in Figure 21, the basic activator is specified in a activator type subfield of a common information field. In this case, for each normal user information, the restriction information on the uplink transmission data specific to each terminal is set as the trigger-dependent user information. On the other hand, for each modified user information, only in the case where the basic trigger is set as the trigger type, is the restriction information on the uplink transmission data that will be applied to an RA-RU set as the trigger-dependent user information. Thus, in a case where the trigger type included in the common information of the trigger box is the basic trigger, it is possible to determine that all user information fields have sizes (for example, 5 bytes) that include the user information dependent on the trigger (i.e., they have the same size). In other words, Terminal 400 does not need to decode an AID 12 subfield of each user information field to detect the size of the user information field. According to specific example 1, as described above, the size of the user information field is determined only from the type of trigger without considering the format of the user information field, and in this way, the simplification of the reception process carried out by terminal 400 is achieved. Furthermore, the AP 300 can report trigger-dependent user information even when the user information has been modified. Similarly, in RA transmission via the 400 terminal, data transmission restriction information can be used effectively, as in planned access transmission. Specific Example 2 In specific example 2, in a case where the activator type of the activator box is the basic activator, the restriction on uplink signal transmission is imposed on terminal 400 which is instructed to use one or more contiguous RA-RUs specified by the modified user information in the activator box. That is, in specific example 2, as in the example shown in Figure 22, in a case where the type of nnzrnn / cznz / E / YiAi activator is the basic activator, unlike specific example 1 (Figure 21), any modified user information does not include an activator-dependent user information subfield. Regarding a fixed restriction imposed on the uplink data transmitted by terminal 400, for example, an MPDU separation factor (MU) and an aggregation limit (TID) could be limited to fixed values ​​(a single MPDU of small size) assuming the number of MPDUs = 1. This makes it possible to prevent AP 300 from experiencing a response time delay. Note that the fixed restriction on the uplink data transmitted by terminal 400 is not limited to the fixed value assuming the number of MPDUs = 1, although other values ​​could be used. Thus, in the specific example 2, when the trigger type is the basic trigger, by specifying a plurality of RA-RUs that use modified user information as in the first mode, it is possible to apply the restriction on RA transmission using the RA-RUs specified by the modified user information while reducing the trigger frame size. Specific Example 3 In specific example 3, in the case where the trigger type is the basic trigger, as shown in Figure 23, the common information includes a subfield of trigger-dependent user information and the restriction information on data transmission is set by a parameter that is common to all OFDM 400 multiplexed terminals. That is, in a case where the type of activator box is the basic activator, the AP 300's 302 activator box generator sets the restriction information on the uplink signal transmission in the common information. In other words, in specific example 3, in the user information field, the restriction information on the uplink signal in the transmission is not established without considering the format of the user information field (modified user information or normal user information). Therefore, as shown in Figure 23, even in the case where the trigger type is the basic trigger, the trigger-dependent user information subfield is not included in the modified user information or the normal user information. Establishing the restriction information in the common information causes the restriction condition in data transmission to be the same for all terminals multiplexed by OFDM 400. However, the user information does not include the trigger-dependent user information subfield, and in this way, the reduction in the size of the trigger box is achieved. In specific example 3, without considering the format of the user information field, the user information does not include the trigger-dependent user information subfield, and thus the size of all user information fields is determined solely by the trigger type, as in specific example 1. Therefore, it is unnecessary for terminal 400 to decode the AID 12 subfield of each user information field to detect the size of the user information field, thereby simplifying the reception process performed by terminal 400. Specific examples 1-3 of methods for describing restriction information in uplink transmission data in an activator box that includes modified user information have been described previously. In Figures 21-23, the RA-RUs specified by an activator box are, by way of example, contiguous RUs. However, RA-RUs are not limited to contiguous RUs. RUs located in discontinuous areas separated from each other (not shown) could be specified by an activator box as in the first modality (e.g., Figures 13, 15, and 18). nnzrnn / cznz / E / YiAi Furthermore, the operations described above in accordance with this modality are not limited to the case where the trigger type is the basic trigger. For example, when the trigger type allows AR transmission and the trigger type includes trigger-dependent user information, the operations in accordance with this modality are possible in a similar way as described above and similar effects can be achieved. The modalities of the present description have been described previously. Other Modalities (1) As shown in Figure 24, an activator box could include a mix specifying an RA-RU that uses modified user information or normal user information as described above with reference to modalities and that specifies a planned access RU. (2) In the modes described above, the methods for specifying modified user information using an unused AID have been explained. Instead of an unused AID, modified user information could be specified using a reserved area (1 bit) in a user information field. For example, a bit in the reserved area could be used to specify the format of the user information field, indicating whether the format is modified user information or normal user information. Alternatively, modified user information could be specified using another subfield in the user information field. For example, AID = 0 could specify an RA-RU, and without disabling the DCM in the RA-RU, a DCM bit could be used to specify the format, indicating whether the format is modified user information or normal user information. (3) In the description of an RA-RU, a predetermination could be made regarding the order, in the trigger box, of the notification of normal user information (specified by AID = 0) and modified user information (specified by an unused AID with an AID value of 0). This makes it possible to simplify the reception process performed by the terminal. In the descriptions, to simplify the reception process at the terminal, the notification order is defined so that, after user information is entered in the activation box, a notification of the planned access RU is given, and then a notification of an RA-RU is given. In cases where RA-RU notifications are given by a mixture of normal user information and modified user information, as in the present mode, predetermining the notification order of this user information makes it possible to simplify the reception process at the terminal. nnzrnn / cznz / E / YiAi For example, as shown in Figure 25, the notification order could be predetermined, so that the notification is given in the notification order of a planned access RU (in the example shown in Figure 25, the user information specifies the individual terminals with AID = 1, 2), the notification of an RA-RU that uses modified user information (in the example shown in Figure 25, specified by AID = 2048) and the notification of an RA-RU that uses normal user information (in the example shown in Figure 25, specified by AID = 0).By predetermining the notification order as described above, when there is an overlap between the specified RA-RUs as in the modalities described above (for example, see Figure 16), the reception process at the terminal can be simplified, for example, by overwriting the instruction in the modified user information with the normal user information. Furthermore, the notification order for multiple modified user information pieces included in an activator box could be predetermined, so that notifications are given in descending order of the number of contiguous RUs specified by the modified user information. By predetermining the notification order as described above, when there is an overlap between the RA-RUs specified as the modes described above (e.g., see Figure 11), the receiving process at the terminal can be simplified, for example, by overwriting modified user information that specifies a large number of contiguous RUs with modified user information that specifies a small number of contiguous RUs. (4) The present description could be implemented using software, hardware, or software in conjunction with hardware. Each functional block described in the modalities could be implemented, partially or completely, by an LSI, which is an integrated circuit. Each process described in the modalities could be controlled, partially or completely, by an LSI or a combination of LSIs. An LSI could be implemented using a chip. A chip could include some or all of the functional blocks. Each LSI could include data input and output. The LSI could also be called an IC, a system LSI, a super LSI, or an ultra LSI, depending on the integration density. The integrated circuit implementation method is not limited to LSIs; the integrated circuit could be implemented as a dedicated circuit or a general-purpose processor.The integrated circuit could also be implemented using an FPGA (Field-Programmable Gate Array) that can be programmed once the LSI is manufactured or reconfigured—a reconfigurable processor that allows for the connection or adjustment of circuit cells within the LSI. The present description could be implemented using either digital or analog processing. If a new integration circuit technique, different from LSI techniques, is developed in the future through advances in semiconductor or related technologies, the functional blocks could be implemented using this new technique. The use of biotechnology is also potentially possible. A communication apparatus according to the present description includes an activator signal generator that generates an activator signal that instructs an uplink signal transmission, wherein in a case where the activator signal includes a first terminal information field that specifies one or more contiguous resource units for random access, an unused ID that will not be used as a terminal ID is placed in the terminal ID subfield in the first terminal information field, and a transmitter that transmits the generated activator signal. In the communication apparatus according to the present description, when the resource unit for random access is specified, an unused ID value is set in the terminal ID subfield. In the communication apparatus according to the present description nnzrnn / cznz / E / YiAi, in a case where an activating signal includes a plurality of first terminal information fields, when there is an overlap in one or more contiguous resource units for random access specified, respectively, by means of the first terminal information fields, the priority of a plurality of first terminal information fields for the overlapping resource units is determined, so that priority is given to an instruction described in a first terminal information field that specifies a smaller number of resource units. In the communication apparatus according to the present description, when the resource unit for random access is specified, there is a plurality of unused ID values ​​that can be set in a terminal ID subfield. In the communication apparatus described herein, the activating signal generator establishes a first unused ID value, from a plurality of unused ID values, in a terminal ID subfield in a first terminal information field, and establishes a second unused ID value in a terminal ID subfield in a second terminal information field that specifies the resource unit for random access. In the event of an overlap between the resource unit specified by the first terminal information field and the resource unit specified by the second terminal information field, the priority of the overlapping resource units is determined so that priority is given to an instruction specified in the second terminal information field. In the communication apparatus according to the present description, each of the unused ID values ​​is associated with a restriction condition imposed on a terminal that transmits a random access signal. In the communication apparatus according to the present description, in a case where an activating signal is of the type that does not impose a restriction on the format of an uplink signal, the activating signal generator sets the information in the first terminal information field to specify a restriction on an uplink signal in the transmission. In the communication apparatus according to the present description, in a case where an activating signal is of a type that does not impose a restriction on the format of an uplink signal, the restriction on an uplink signal in transmission is applied to a terminal instructed to use one or more contiguous resource units for the random access specified by the first terminal information field of the activating signal. nnzrnn / cznz / E / YiAi In the communication apparatus according to the present description, in a case where an activating signal is of a type that does not impose a restriction on the format of an uplink signal, the activating signal generator sets the information indicating a restriction on an uplink signal in the transmission not in the first terminal information field but in a common information field that includes information common to the terminals. The communication method according to this description includes generating an activator signal that instructs an uplink signal transmission. In a case where the activator signal includes a first terminal information field that specifies one or more contiguous resource units for random access, an unused ID is set in a terminal ID subfield within the first terminal information field, and the generated activator signal is transmitted. Industrial Applicability One aspect of this description is useful for effectively using redundant fields or for reducing redundant fields. List of Reference Numbers 100, 300 AP nnzrnn / cznz / E / YiAi 101 RA resource controller 102 user information controller 103, 205 AID controller 104, 302 activator box generator 105, 208 transmission signal modulator 106, 202 radio transmitter / receiver 107, 201 antenna 108, 203 receive signal demodulator 109 quality estimator 200, 400 terminal 204 trigger frame decoder 206 RA resource determination unit 207, 402 RA generator 301 trigger-dependent information controller 401 Activator-dependent information acquisition unit. It is hereby stated that, as of this date, the best method known to the applicant for putting the aforementioned invention into practice is the one that is clear from the present description of the invention.

Claims

1. A communication apparatus, characterized in that it comprises: a receiver that, in operation, receives an activator panel comprising a first user information field, a second user information field, and a third user information field, the first user information field comprising a first terminal ID subfield and a first resource unit (RU) distribution subfield, the second user information field comprising a second terminal ID subfield and a second RU distribution subfield, and the third user information field comprising a third terminal ID subfield and a third RU distribution subfield, wherein a first value other than a value used for a terminal ID is set to the first terminal ID subfield for random access from a station associated with an access point,the first RU distribution subfield indicates a first starting RU of one or more contiguous first random access RUs (RA-RUs), and the first user information field further comprises a first RA-RU subfield number indicating a first number of RUs in the one or more contiguous first RA-RUs, a second value other than a value used for a terminal ID is set to the second terminal ID subfield for random access of a station not associated with the access point, the second RU distribution subfield indicates a second starting RU of one or more contiguous second RARUs, and the second user information field further comprises a second RA-RU subfield number indicating a second number of RUs in the one or more contiguous second RARUs, and a third value used for a terminal ID is set to the third terminal ID subfield for planned access of a station associated with the access point,and all user information fields for planned access, including the third user information field, precede all user information fields for random access, including the first and second user information fields in the trigger box; and a transmitter, wherein, in a first instance where the communication apparatus is associated with the access point, the transmitter transmits an uplink signal using at least one of the first one or more contiguous RA-RUs nnzrnn / cznz / E / YiAi, and, in a second instance where the communication apparatus is not associated with the access point, the transmitter transmits an uplink signal using at least one of the second one or more contiguous RA-RUs.

2. The communication apparatus according to claim 1, characterized in that the first one or more contiguous RA-RUs distributed across the first user information field do not overlap with the second one or more contiguous RA-RUs distributed across the second user information field.

3. The communication apparatus according to claim 1, characterized in that a coding type and a modulation and coding scheme (MCS) are configured separately for the first one or more contiguous RA-RUs distributed across the first user information field and the second one or more contiguous RA-RUs distributed across the second user information field.

4. A communication method implemented by a communication apparatus, the communication method being characterized in that it comprises: receiving an activator frame comprising a first user information field, a second user information field, and a third user information field, the first user information field comprising a first terminal ID subfield and a first resource unit (RU) distribution subfield, the second user information field comprising a second terminal ID subfield and a second RU distribution subfield, and the third user information field comprising a third terminal ID subfield and a third RU distribution subfield, wherein a first value other than a value used for a terminal ID is set to the first terminal ID subfield for random access from a station associated with an access point,the first RU distribution subfield indicates a first starting RU of one or more contiguous first random access RUs (RA-RUs), and the first user information field further comprises a first RA-RU subfield number indicating a first number of RUs in the one or more contiguous first RA-RUs, a second value other than a value used for a terminal ID is set to the second Terminal ID subfield for random access of a station not associated with the access point, the second RU distribution subfield indicates a second starting RU of one or more contiguous second RA-RUs, and the second user information field further comprises a second RA-RU subfield number that indicates a second number of RUs in the one or more contiguous second RA-RUs, and a third value used for a terminal ID is set to the third Terminal ID subfield for planned access of a station associated with the access point,and all user information fields for planned access, including the third user information field, precede all user information fields for random access, including the first and second user information fields in the trigger box; in the first case where the communication apparatus is associated with the access point, transmit an uplink signal using at least one of the first one or more contiguous RA-RUs; and in the second case where the communication apparatus is not associated with the access point, transmit an uplink signal using at least one of the second one or more contiguous RA-RUs.

5. The communication method according to claim 4, characterized in that the first one or more contiguous RA-RUs distributed across the first user information field do not overlap with the second one or more contiguous RA-RUs distributed across the second user information field.

6. The communication method according to claim 4, characterized in that a coding type and a modulation and coding scheme (MCS) are configured separately for the first one or more contiguous RA-RUs distributed across the first user information field and the second one or more contiguous RA-RUs distributed across the second user information field.

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