Communication device, communication method, and integrated circuit

Abstract

To provide a communication device and a communication method, for allocating a persistent .SOLUTION: A communication device comprises: a circuit which is a circuit that, in operation, generates a transmission signal containing a common field, a user specific field, and a data field, and in which the common field contains RU information on one or more allocations in the data field, the user specific field contain one or more user information, each indicating a user specific allocation among one or more allocations in the data field; and a transmission device that, in operation, transmits the generated transmission signal. Therein, the user specific field is free from at least one user information piece for a persistent allocation containing a recurring transmission among the one or more allocations.SELECTED DRAWING: Figure 3B

Description

[Technical Field]

[0001] The present disclosure relates to a communication apparatus and method for Persistent Allocation (PA), also known as permanent allocation, continuous allocation, or static allocation, and more particularly to a communication apparatus and method for PA in an Extremely High Throughput Wireless Local Area Network (EHT WLAN). [Background technology]

[0002] In the standardization of next-generation wireless local area networks (WLANs), a new radio access technology that is backward compatible with IEEE 802.11a / b / g / n / ac / ax technologies has been discussed in the IEEE 802.11 Working Group and named Extremely High Throughput (EHT) WLAN.

[0003] For EHT WLANs, it is desirable to increase the maximum channel bandwidth from 160 MHz to 320 MHz, increase the maximum number of spatial streams from 8 to 16, and support multi-band operation to provide significant peak throughput and capacity increases over 802.11ax High Efficiency (HE) WLANs.

[0004] However, there has been no discussion of communication devices and methods for persistent assignment (PA) in the context of EHT WLANs.

[0005] Therefore, what is needed is a communication apparatus and method that provides a feasible technical solution for PA in the context of EHT WLAN. Furthermore, other desirable features and characteristics will become apparent from the following detailed description and appended claims, taken in conjunction with the accompanying drawings and the background of this disclosure. Summary of the Invention

[0006] Non-limiting and exemplary embodiments facilitate providing a communications apparatus and method for persistent allocation in the context of an EHT WLAN.

[0007] According to an embodiment of the present disclosure, there is provided a communications device comprising: a circuit that, during operation, generates first transmission signals including user information of a plurality of users for downlink MU-MIMO assignments, each of the first transmission signals indicating a user-specific assignment; and further generates second transmission signals including a common field, a user-specific field, and a data field, wherein the data field includes a transmission of the downlink MU-MIMO assignment; and a transmitter that, during operation, transmits the first transmission signals and the second transmission signals; and determines whether the user-specific assignments of the downlink MU-MIMO assignments are persistent or not.

[0008] According to another embodiment of the present disclosure, there is provided a communication method, the method including: generating first transmission signals including user information of multiple users for downlink MU-MIMO assignments, each of the first transmission signals indicating a user-specific assignment; generating second transmission signals including a common field, a user-specific field, and a data field, where the data field includes a transmission of the downlink MU-MIMO assignment; and transmitting the first transmission signal and the second transmission signal, wherein it is determined that the user-specific assignments of the downlink MU-MIMO assignments are persistent or not.

[0009] It should be noted that the general or specific embodiments may be realized as a system, a method, an integrated circuit, a computer program, a storage medium, or any combination thereof.

[0010] Additional benefits and advantages of the disclosed embodiments will become apparent from the specification and drawings. Benefits and / or advantages may be obtained individually by various embodiments and features of the specification and drawings, not all of which are provided to obtain one or more of such benefits and / or advantages. [Brief explanation of the drawings]

[0011] Embodiments of the present disclosure will be better understood and readily apparent to those skilled in the art from the following description, given by way of example only, taken in conjunction with the drawings in which:

[0012] [Figure 1A] 1 shows a schematic diagram of uplink and downlink single-user multiple-input multiple-output (MIMO) communication between an access point (AP) and a station (STA) in a MIMO wireless network. [Figure 1B] 1 shows a schematic diagram of downlink Multi-User MIMO (MU-MIMO) between an AP and multiple STAs in a MIMO wireless network. [Figure 1C] 1 shows a schematic diagram of uplink MU-MIMO communication between an AP and multiple STAs in a MIMO wireless network. [Figure 1D] 1 shows the format of a PPDU (Physical Layer Protocol Data Unit) used for downlink multi-user communication between an AP and multiple STAs in a HE WLAN. [Figure 1E] The HE-SIG-B (HE SIGNAL B) field is shown in more detail. [Figure 1F] 1 shows the format of a PPDU used for uplink multi-user communication between an AP and multiple STAs in a HE WLAN. [Figure 2A] Indicates EHT MU PPDU. [Figure 2B] Indicates EHT TB (Trigger Based) PPDU. [Figure 3A] 1 illustrates a simplified example of a communications device, which may be implemented as an AP or STA according to various embodiments of the present disclosure, configured for user-specific persistent assignment (PA). [Figure 3B] 1 shows a flow diagram illustrating a communication method according to various embodiments. [Figure 3C] 1 shows a flow diagram illustrating a communication method according to various embodiments. [Figure 3D] 1 shows a flow diagram illustrating a communication method according to various embodiments. [Figure 3E] 1 shows a flow diagram illustrating a communication method according to various embodiments. [Figure 4A] 1 shows a flowchart illustrating communication between an AP and multiple STAs over an uplink user-specific PA on a TXOP (Transmit Opportunity) in accordance with various embodiments. [Figure 4B] 1 shows a flowchart illustrating communication between an AP and multiple STAs over uplink user-specific PAs over two TXOPs according to various embodiments. [Figure 5A] 1 shows the format of an EHT Basic Trigger frame used for uplink multi-user communication between an AP and multiple STAs in an EHT WLAN according to a first embodiment. [Figure 5B] 1 shows the format of an EHT Basic Trigger frame used for uplink multi-user communication between an AP and multiple STAs in an EHT WLAN according to a first embodiment. [Figure 5C] 10 shows a PA Trigger frame used in uplink multi-user communication according to the first or third embodiment. [Figure 5D] 10 illustrates a data or management frame carrying a PA Control subfield used for uplink multi-user communication according to the first or third embodiment. [Figure 5E] 1 illustrates a MU-MIMO allocation with three user-specific allocations according to various embodiments. [Figure 6A] 10 shows a flowchart illustrating processing of an EHT Basic Trigger frame received at a STA according to the first embodiment. [Figure 6B] 10 shows a flowchart illustrating processing of a PA Trigger frame received at a STA according to the first embodiment. [Figure 6C] 10 shows a flowchart illustrating the processing of a received data or management frame carrying a PA Control subfield received at a STA according to a first embodiment. [Figure 7A] 10 shows the format of an EHT Basic Trigger frame used for uplink multi-user communication between an AP and multiple STAs in an EHT WLAN according to a second embodiment. [Figure 7B] 10 shows the format of an EHT Basic Trigger frame used for uplink multi-user communication between an AP and multiple STAs in an EHT WLAN according to a second embodiment. [Figure 7C] 10 shows a PA Trigger frame used in uplink multi-user communication according to the second or fourth embodiment. [Figure 7D] 10 illustrates a data or management frame carrying a PA Control subfield for use in uplink multi-user communication according to the second or fourth embodiment. [Figure 8A] 10 shows a flowchart illustrating processing of an EHT Basic Trigger frame received at a STA according to a second embodiment. [Figure 8B] 10 shows a flowchart illustrating processing of a PA Trigger frame received at a STA according to the second or fourth embodiment. [Figure 8C] 10 shows a flowchart illustrating the processing of a received data or management frame carrying a PA Control field at a STA according to the second or fourth embodiment. [Figure 9A] 1 shows a flowchart illustrating communication between an AP and multiple STAs over an uplink user-specific PA over a TXOP according to various embodiments. [Figure 9B] 1 shows a flowchart illustrating communication between an AP and multiple STAs over uplink user-specific PAs over two TXOPs according to various embodiments. [Figure 10A] 10 shows the format of a PA Announcement frame used for uplink or downlink multi-user communication between an AP and multiple STAs in an EHT WLAN according to a third embodiment. [Figure 10B]10 shows the format of an EHT Basic Trigger frame used for uplink multi-user communication between an AP and multiple STAs in an EHT WLAN according to a third embodiment. [Figure 11] 10 shows a flowchart illustrating processing of an EHT Basic Trigger frame received at a STA according to a third embodiment. [Figure 12] 10 shows the format of a PA Announcement frame used for uplink or downlink multi-user communication between an AP and multiple STAs in an EHT WLAN according to a fourth embodiment. [Figure 13] 10 shows a flowchart illustrating processing of an EHT Basic Trigger frame received at a STA according to a fourth embodiment. [Figure 14A] 10 shows a flow diagram illustrating communication between an AP and a STA via a downlink user-specific PA according to the third or fourth embodiment. [Figure 14B] 10 shows a flow diagram illustrating communication between an AP and a STA via a downlink user-specific PA according to the third or fourth embodiment. [Figure 15A] 10 illustrates the structure of a User Info field for downlink user-specific PA with non-MU-MIMO allocation according to the third or fourth embodiment. [Figure 15B] 10 shows the structure of a User Info field for downlink user-specific PA for MU-MIMO allocation according to the third or fourth embodiment. [Figure 16A] 1 shows a table of how the number of EHT-SIG-B content channels depends on the channel bandwidth (CBW) and the value of L. [Figure 16B] 10 shows a diagram of the mapping of one or two EHT-SIG-B content channels in a 40 MHz EHT MU PPDU. [Figure 16C] 1 shows a diagram of the mapping of two EHT-SIG-B content channels in an 80 MHz EHT MU PPDU. [Figure 16D]1 shows a diagram of the mapping of two EHT-SIG-B content channels in an 80+80 MHz or 160 MHz EHT MU PPDU. [Figure 16E] 1 shows a diagram of the mapping of two EHT-SIG-B content channels in a 160+160 MHz or 320 MHz EHT MU PPDU. [Figure 17A] 10 shows an EHT-SIG-B field according to a third or fourth embodiment. [Figure 17B] 3C illustrates an EHT-SIG-B field according to the embodiment shown in FIG. 3B. [Figure 18A] This shows the mapping between the PA Present subfield in the EHT SIGNAL A (EHT-SIG-A) field, the RU Allocation subfield, the Center 26-Tone RU subfield, and the PA Bitmap subfield in the EHT-SIG-B field. [Figure 18B] This shows the mapping between the PA Present subfield in the EHT SIGNAL A (EHT-SIG-A) field, the RU Allocation subfield, the Center 26-Tone RU subfield, and the PA Bitmap subfield in the EHT-SIG-B field. [Figure 19A] 10 shows a first specific example of the coding configuration of the Common field according to the third or fourth embodiment. [Figure 19B] 10 shows a second specific example of the coding configuration of the Common field according to the third or fourth embodiment. [Figure 19C] 3C shows a first specific example of the coding structure of the Common field according to the embodiment shown in FIG. 3B. [Figure 19D] 3C shows a second specific example of the coding structure of the Common field according to the embodiment shown in FIG. 3B. [Figure 19E] 3D shows a first specific example of the coding structure of the Common field according to the embodiment shown in FIG. 3C. [Figure 19F]3D shows a second specific example of the coding structure of the Common field according to the embodiment shown in FIG. 3C. [Figure 20A] 3D shows a diagram of User Specific field overhead reduction according to the embodiment shown in FIG. 3C. [Figure 20B] 3D shows a diagram of User Specific field overhead reduction in another example according to the embodiment shown in FIG. 3C. [Figure 20C] 3D shows a diagram of User Specific field overhead reduction in another example according to the embodiment shown in FIG. 3C. [Figure 21] 10 shows a flowchart illustrating the processing of a received EHT MU PPDU at a STA according to the third or fourth embodiment. [Figure 22] 13 shows a flowchart illustrating communication between an AP and a STA via a downlink user-specific PA according to a fifth embodiment. [Figure 23] 10 shows an EHT-SIG-B field according to a fifth embodiment. [Figure 24A] 10 shows a first specific example of the coding configuration of the Common field according to the fifth embodiment. [Figure 24B] 10 shows a second specific example of the coding structure of the Common field according to the fifth embodiment. [Figure 25] 10 shows a diagram of User Specific field overhead reduction according to a fifth embodiment. [Figure 26] 13 shows a flowchart illustrating processing of a received EHT MU PPDU at a STA according to a fifth embodiment. [Figure 27] 1 illustrates the configuration of a communication device such as an AP according to various embodiments. [Figure 28] 1 illustrates the configuration of a communication device such as a STA according to various embodiments.

[0013] Those skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and are not necessarily drawn to scale. For example, the size of some of the elements in the figures, block diagrams or flowcharts may be exaggerated relative to other elements to help understand the present embodiments accurately. DETAILED DESCRIPTION OF THE INVENTION

[0014] Some embodiments of the present disclosure will now be described, by way of example only, with reference to the drawings in which like reference numerals and letters refer to similar or equivalent elements.

[0015] In the following paragraphs, specific exemplary embodiments are described, with particular reference to an access point (AP) and a station (STA) for uplink or downlink persistent assignment (PA) in a multiple-input multiple-output (MIMO) wireless network.

[0016] In the context of IEEE 802.11 (Wi-Fi) technology, a station, interchangeably referred to as a STA, is a communication device capable of using the 802.11 protocol. Based on the IEEE 802.11-2016 definition, a STA can be any device that includes an IEEE 802.11-compliant medium access control (MAC) and physical layer (PHY) interface with a wireless medium (WM).

[0017] For example, a STA may be a laptop, desktop personal computer (PC), personal digital assistant (PDA), access point, or Wi-Fi phone in a wireless local area network (WLAN) environment. A STA may be fixed or mobile. In a WLAN environment, the terms "STA," "wireless client," "user," "user device," and "node" are often used interchangeably.

[0018] Similarly, an AP, which may be referred to interchangeably as a Wireless Access Point (WAP) in the context of IEEE 802.11 (Wi-Fi) technology, is a communications device that allows STAs in a WLAN to connect to a wired network. An AP typically connects to a router (via the wired network) as a standalone device, but it can also be integrated with or used in a router.

[0019] As mentioned above, a STA in a WLAN can act as an AP at different times, and vice versa. This is because a communication device in the context of IEEE 802.11 (Wi-Fi) technology may include both STA and AP hardware components. In this manner, the communication device may switch between STA mode and AP mode based on actual WLAN conditions and / or requirements.

[0020] In a MIMO wireless network, "multiple" refers to multiple antennas used simultaneously for transmission and reception over a wireless channel. In this regard, "multiple-input" refers to multiple transmitter antennas that input wireless signals into the channel, and "multiple-output" refers to multiple receiver antennas that receive wireless signals from the channel to the receiver. For example, in an N×M MIMO network system, N is the number of transmitter antennas and M is the number of receiver antennas, and N may or may not be equal to M. For simplicity, the respective numbers of transmitter antennas and receiver antennas will not be further discussed in this disclosure.

[0021] In a MIMO wireless network, single-user communication and multi-user communication can be deployed for communication between communication devices such as APs and STAs.

[0022] 1A shows a schematic diagram of single-user MIMO communication 100 between an AP 102 and a STA 104 in a MIMO wireless network. As shown, the MIMO wireless network may include one or more STAs (e.g., STA 104, STA 106, etc.). In single-user MIMO communication 100, the AP 102 transmits multiple spatial streams using multiple antennas (e.g., four antennas as shown in FIG. 1A), all of which are directed to a single communication device, i.e., the STA 104. For simplicity, the multiple spatial streams directed to the STA 104 are shown as a grouped data transmission arrow 108 directed to the STA 104.

[0023] The single-user MIMO communication 100 can be configured for bidirectional transmission. As shown in FIG. 1A, in the single-user MIMO communication 100, the STA 104 transmits multiple spatial streams using multiple antennas (e.g., two antennas as shown in FIG. 1A), and all of these spatial streams are directed to the AP 102. For simplicity, the multiple spatial streams directed to the AP 102 are shown as a grouped data transmission arrow 110 directed to the AP 102.

[0024] Additionally, the single-user MIMO communication 100 shown in FIG. 1A allows for both uplink and downlink single-user transmissions in a MIMO wireless network.

[0025] FIG. 1B shows a schematic diagram of downlink multi-user MIMO (MU-MIMO) communication 120 between an AP 122 and multiple STAs 124, 126, 128 in a MIMO wireless network.

[0026] A MIMO wireless network may include one or more STAs (e.g., STA 124, STA 126, STA 128, etc.). In downlink MU-MIMO communication 120, AP 122 uses multiple antennas via spatial mapping or precoding techniques to simultaneously transmit multiple streams to STAs 124, 126, and 128 in the network. For example, two spatial streams may be directed to STA 126, another spatial stream may be directed to STA 124, and yet another spatial stream may be directed to STA 128. For simplicity, the two spatial streams directed to STA 126 are shown as grouped data transmission arrow 132, the spatial stream directed to STA 124 is shown as data transmission arrow 130, and the spatial stream directed to STA 128 is shown as data transmission arrow 134.

[0027] FIG. 1C shows a schematic diagram of uplink MU-MIMO communication 140 between an AP 142 and multiple STAs 144, 146, 148 in a MIMO wireless network.

[0028] A MIMO wireless network may include one or more STAs (e.g., STA 144, STA 146, STA 148, etc.). In uplink MU-MIMO communication 140, STAs 144, 146, and 148 simultaneously transmit respective streams to an AP 142 in the network using their respective antennas via spatial mapping or precoding techniques. For example, two spatial streams may be directed from STA 146 to the AP 142, another spatial stream may be directed from STA 144 to the AP 142, and yet another spatial stream may be directed from STA 148 to the AP 142. For simplicity, the two spatial streams directed from STA 146 to the AP 142 are shown as grouped data transmission arrow 152, the spatial stream directed from STA 144 to the AP 142 is shown as data transmission arrow 150, and the spatial stream directed from STA 148 to the AP 142 is shown as data transmission arrow 154.

[0029] Due to the packet / PPDU (Physical Layer Protocol Data Unit) based transmission and distributed MAC scheme in 802.11 WLAN, there is no time scheduling (e.g., periodic time slot allocation for data transmission like TDMA (Time Division Multiple Access)) in 802.11 WLAN. Frequency and spatial resource scheduling is performed on a packet basis. In other words, resource allocation information is PPDU-based.

[0030] 1D shows the format of a PPDU 160 used for downlink multi-user communication between an AP and multiple STAs in an HE WLAN, such as Orthogonal Frequency Division Multiple Access (OFDMA) transmissions, including MU-MIMO transmissions in a single Resource Unit (RU) and full-bandwidth MU-MIMO transmissions. Such a PPDU 160 is referred to as an HE MU PPDU 160.

[0031] The HE MU PPDU 160 may include a non-High Throughput Short Training Field (L-STF), a non-High Throughput Long Training Field (L-LTF), a non-High Throughput SIGNAL Field (L-SIG), a Repeated L-SIG (RL-SIG), an HE SIGNAL A (HE-SIG-A) field 162, an HE SIGNAL B (HE-SIG-B) field 166, an HE Short Training Field (HE-STF), an HE Long Training Field (HE-LTF), a Data field 170, and a Packet Extension (PE) field.

[0032] In the HE MU PPDU 160, the HE-SIG-B field 166 provides OFDMA and MU-MIMO resource allocation information, allowing STAs to retrieve the corresponding resources to be used in the Data field 170, as indicated by arrow 168. The HE-SIG-A field 162 contains information necessary to decode the HE-SIG-B field 166, such as the MCS of the HE-SIG-B, the number of HE-SIG-B symbols, etc., as indicated by arrow 164.

[0033] 1E shows in more detail the HE-SIG-B field 166. The HE-SIG-B field 166 includes (or consists of) a Common field 172 followed by a User Specific field 174, which, if present, are together referred to as the HE-SIG-B content channel.

[0034] The HE-SIG-B field 166 includes an RU Allocation subfield that indicates RU information for each allocation. The RU information includes the RU location in the frequency domain, an indication of the RU allocated for non-MU-MIMO or MU-MIMO allocation, and the number of users in the MU-MIMO allocation. The Common field 172 does not exist in the case of full-bandwidth MU-MIMO transmission. In this case, the RU information (e.g., the number of users in the MU-MIMO allocation) is signaled in the HE-SIG-A field 162.

[0035] The User Specific field 174 includes (or consists of) one or more User fields for non-MU-MIMO and / or MU-MIMO allocations. The User fields include user information indicating user-specific allocations (i.e., user-specific allocation information). In the example shown in FIG. 1E, the User Specific field 174 includes five user fields (User Field 0,...,User Field 4), where the user-specific allocation information for an allocation (Allocation 0) is provided by User Field 0, the user-specific allocation information for a further allocation (Allocation 1 with three MU-MIMO users) is provided by User Field 1, User Field 2, and User Field 3, and the user-specific allocation information for a still further allocation (Allocation 2) is provided by User Field 4. Note that the MU-MIMO allocation (Allocation 1) comprises three user-specific allocations indicated by User Field 1, User Field 2, and User Field 3, respectively.

[0036] 1F shows the format of a PPDU 180 used for uplink multi-user communication between an AP and multiple STAs in an HE WLAN. Such a PPDU 180 is referred to as an HE TB (Trigger Based) PPDU 180.

[0037] The HE TB PPDU 180 may include an L-STF, an L-LTF, an L-SIG, an RL-SIG, an HE-SIG-A field 182, an HE-STF, an HE-LTF, a Data field, and a PE field.

[0038] The HE TB PPDU 180 is used for uplink multi-user transmissions in response to frames carrying trigger information. Instead of using the HE-SIG-B field, the information required for an uplink multi-user transmission from one or more STAs is carried in the frame requesting this transmission. In a typical transmission of the HE TB PPDU 180, the HE-SIG-A related information is copied into the HE-SIG-A field 182 of the HE TB PPDU 180 from a previous frame carrying trigger information.

[0039] When the MIMO wireless network has extremely high throughput, such as an EHT WLAN, the multi-user PPDU used for downlink multi-user transmission may be referred to as an EHT MU PPDU 200 as shown in FIG. 2A, and the multi-user PPDU used for uplink multi-user transmission may be referred to as an EHT TB PPDU as shown in FIG. 2B.

[0040] 2A illustrates an EHT MU PPDU 200. The EHT MU PPDU 200 may include an L-STF, an L-LTF, an L-SIG, a Format Identification Field (FIF) 201, an EHT SIGNAL A (EHT-SIG-A) field 202, an EHT SIGNAL B (EHT-SIG-B) field 206, an EHT-STF, an EHT-LTF, a Data field 210, and a PE field. It should be understood that if the IEEE 802.11 Working Group uses a new name instead of "EHT WLAN" for next-generation WLANs with extremely high throughput, the prefix "EHT" in the above fields may change accordingly. The FIF 201 is primarily used to identify the format of the EHT PPDU. The EHT-SIG-A field 202 contains information needed to decode the EHT-SIG-B field 206, such as the MCS of the EHT-SIG-B, the number of EHT-SIG-B symbols, etc., as indicated by arrow 204. The EHT-SIG-B field 206 provides OFDMA and MU-MIMO resource allocation information, allowing STAs to look up the corresponding resources to be used in the Data field 210, as indicated by arrow 208. Similar to FIG. 1D , the EHT-SIG-B field 206 includes (or consists of) a Common field, followed by a User Specific field, if present, which together are referred to as the EHT-SIG-B content channel.

[0041] Due to the maximum number of spatial streams of 16, the maximum channel bandwidth (CBW) of 320 MHz, and multi-band operation in EHT WLANs, the number of assignments and / or users supported in an EHT MU PPDU can be significantly increased. As a result, an EHT MU PPDU can have a much larger signaling overhead than an HE MU PPDU. Apparatus and methods according to various embodiments can advantageously reduce the signaling overhead, especially when the CBW exceeds 20 MHz.

[0042] 2B shows the format of the EHT TB PPDU 212. The EHT TB PPDU 212 may include an L-STF, an L-LTF, an L-SIG, an FIF, an EHT-SIG-A field 214, an EHT-STF, an EHT-LTF, a Data field, and a PE field.

[0043] The EHT TB PPDU 212 is used for uplink multi-user transmissions in response to frames carrying trigger information in EHT WLANs. Instead of using the EHT-SIG-B field, information required for an uplink multi-user transmission from one or more STAs is carried in the frame requesting that transmission. In a typical transmission of the EHT TB PPDU 212, EHT-SIG-A related information is copied from a previous frame carrying trigger information into the EHT-SIG-A field 214 of the EHT TB PPDU 212.

[0044] Due to the maximum number of spatial streams of 16, the maximum CBW of 320 MHz, and multi-band operation in an EHT WLAN, the number of allocations and / or the number of users supported in an EHT TB PPDU can be significantly increased. As a result, frames requesting EHT TB PPDU transmissions can have much larger signaling overhead than frames requesting HE TB PPDU transmissions. Apparatus and methods according to various embodiments can advantageously reduce signaling overhead, especially when the CBW is greater than 20 MHz.

[0045] In addition to dynamic allocation, EHT WLANs also support user-specific persistent allocation (PA), which allows for repeated transmissions within a period of time with reduced control signaling requirements, according to various embodiments. User-specific PA is particularly suited for traffic such as Voice over Internet Protocol (VoIP).

[0046] 3A shows a schematic partial cross-sectional view of a communication device 300 according to various embodiments. The communication device 300 may be implemented as an AP or a STA according to various embodiments.

[0047] As shown in Figure 3A, communications device 300 may include circuitry 314, at least one wireless transmitter 302, at least one wireless receiver 304, and at least one antenna 312 (for simplicity, only one antenna is shown in Figure 3A for illustrative purposes). Circuitry 314 may include at least one controller 306 for use in software- and hardware-assisted execution of tasks that the at least one controller 306 is designed to perform, including control of communications with one or more other communications devices in a MIMO wireless network. Circuitry 314 may further include at least one transmit signal generator 308 and at least one receive signal processor 310. The at least one controller 306 includes at least one transmission signal generator 308 for generating PPDUs (e.g., an EHT MU PPDU or PPDU including a PA Announcement frame, an EHT Basic Trigger frame, a PA Trigger frame, a frame carrying a PA Control subfield, or a Multi-STA BlockAck frame, if the communication device 300 is an AP, and an EHT TB PPDU or PPDU including a BlockAck frame, if the communication device 300 is an STA) to be transmitted to one or more other communication devices via the at least one wireless transmitter 302, and a transmission signal generator 308 for generating PPDUs (e.g., an EHT TB PPDU or PPDU including a BlockAck frame, if the communication device 300 is an AP, and an EHT MU PPDU or PPDU including a PA Announcement frame, an EHT Basic Trigger frame, a PA Trigger frame, a frame carrying a PA Control subfield, or a Multi-STA BlockAck frame, if the communication device 300 is an STA, if the communication device 300 is an STA) to be received from one or more other communication devices via the at least one wireless receiver 304 under the control of the at least one controller 306. and at least one receive signal processor 310 for processing the PPDU or PPDUs.The at least one transmit signal generator 308 and the at least one receive signal processor 310 may be stand-alone modules of the communication device 300 that communicate with the at least one controller 306 for the above-described functions, as shown in FIG. 3A . Alternatively, the at least one transmit signal generator 308 and the at least one receive signal processor 310 may be included in the at least one controller 306. Those skilled in the art will appreciate that the configuration of these functional modules is flexible and may vary according to actual needs and / or requirements. Data processing, storage, and other related control devices may be provided on an appropriate circuit board and / or chipset. In various embodiments, in operation, the at least one wireless transmitter 302, the at least one wireless receiver 304, and the at least one antenna 312 may be controlled by the at least one controller 306.

[0048] During operation, the communications device 300 provides functionality required for downlink user-specific PA. For example, the communications device 300 may be an AP, and the circuit 314 (e.g., at least one transmit signal generator 308 of the circuit 314) may generate a transmit signal including a Common field (e.g., in an EHT-SIG-B field of an EHT MU PPDU), a User Specific field (e.g., in an EHT-SIG-B field of an EHT MU PPDU), and a Data field (e.g., in an EHT MU PPDU), where the Common field includes RU information for one or more user-specific assignments in the Data field, and the User Specific field includes one or more user information fields, each indicating a user-specific assignment among the one or more user-specific assignments in the Data field. The wireless transmitter 302 may transmit the generated transmit signal during operation. The User Specific field may not include user information for downlink user-specific PA, including initial or repeated transmissions among one or more user-specific assignments. In other words, user information for downlink user-specific PAs that include initial or repeat transmissions during one or more user-specific assignments may not be included in the User Specific field. For example, only user information for downlink non-user-specific PAs may be included in the User Specific field. This may advantageously reduce communication overhead.

[0049] The communication device 300 may be a STA, and the wireless receiver 304 may, during operation, receive a transmission signal (e.g., an EHT MU PPDU) including a Common field, a User Specific field, and a Data field, where the Common field includes RU information for one or more user-specific assignments in the Data field, and the User Specific field includes one or more pieces of user information, each indicating a user-specific assignment among the one or more user-specific assignments in the Data field. The circuitry 314 may, during operation, process the received transmission signal. The User Specific field may not include user information for downlink user-specific PAs, including initial or repeat transmissions among the one or more user-specific assignments.

[0050] The communications device 300 provides functionality required for uplink user-specific PA during operation. For example, the communications device 300 may be an AP, and the circuit 314 (e.g., at least one transmit signal generator 308 of the circuit 314) may generate a transmit signal including a frame for requesting EHT TB PPDU transmissions from one or more STAs during operation, the frame including one or more pieces of user-specific resource allocation information, each indicating a user-specific allocation in a Data field of the requested EHT TB PPDU. The wireless transmitter 302 may transmit the generated transmit signal during operation. The frame may be devoid of user-specific resource allocation information for an uplink user-specific PA including an initial or repeat transmission. In other words, user-specific resource allocation information for an uplink user-specific PA including an initial or repeat transmission may not be included in the frame. For example, only user-specific resource allocation information for an uplink non-user-specific PA may be included in the frame. This may advantageously reduce communication overhead.

[0051] For example, the communication device 300 may be a STA, and the wireless receiver 304 may receive a transmission signal (e.g., a frame requesting an EHT TB PPDU transmission from one or more STAs) during operation. The transmission signal includes one or more pieces of user-specific resource allocation information, each indicating a user-specific allocation in a Data field of the requested EHT TB PPDU. The circuit 314 may process the received transmission signal during operation. The frame may be devoid of user-specific resource allocation information for an uplink user-specific PA that includes an initial or repeat transmission. In other words, user-specific resource allocation information for an uplink user-specific PA that includes an initial or repeat transmission may not be included in the frame. For example, only user-specific resource allocation information for an uplink non-user-specific PA may be included in the frame. This may advantageously reduce communication overhead.

[0052] For example, the communications device 300 may be an AP, and the circuit 314 (e.g., the at least one transmit signal generator 308 of the circuit 314) may, during operation, generate a first transmit signal including user information for multiple users to downlink MU-MIMO assignments, and further generate a second transmit signal including a Common field, a User Specific field, and a Data field, each indicating a user-specific assignment, including a transmission of a downlink MU-MIMO assignment. The wireless transmitter 302 may, during operation, transmit the first transmit signal and the second transmit signal, wherein it is determined whether the user-specific assignment of downlink MU-MIMO assignments is persistent.

[0053] 3B shows a flow diagram 330 illustrating a communication method according to various embodiments. At 332, a transmission signal may be generated. The transmission signal may include a Common field, a User Specific field, and a Data field, where the Common field includes RU information for each of the one or more allocations in the Data field, and the User Specific field includes one or more pieces of user information, each indicating a user-specific allocation among the one or more allocations in the Data field. At 334, the generated transmission signal may be transmitted. The User Specific field may be absent from at least one piece of user information for persistent allocations that include repeated transmissions among one or more allocations.

[0054] According to various embodiments, a communication method may include receiving a transmission signal including a Common field, a User Specific field, and a Data field, wherein the Common field includes RU information for each of the one or more allocations in the Data field, the User Specific field includes one or more pieces of user information, each indicating a user-specific allocation among the one or more allocations in the Data field, and the User Specific field may be absent from at least one of the user information for a persistent allocation including repeated transmissions among the one or more allocations.

[0055] FIG. 3C shows a flow diagram 350 illustrating a communication method according to various embodiments. In step 352, a transmission signal may be generated. The transmission signal may include at least one signal field content channel and a data field, each of which may include N fields and a repeat transmission bitmap subfield consisting of N bitmaps (N=1, 2, 4, or 8), each of the N fields in the RU assignment subfield indicating RU information for one or more allocations within a corresponding tone range in the Data field, and the nth (n=1, 2, . . . , N) bitmap in the repeat transmission bitmap subfield indicating whether each of the one or more allocations indicated by the nth field in the RU assignment subfield includes a repeat transmission. In step 354, the generated transmission signal is transmitted.

[0056] 3D shows a flow diagram 360 illustrating a method of communication according to various embodiments. In step 362, a frame may be generated that includes identification information that identifies the uplink PA. In step 364, the generated frame is transmitted.

[0057] 3E shows a flow diagram 390 illustrating a method of communication in accordance with various embodiments. At step 392, a first transmission is generated that includes user information for multiple users for downlink MU-MIMO assignments, each indicating a user-specific assignment. At step 394, a second transmission is generated that includes a Common field, a User Specific field, and a Data field, and that includes a transmission of the downlink MU-MIMO assignment. At step 396, the first and second transmissions are transmitted, where it is determined whether the user-specific assignments of downlink MU-MIMO assignments are persistent.

[0058] FIG. 4A shows a flowchart 400 illustrating communication between an AP 402 and multiple STAs (404, 406) using an uplink user-specific PA via a transmission opportunity (TXOP) in accordance with various embodiments. A contention-based channel access procedure, e.g., an Enhanced Distributed Channel Access (EDCA) procedure, is indicated by block 408, and Short Interframe Spacings (SIFS) 410 are shown. The AP 402 may generate a first frame 412 including complete information of the uplink user-specific PA to request an initial transmission of the uplink user-specific PA to the STA 406. The complete PA information may include identification information and user-specific resource allocation information. In one embodiment, the identification information may be a PA identifier (PAID) of the uplink user-specific PA. In another embodiment, the identification information may be RU allocation information and user identification information for the uplink user-specific PA. In yet another embodiment, the identification information may be RU allocation information and spatial stream (SS) allocation information for the uplink user-specific PA. The first frame 412 may also include complete information of the uplink user-specific PA to request an initial transmission of the uplink user-specific PA for the STA 404. The AP 402 may transmit the generated first frame 412 to the STAs 404 and 406.

[0059] At 414, the STA 406 may receive the first frame 412, store the complete information of the uplink user-specific PA (i.e., the identity of the intended uplink user-specific PA for the STA 406 and the user-specific resource allocation information), and transmit an EHT TB PPDU 418 to the AP 402 accordingly. The STA 404 may also receive and store the complete information regarding the uplink user-specific PA (i.e., the identity of the intended uplink user-specific PA for the STA 404 and the user-specific resource allocation information), and transmit an EHT TB PPDU 416 to the AP 402 accordingly. The EHT TB PPDUs 416 and 418 may have the same format as the EHT TB PPDU 212 shown in FIG. 2B . The AP 402 may receive the EHT TB PPDUs 416 and 418 and transmit a Multi-STA BlockAck (Block Acknowledgement) frame 420 to the STAs 404 and 406. The AP 402 may then request repeated transmission of the uplink user-specific PA for the STA 404 and repeated transmission of the uplink user-specific PA for the STA 406 by transmitting a second frame 422. The second frame 422 may carry identification information for the uplink user-specific PA for the STA 404 and identification information for the uplink user-specific PA for the STA 406. In various embodiments, the identification information for the uplink user-specific PA is included in the frame body of the second frame 422 to request repeated transmission of the uplink user-specific PA, and the second frame 422 does not have user-specific resource allocation information for the uplink user-specific PA. In various embodiments, the identification information is included in the MAC header of the second frame 422 to request repeated transmission of the uplink user-specific PA, and the second frame 422 does not have user-specific resource allocation information for the uplink user-specific PA.

[0060] At 424, the STA 406 may prepare an EHT TB PPDU 428 based on the stored user-specific resource allocation for the uplink user-specific PA and transmit the EHT TB PPDU 428 to the AP 402. The EHT TB PPDU 428 includes a repeated transmission of the uplink user-specific PA for the STA 406. The STA 404 may also prepare an EHT TB PPDU 426 based on the stored user-specific resource allocation for the uplink user-specific PA and transmit the EHT TB PPDU 426 to the AP 402. The EHT PPDU 426 includes a repeated transmission of the uplink user-specific PA for the STA 404. The EHT TB PPDUs 426 and 428 may have the same format as the EHT TB PPDU 212 shown in FIG. 2B. The AP 402 may receive the EHT TB PPDUs 426 and 428 and transmit a Multi-STA BlockACK frame 430 to the STAs 404 and 406. As shown in FIG. 4A, the repeated transmission of the uplink user-specific PA may occur within the same TXOP as the initial transmission of the uplink user-specific PA. The repeated transmission may also occur in a different TXOP from the initial transmission of the uplink user-specific PA, as shown in FIG. 4B. That is, in one example, the uplink user-specific PA may exist until the end of the current TXOP. In another example, the uplink user-specific PA may exist for a determined number of service periods or beacon intervals. In FIG. 4B, the second frame 422 is transmitted by the AP 402 in a different TXOP from the first frame 412, and therefore, the repeated transmissions requested by the second frame 422 (e.g., the uplink user-specific PA transmissions included in EHT TB PPDUs 426 and 428) also occur in a different TXOP from the first frame 412. It can be understood that the transmission of the second frame 422 occurs within the period in which the uplink user-specific PA for the STAs 404 and 406 exists.

[0061] 5A and 5B show the format of an EHT Basic Trigger frame 500 used for uplink multi-user communication between an AP and multiple STAs in an EHT WLAN according to a first embodiment. The EHT Basic Trigger frame 500 is a modification of an existing Trigger frame and may be used as the first frame 412 in FIGS. 4A and 4B. The EHT Basic Trigger frame 500 identifies an uplink user-specific PA using its PAID. The EHT Basic Trigger frame 500 may include a Frame Control field, a Duration field, a Recipient STA Address (RA) field, a Transmitting STA Address (TA) field, one or more User Info fields such as a Common Info field 502 and a User Info field 504, a Padding field, and a Frame Check Sequence (FCS) field. The Frame Control field, Duration field, RA field, and TA field may be grouped in the MAC header of the EHT Basic Trigger frame 500. A Common Info field 502 , one or more User Info fields 504 and a Padding field may be grouped in the frame body of the EHT Basic Trigger frame 500 .

[0062] 5A also shows the Common Info field 502 in more detail. The Common Info field 502 contains common parameters for all STAs participating in the EHT TB PPDU transmission requested by the EHT Basic Trigger frame 500. The Common Info field 502 includes (or consists of) a Trigger Type field 506, an Uplink (UL) Length field, a More Trigger Frame (TF) field, a Carrier Sense (CS) Required field, a UL Bandwidth (BW) field, a Guard Interval (GI) and LTF Type field, a MU-MIMO LTF Mode field, a Number of HE-LTF Symbols and Midamble Periodicity field, a UL Space Time Block Coding (STBC) field, a Low Density Parity Check (LDPC) Extra Symbol Segment field, an AP Transmission Power (TX) field, a Pre-Forward Error Correction (FEC) Padding Factor field, a PE Disambiguity field, a Doppler field, a UL HE-SIG-A2 Reserved field, and a Trigger Dependent Common Info field 508. The Trigger Dependent Common Info field 508 may include (or consist of) a Number of PAIDs field and a PAID Tuples field. The Number of PAIDs field indicates the number of PAID subfields included in the PAID Tuples field. Alternatively, the Trigger Dependent Common Info field 508 may include a Starting PAID field, a PAID Bitmap Size field, and a PAID Bitmap field. The PAID Bitmap Size field indicates the bit width of the PAID Bitmap field.The Starting PAID field contains the starting PAID in the PAID Bitmap field. The PAID Bitmap field, together with the Starting PAID field, indicates the PAID. The EHT Basic Trigger frame 500 requests repeated transmission of an uplink user-specific PA using its PAID contained in the Trigger Dependent Common Info field 508. The Trigger Type field 506 may be assigned an arbitrary value to indicate that the Trigger frame 500 is an EHT Basic Trigger frame. In various embodiments below, the Trigger Type field 506 is assigned an arbitrary value of 8 to indicate that the Trigger frame 500 is an EHT Basic Trigger frame.

[0063] 5B shows the User Info field 504 in more detail. The User Info field 504 includes an AID12 field, an RU Allocation field, a UL FEC Coding Type field, a UL Modulation and Coding Scheme (MCS) field, a UL Dual Carrier Modulation (DCM) field, an SS Allocation field, a UL Target Receive Signal Strength Indicator (RSSI) field, and a Trigger Dependent User Info field 512. The Trigger Dependent User Info field 512 may include (or consist of) a 1-bit PA Flag subfield, a PAID subfield 516, an MPDU MU Spacing Factor subfield, a Traffic Identifier (TID) Aggregation Limit subfield, and a Preferred Access Category (AC) subfield. Alternatively, the Trigger Dependent User Info field 512 may include (or consist of) the PAID subfield 516, an MPDU MU Spacing Factor subfield, a TID Aggregation Limit subfield, and a Preferred Access Category (AC) subfield. The RU Allocation field, UL FEC Coding Type field, UL MCS field, UL DCM field, SS Allocation field, UL Target RSSI field, MPDU MU Spacing Factor subfield, TID Aggregation Limit subfield, and Preferred AC subfield constitute user-specific resource allocation information 514 of the User Info field 504.The user-specific resource allocation information 514 may be acquired and stored by the STA for the initial or repeated uplink user-specific PA transmission, and an EHT TB PPDU based on the stored user-specific resource allocation information 514 is transmitted to the AP requesting the uplink user-specific PA transmission.

[0064] As described above, the User Info field 504 may include a PA Flag subfield and a PAID subfield 516. The PA Flag subfield (e.g., 1 bit) indicates whether the User Info field 504 corresponds to an uplink user-specific PA, and the PAID subfield 516 (e.g., 7 bits) indicates the PAID of the uplink user-specific PA. A User Info field with the PA Flag subfield set to 0 indicates that the User Info field does not correspond to an uplink user-specific PA. In this case, the PAID subfield 516 is reserved. On the other hand, a User Info field with the PA Flag subfield set to 1 indicates that the User Info field corresponds to an uplink user-specific PA. In this case, the PAID subfield 516 indicates the PAID of the uplink user-specific PA. Furthermore, the PA Flag subfield of the User Info field for random access is set to 0. That is, an uplink user-specific PA for random access is not permitted.

[0065] Alternatively, the User Info field 504 may include a PAID subfield 516 (e.g., 8 bits) indicating whether the User Info field 504 corresponds to an uplink user-specific PA or the PAID of the uplink user-specific PA corresponding to the User Info field. A User Info field with the PAID subfield 516 set to 0 indicates that the User Info field does not correspond to an uplink user-specific PA. A User Info field with the PAID subfield 516 set to any other value (e.g., 1 to 255) indicates the PAID of an uplink user-specific PA. Furthermore, the PAID subfield of the User Info field for random access is set to 0. That is, an uplink user-specific PA for random access is not permitted.

[0066] In the EHT Basic Trigger frame, only one non-random access User Info field is addressed to a single STA. The random access User Info field is placed after the non-random access User Info field. STAs with uplink user-specific PAs indicated in the Common Info field are not addressed by non-random access User Info fields. Furthermore, no more than one uplink user-specific PA assigned to a single STA is indicated in the Common Info field. Advantageously, this reduces the complexity in processing the received EHT Basic Trigger frame at the STA.

[0067] The first frame 412 may be in the format of the EHT Basic Trigger frame 500. For example, at 414, the STA 406 may receive the first frame 412 in the format of the EHT Basic Trigger frame 500. The STA 406 may store an identification of the uplink user-specific PA intended for the STA 406 and user-specific resource allocation information. The identification information (e.g., PAID) may be extracted from the PAID subfield 516 of the User Info field, where the AID12 subfield value matches the AID (Association Identifier) ​​of the STA 406. The user-specific resource allocation information may also be extracted from the User Info field. The STA 406 may then transmit an EHT TB PPDU 418 to the AP 402 in response, where the EHT TB PPDU 418 is based on the stored user-specific resource allocation information.

[0068] Similarly, the STA 404 may also receive the first frame 412 in the form of the EHT Basic Trigger frame 500. The STA 404 may store the identification information of the uplink user-specific PA intended for the STA 404 and the user-specific resource allocation information. The identification information (e.g., PAID) may be extracted from the PAID subfield of the User Info field where the AID12 subfield value matches the AID of the STA 404. The user-specific resource allocation information may also be extracted from the User Info field. The STA 404 may then transmit an EHT TB PPDU 416 to the AP 402 in response, where the EHT TB PPDU 416 is based on the stored user-specific resource allocation information.

[0069] The second frame 422 may also be in the format of the EHT Basic Trigger frame 500. For example, the STA 406 may receive the second frame 422 in the format of the EHT Basic Trigger frame 500. The STA 406 may obtain the common parameters from the Common Info field 502 of the EHT Basic Trigger frame 500 and determine 414 whether the PAID stored by the STA 406 matches any PAID subfield value in the Trigger Dependent Common Info field 508 of the Common Info field 502. If there is a match, the STA 406 may prepare 424 an EHT TB PPDU 428 based on the user-specific resource allocation information stored 414 by the STA 406 and transmit the prepared EHT TB PPDU 428 to the AP 402.

[0070] Similarly, the STA 404 may receive a second frame 422 in the format of the EHT Basic Trigger frame 500. The STA 404 may obtain common parameters from the Common Info field 502 of the EHT Basic Trigger frame 500 and determine 414 whether the PAID stored by the STA 404 matches any PAID subfield value in the Trigger Dependent Common Info field 508 of the Common Info field 502. If there is a match, the STA 404 may prepare 414 an EHT TB PPDU 426 based on the user-specific resource allocation information stored by the STA 404 and transmit the prepared EHT TB PPDU 426 to the AP 402.

[0071] The second frame 422 may also be in the form of a PA Trigger frame 520 according to the first embodiment, as shown in FIG. 5C. The PA Trigger frame 520 may include (or consist of) a Frame Control field, a Duration field, an RA field, a TA field, a Common Info field, a Padding field, and an FCS field. The Common Info field may include (or consist of) a Trigger Type field, a More TF field, a CS Required field, and a Trigger Dependent Common Info field 522. The Trigger Dependent Common Info field 522 may include (or consist of) a Number of PAIDs field and a PAID Tuples field. The Number of PAIDs field indicates the number of PAID subfields included in the PAID Tuples field. Alternatively, the Trigger Dependent Common Info field 522 may include a Starting PAID field, a PAID Bitmap Size field, and a PAID Bitmap field. The PAID Bitmap Size field indicates the bit width of the PAID Bitmap field. The Starting PAID field contains the starting PAID of the PAID Bitmap field. The PAID Bitmap field, together with the Starting PAID field, indicates the PAID of the uplink user-specific PA. The PA Trigger frame 520 requests repeated transmission of the uplink user-specific PA using its PAID contained in the Trigger Dependent Common Info field 522. In the PA Trigger frame, up to one uplink user-specific PA assigned to a single STA is indicated in the Common Info field. Advantageously, this reduces the complexity in processing the received PA Trigger frame at the STA.

[0072] The PA trigger frame 520 is used only to request repeated transmission of one or more uplink user-specific PAs, such as EHT TB PPDUs 426 and 428. Only some common parameters (e.g., the More TF subfield and the CS Required subfield) are present in the Common Info field of the PA Trigger frame 520 because other common parameters do not change before the one or more uplink user-specific PAs expire and can be obtained from the first frame 412. Furthermore, user-specific resource allocation information required for the one or more uplink user-specific PAs is not included in the PA Trigger frame because it may be obtained from the first frame 412. Advantageously, this reduces the channel overhead for repeated transmission of one or more uplink user-specific PAs.

[0073] The second frame 422 may be in the form of a data or management frame 530 carrying a PA Control subfield according to the first embodiment, as shown in FIG. 5D. The data or management frame 530 may include (or consist of) a Frame Control field, a Duration / ID field, four Address fields, a Sequence Control field, a Quality of Service (QoS) field, an HT Control field, a Frame Body field, and an FCS field. The HT Control field may be a 32-bit HE variant HT Control field including (or consisting of) a VHT field (set to 1), an HE field (set to 1), a Control ID field (a value determined to indicate that the HT Control field of the data or management frame 530 includes a PA Control subfield, e.g., set to 7), and a Control Information field 532. The 26-bit Control Information field may include (or consist of) an 8-bit PAID subfield and several common parameters 534, such as a 10-bit UL Length subfield, a 5-bit DL TX Power subfield, and a 3-bit Number of HE-LTF Symbols subfield. It will be appreciated that other common parameters can be predetermined or implicitly signaled. The data or management frame 530 requests repeated transmission of the uplink user-specific PA using its PAID, which is included in the Control Information field 532. Similar to the PA Trigger frame 520, the user-specific resource allocation information needed for the uplink user-specific PA is not included in the data or management frame 530, as it may be obtained from the first frame 412. Advantageously, this reduces the channel overhead for repeated transmission of the uplink user-specific PA.

[0074] As described above, the channel overhead of the first embodiment can be further reduced. In a first frame, two or more user-specific PAs of a MU-MIMO assignment may include the same PAID, which can be signaled in a second frame to request repeated transmissions from two or more STAs participating in the MU-MIMO assignment. In one example, the first frame may be used to assign the same PAID, the same RU, and respective spatial streams to two or more user-specific PAs of a MU-MIMO assignment. In another example, two or more first frames may be used to assign the same PAID, the same RU, and respective spatial streams to two or more user-specific PAs of a MU-MIMO assignment. Alternatively, in the first frame, a group of user-specific PAs may be assigned the same PAID, which can be signaled in a second frame to request repeated transmissions for each user-specific PA in the group of user-specific PAs. However, assigning the same PAID to two or more user-specific PAs may reduce scheduling flexibility because a second frame signaling the same PAID requests repeated transmissions for all user-specific PAs with the same PAID.

[0075] In the first embodiment described above, the uplink user-specific PA may exist for a period of time after the first frame requesting the first transmission of the uplink user-specific PA is transmitted. In one example, the uplink user-specific PA may exist until the end of the current TXOP. In another example, the uplink user-specific PA may exist for a determined number of service periods or beacon intervals. In yet another example, the Common Info field of the first frame may include signaling to indicate the period of time for which the uplink user-specific PA will exist after the transmission of the first frame, the first transmission requested by the first frame. In such an example, the uplink user-specific PAs having the first transmission requested by the first frame may have the same expiration time. Alternatively, the User Info field corresponding to the uplink user-specific PA in the first frame may include signaling to indicate the period of time for which the uplink user-specific PA will exist after the transmission of the first frame. In another example, the uplink user-specific PAs having the first transmission requested by the first frame may have different expiration times.

[0076] In the first embodiment described above, the AP may transmit a first frame to update the user-specific resource allocation information of the uplink user-specific PA before it expires. If the user-specific resource allocation information of the uplink user-specific PA is updated before it expires and the intended STA fails to receive the updated information, there will be a mismatch in the information of the uplink user-specific PA between the AP and the intended STA. The AP may be able to identify such a mismatch if an EHT TB PPDU is not received in response to the transmitted first frame. When the STA receives the first frame containing complete information about the uplink user-specific PA of one of the intended STAs, the STA starts or resets the timer for the uplink user-specific PA and stores or updates information about the uplink user-specific PA. Similarly, the STA may store or update common parameters in the Common Info field through this process. Advantageously, this allows the AP to perform error recovery from the information mismatch.

[0077] In the above example, an RU allocation is addressed to one or more STAs. An RU allocation is a non-MU-MIMO allocation if it is addressed to a single STA, and a MU-MIMO allocation if it is addressed to a group of STAs. An RU allocation (i.e., a non-MU-MIMO allocation or an MU-MIMO allocation) includes one or more user-specific assignments. A non-MU-MIMO assignment includes a single user-specific assignment. A MU-MIMO assignment includes two or more user-specific assignments.

[0078] As described above, individual user-specific portions of the MU-MIMO allocation can be persistent or non-persistent. Individual user-specific PAs of the MU-MIMO allocation may have different expiration times and be independently renewable. Advantageously, compared to RU-based PA, where all user-specific portions of the MU-MIMO allocation are persistent or non-persistent, user-specific PA increases scheduling flexibility.

[0079] In the example shown in FIG. 5E, the MU-MIMO allocation includes three user-specific allocations 574 (user-specific allocation 1,...,user-specific allocation 3), where user-specific allocation 1 is a user-specific PA with PAID=2, user-specific allocation 2 is a user-specific PA with PAID=5, and user-specific allocation 3 is not a user-specific PA.

[0080] 6A shows a flowchart 600 illustrating processing of a received EHT Basic Trigger frame 500 at a STA according to a first embodiment. Processing may begin at 602. At 604, common parameters from the Common Info field 502 are obtained. At 606, it is determined whether the stored PAID matches any PAID subfield value in the Common Info field 502. If the stored PAID matches a PAID subfield value in the Common Info field 502, processing may proceed to step 608. If the stored PAID does not match any PAID subfield value in the Common Info field 502, processing may proceed to step 614. At 608, it is determined whether a timer for an uplink user-specific PA with a matching PAID is running. If a timer for an uplink user-specific PA is running, processing may proceed to step 610. Otherwise, processing may end at step 636. At 610, user-specific resource allocation information stored by the STA is extracted. At 614, the number of User Info fields is calculated. At 616, a User Info field counter is initialized to zero. At 620, it is determined whether the STA's AID matches the AID12 subfield value of the User Info field in the EHT Basic Trigger frame 500. If the STA's AID matches the AID12 subfield value, processing may proceed to step 622. If the STA's AID does not match the AID12 subfield value, processing may proceed to step 628. At 622, it is determined whether the User Info field corresponds to an uplink user-specific PA by checking the PA Flag subfield or the PAID subfield. If the User Info field does not correspond to an uplink user-specific PA, processing may proceed to step 626. If the User Info field corresponds to an uplink user-specific PA, processing may proceed to 624.In 626, to prepare an EHT TB PPDU, user-specific resource allocation information 514 is obtained from the User Info field whose AID12 subfield value matches the STA's AID. In 624, the PAID 516 and user-specific resource allocation information 514 are obtained and stored by the STA. In 628, it is determined whether the AID12 subfield value of the User Info field indicates a User Info field for which it is eligible for random access (RA). If so, processing may proceed to step 630. If not, processing may proceed to 632. In 630, a UL OFDMA-based Random Access (UORA) procedure is performed. In 632, the User Info field counter is incremented by one. In 634, it is determined whether the User Info field counter is equal to the number of User Info fields in the EHT Basic Trigger frame 500. If the User Info field counter is not equal to the number of User Info fields in the EHT Basic Trigger frame 500, the process may return to step 620 again. If the User Info field counter is equal to the number of User Info fields in the EHT Basic Trigger frame 500, the process may end at 636. It can be understood that steps 620, 628, 632, and 634 form a loop for the STA to cyclically read all user information fields present in the EHT Basic Trigger frame 500. At 612, an EHT TB PPDU is prepared based on common parameters (e.g., common parameters from the Common Info field 502) and user-specific resource allocation information (e.g., user-specific resource allocation information stored by the STA if the process is from step 610 or 624, or user-specific resource allocation information 514 obtained from the User Info field whose AID12 subfield value matches the AID of the STA if the process is from step 626). The process ends at 636.

[0081] 6B shows a flowchart 640 illustrating processing of a received PA Trigger frame 520 at a STA according to the first embodiment. Processing may begin at step 642. At 644, several common parameters are obtained from the Common Info field of the PA Trigger frame 520. At 646, it is determined whether the stored PAID matches any PAID subfield value in the Trigger Dependent Common Info field 522 of the PA Trigger frame 520. If the stored PAID matches any PAID subfield value in the Trigger Dependent Common Info field 522 of the PA Trigger frame 520, processing may proceed to step 648. If the stored PAID does not match any PAID subfield value, processing may end at step 654. At 648, it is determined whether a timer for the uplink user-specific PA with the matching PAID is running. If it is determined that the timer is running, processing may proceed to step 650. If it is determined that the timer is not running, processing may end at step 654. User-specific resource allocation information and other common parameters stored by the STA are extracted at 650. At 652, an EHT TB PPDU based on the common parameters and user-specific resource allocation information is prepared.

[0082] 6C shows a flowchart 660 illustrating processing of a received data or management frame 530 carrying a PA Control subfield at a STA that is an intended recipient of the frame 530 according to a first embodiment. Processing may begin at step 662. At 664, common parameters 534 are obtained from the PA Control subfield of the data or management frame 530. At 666, it is determined whether a timer for an uplink user-specific PA with the PAID indicated in the PA Control subfield is running. If it is determined that the timer is running, processing may proceed to step 668. If it is determined that the timer is not running, processing may end at step 672. At 668, user-specific resource allocation information stored by the STA is extracted. At 670, an EHT TB PPDU based on the common parameters 534 obtained from the PA Control subfield of the data or management frame 530 and the extracted user-specific resource allocation information is prepared.

[0083] 7A and 7B show the format of an EHT Basic Trigger frame 700 used for uplink multi-user communication between an AP and multiple STAs in an EHT WLAN according to a second embodiment. The EHT Basic Trigger frame 700 is a modification of the existing Trigger frame and may be used as the first frame 412 in FIGS. 4A and 4B. Unlike the EHT Basic Trigger frame 500, which identifies an uplink user-specific PA using the PAID of the uplink user-specific PA, the EHT Basic Trigger frame 700 identifies the uplink user-specific PA using the RU allocation information of the uplink user-specific PA as part of the identification information. In one example, the RU allocation information of the uplink user-specific PA, together with the user identification information (e.g., the user's AID) of the STA addressed by the uplink user-specific PA, is used to identify the uplink user-specific PA. In another example, the RU allocation information of the uplink user-specific PA, together with the SS allocation information (e.g., the start spatial stream) of the uplink user-specific PA, is used to identify the uplink user-specific PA. The RU allocation information includes the RU location in the frequency domain. The EHT Basic Trigger frame 700 may include a Frame Control field, a Duration field, an RA field, a TA field, a Common Info field 702, one or more User Info fields such as a User Info field 704, a Padding field, and an FCS field. The Frame Control field, the Duration field, the RA field, and the TA field may be grouped in the MAC header of the EHT Basic Trigger frame 700. The Common Info field 702, one or more User Info fields 704, and the Padding field may be grouped in the frame body of the EHT Basic Trigger frame 700.

[0084] 7A also shows the Common Info field 702 in more detail. The Common Info field 702 contains common parameters for all STAs involved in the EHT TB PPDU transmission requested by the EHT Basic Trigger frame 700. The Common Info field 702 includes (or consists of) a Trigger Type field 706, a UL Length field, a More TF field, a CS Required field, a UL BW field, a GI and LTF Type field, a MU-MIMO LTF Mode field, a Number of HE-LTF Symbols and Midamble Periodicity field, a UL STBC field, an LDPC Extra Symbol Segment field, an AP TX Power field, a Pre-FEC Padding Factor field, a PE Disambiguity field, a UL Spatial Reuse field, a Doppler field, a UL HE-SIG-A2 Reserved field, and a Trigger Dependent Common Info field 708. Unlike the Trigger Dependent Common Info field 508 of the EHT Basic Trigger frame 500, the Trigger Dependent Common Info field 708 of the EHT Basic Trigger frame 500 may include (or consist of) a Number of RU Allocations field and an RU Allocation / AID12 Tuples field. The Number of RU Allocations field indicates the number of RU Allocation / AID12 subfields in the RU Allocation / AID12 Tuples field. The EHT Basic Trigger frame 700 may then request repeated transmission of the uplink user-specific PA using the RU allocation information and user identity information of the uplink user-specific PA indicated in the Trigger Dependent Common Info field 708.Alternatively, the Trigger Dependent Common Info field 708 of the EHT Basic Trigger frame 700 may include (or consist of) a Number of RU Allocations field and an RU Allocation / SS Allocation Tuples field. The Number of RU Allocations field indicates the number of RU Allocation / SS Allocation subfields in the RU Allocation / SS Allocation Tuples field. Next, the EHT Basic Trigger frame 700 may request repeated transmission of the uplink user-specific PA using the RU allocation information and SS allocation information of the uplink user-specific PA indicated in the Trigger Dependent Common Info field 708. The Trigger Type field 706 may be assigned an arbitrary value indicating that the Trigger frame 700 is an EHT Basic Trigger frame. In various embodiments described below, the Trigger Type field 706 is assigned an arbitrary value of 8, indicating that the Trigger frame 700 is an EHT Basic Trigger frame.

[0085] 7B shows the User Info field 704 in more detail. The User Info field 704 includes an AID12 field, an RU Allocation field 716, a UL FEC Coding Type field, a UL MCS field, a UL DCM field, a SS Allocation field, a UL Target RSSI field, and a Trigger Dependent User Info field 712. Unlike the EHT Basic Trigger frame 500, the Trigger Dependent User Info field 712 may include (or consist of) a 1-bit PA Flag subfield, an MPDU MU Spacing Factor subfield, a TID Aggregation Limit subfield, and a Preferred AC subfield. The RU Allocation field 716, the UL FEC Coding Type field, the UL MCS field, the UL DCM field, the SS Allocation field, the UL Target RSSI field, the MPDU MU Spacing Factor subfield, the TID Aggregation Limit subfield, and the Preferred AC subfield constitute the user-specific resource allocation information 714 of the User Info field 704. The user-specific resource allocation information 714 may be acquired and stored by the STA for an initial or repeat uplink user-specific PA transmission, and an EHT TB PPDU based on the stored user-specific resource allocation information 714 is transmitted to the AP requesting the uplink user-specific PA transmission. Unlike the Trigger Dependent User Info field 512 of the EHT Basic Trigger frame 500, the Trigger Dependent User Info field 712 of the EHT Basic Trigger frame 700 does not include a PAID subfield.

[0086] As described above, the User Info field 704 may include a PA Flag subfield. The PA Flag subfield (e.g., 1 bit) indicates whether the User Info field 704 supports an uplink user-specific PA. A User Info field with the PA Flag subfield set to 0 indicates that the User Info field does not support an uplink user-specific PA. On the other hand, a User Info field with the PA Flag subfield set to 1 indicates that the User Info field supports an uplink user-specific PA. In this case, the RU allocation information included in the RU Allocation field of the User Info field (e.g., the RU Allocation field 716 of the User Info field 704), together with the user identification information included in the AID12 field of the User Info field (e.g., the AID12 field 718 of the User Info field 704) or the SS allocation information included in the SS Allocation field of the User Info field (e.g., the SS Allocation field 720 of the User Info field 704), identifies the uplink user-specific PA. Furthermore, the PA Flag subfield of the User Info field for random access is set to 0. That is, no uplink user-specific PA for random access is allowed.

[0087] In the EHT Basic Trigger frame, no more than one User Info field that is not for random access is addressed to a single STA. The User Info field for random access is placed after the User Info field that is not for random access. STAs that have an uplink user-specific PA announced in the Common Info field are not addressed by the User Info field that is not for random access. Furthermore, no more than one uplink user-specific PA assigned to a single STA is announced in the Common Info field. Advantageously, this reduces the complexity in processing the received EHT Basic Trigger frame at the STA.

[0088] The first frame 412 may be in the form of an EHT Basic Trigger frame 700. For example, at 414, the STA 406 may receive the first frame 412 in the form of the EHT Basic Trigger frame 700. The STA 406 may store user-specific resource allocation information of the uplink user-specific PA intended for the STA 406. Note that identification information of the uplink user-specific PA, such as RU allocation information and SS allocation information, is part of the user-specific resource allocation information of the uplink user-specific PA. The user-specific resource allocation information may be extracted from the User Info field whose AID12 subfield value matches the AID of the STA 406. The STA 406 may then transmit an EHT TB PPDU 418 to the AP 402 accordingly, where the EHT TB PPDU 418 is based on the stored user-specific resource allocation information.

[0089] Similarly, the STA 404 may also receive the first frame 412 in the form of the EHT Basic Trigger frame 700. The STA 404 may store user-specific resource allocation information of the uplink user-specific PA intended for the STA 404. Note that identification information of the uplink user-specific PA, such as RU allocation information and SS allocation information, is part of the user-specific resource allocation information of the uplink user-specific PA. The user-specific resource allocation information may be extracted from the User Info field whose AID12 subfield value matches the AID of the STA 404. The STA 404 may then transmit an EHT TB PPDU 416 to the AP 402 accordingly, where the EHT TB PPDU 416 is based on the stored user-specific resource allocation information.

[0090] The second frame 422 may also be in the form of an EHT Basic Trigger frame 700. For example, the STA 406 may receive the second frame 422 in the form of the EHT Basic Trigger frame 700. The STA 406 may obtain common parameters from the Common Info field 702 of the EHT Basic Trigger frame 700 and determine whether the RU allocation information and the user identity of the STA 406 stored by the STA 406 in 414 match any RU Allocation / AID12 field value in the Trigger Dependent Common Info field 708 of the Common Info field 702, or whether the RU allocation information and SS allocation information stored by the STA 406 in 414 match any RU Allocation / SS Allocation field value in the Trigger Dependent Common Info field 708 of the Common Info field 702. If there is a match, the STA may prepare 424 an EHT TB PPDU 428 based on the user-specific resource allocation information stored by the STA at 414 and transmit the prepared EHT TB PPDU 428 to the AP 402 .

[0091] Similarly, the STA 404 may receive the second frame 422 in the form of an EHT Basic Trigger frame 700. The STA 404 may obtain common parameters from the Common Info field 702 of the EHT Basic Trigger frame 700 and determine whether the RU allocation information and user identity information of the STA 404 stored 414 by the STA 404 match any RU Allocation / AID12 field value in the Trigger Dependent Common Info field 708 of the Common Info field 702 or any RU Allocation / AID12 field value in the Trigger Dependent Common Info field 708 of the Common Info field 702, or whether the RU allocation information and SS allocation information stored 414 by the STA 406 match any RU Allocation / SS Allocation field value in the Trigger Dependent Common Info field 708 of the Common Info field 702. If there is a match, the STA may prepare an EHT TB PPDU 426 based on the user-specific resource allocation information stored by the STA at 414 and transmit the prepared EHT TB PPDU 426 to the AP 402 .

[0092] The second frame 422 may also be in the form of a PA Trigger frame 720 according to a second embodiment, as shown in Figure 7C. The PA Trigger frame 720 may include (or consist of) a Frame Control field, a Duration field, an RA field, a TA field, a Common Info field, a Padding field, and an FCS field. The Common Info field may include (or consist of) a Trigger Type field, a More TF field, a CS Required field, and a Trigger Dependent Common Info field 722. The Trigger Dependent Common Info field 722 may include (or consist of) a Number of RU Allocations field and an RU Allocation / AID12 Tuples field. The Number of RU Allocations field indicates the number of RU Allocation / AID12 subfields in the RU Allocation / AID12 Tuples field. Unlike PA Trigger frame 520, which requests repeated transmission of an uplink user-specific PA using its PAID included in Trigger Dependent Common Info field 522, PA Trigger frame 720 may then request repeated transmission of an uplink user-specific PA using its RU allocation information and user identity information included in Trigger Dependent Common Info field 722. Alternatively, Trigger Dependent Common Info field 722 may include (or consist of) a Number of RU Allocations field and an RU Allocation / SS Allocation Tuples field.The Number of RU Allocations field indicates the number of RU Allocation / SS Allocation subfields in the RU Allocation / SS Allocation Tuples field. The PA Trigger frame 720 may then request repeated transmission of the uplink user-specific PA using the RU allocation information and SS allocation information of the uplink user-specific PA indicated in the Trigger Dependent Common Info field 722. In the PA Trigger frame, one or less uplink user-specific PAs assigned to a single STA are indicated in the Common Info field. Advantageously, this reduces the complexity in processing the received PA Trigger frame at the STA.

[0093] The PA Trigger frame 720 is used only to request repeated transmission of one or more PAs, such as EHT TB PPDUs 426 and 428. Only some common parameters are present in the Common Info field of the PA Trigger frame 720, while other common parameters do not change before one or more PAs expire and can be obtained from the first frame 412. Furthermore, except for the identification information of one or more PAs, other user-specific resource allocation information required for one or more PAs may be obtained from the first frame 412 and is therefore not included in the PA Trigger frame. Advantageously, this reduces the channel overhead for repeated transmission of one or more uplink user-specific PAs.

[0094] The second frame 422 may also be in the form of a data or management frame 730 carrying a PA Control subfield according to a second embodiment, as shown in FIG. 7D. The data or management frame 730 may include (or consist of) a Frame Control field, a Duration / ID field, four Address fields, a Sequence Control field, a QoS Control field, an HT Control field, a Frame Body field, and an FCS field. The HT Control field may be a 32-bit HE variant HT Control field that includes (or consists of) a VHT field (set to 1), an HE field (set to 1), a Control ID field (set to a determined value, e.g., 7, to signal that the HT Control field of the data or management frame 730 includes a PA Control subfield), and a Control Information field. The 26-bit Control Information field may include (or consist of) an 8-bit RU Allocation subfield and several common parameters 734, such as a 10-bit UL Length subfield, a 5-bit DL TX Power subfield, and a 3-bit Number of HE-LTF Symbols subfield. It may be understood that other common parameters may be predetermined or may be implicitly signaled. Unlike data or management frame 530, which requests repeated transmission of an uplink user-specific PA using its PAID contained in Control Information field 532, data or management frame 730 may request repeated transmission of an uplink user-specific PA using its RU allocation information contained in Control Information field 732 and the user identity (e.g., MAC address) of the intended STA contained in one of the four Address fields.Similar to the PA Trigger frame 720, other user-specific resource allocation information needed for the uplink user-specific PA may be obtained from the first frame 412 and is therefore not included in the data or management frame 530. Advantageously, this reduces the channel overhead for repeated transmissions of the uplink user-specific PA.

[0095] In the second embodiment as described above, the uplink user-specific PA may exist for a period of time after the first frame requesting the first transmission of the uplink user-specific PA is transmitted. In one example, the uplink user-specific PA may exist until the end of the current TXOP. In another example, the uplink user-specific PA may exist for a determined number of service periods or beacon intervals. In yet another example, the Common Info field of the first frame may include signaling to indicate the period of time during which the uplink user-specific PA will exist after the first frame is transmitted, where the first transmission requested by the first frame is transmitted. In such an example, the first transmission requested by the first frame is an uplink user-specific PA with the same expiration time. Alternatively, the User Info field corresponding to the uplink user-specific PA in the first frame may include signaling to indicate the period of time during which the uplink user-specific PA will exist after the first frame is transmitted. In another example, the first transmission requested by the first frame is an uplink user-specific PA with a different expiration time.

[0096] In the second embodiment as described above, the AP may transmit a first frame to update user-specific resource allocation information, excluding the identification information (e.g., RU allocation information and SS allocation information) of the uplink user-specific PA, before it expires. If the user-specific resource allocation information of the uplink user-specific PA is updated before it expires and the intended STA fails to receive the updated information, there will be a mismatch between the AP and the intended STA regarding the information of the uplink user-specific PA. The AP may be able to identify such a mismatch if an EHT TB PPDU is not received in response to the transmitted first frame. When the STA receives the first frame containing complete information regarding the uplink user-specific PA for which it is the intended STA, it starts or resets the timer for the uplink user-specific PA and stores or updates information regarding the uplink user-specific PA. Similarly, the STA may also store or update common parameters in the Common Info field through this process. Advantageously, this allows the AP to perform error recovery from the information mismatch.

[0097] 8A shows a flowchart 800 illustrating the processing of an EHT Basic Trigger frame 700 received at a STA according to the second embodiment. The process may start at 802. At 804, common parameters from the Common Info field 702 are obtained. At 806, it is determined whether repeated transmission of the intended uplink user-specific PA for the STA is requested. This can be done by checking whether the STA's stored RU allocation information and user identity information match any RU Allocation / AID12 subfield value in the Common Info field 702, or whether the stored RU allocation information and SS allocation information match any RU Allocation / SS Allocation subfield value in the Common Info field 702. If repeated transmission of the intended uplink user-specific PA for the STA is requested, the process may proceed to step 808. Otherwise, the process may proceed to step 814. At 808, it is determined whether a timer for the uplink user-specific PA is running. If the timer for uplink user-specific PA is running, processing may proceed to step 810. Otherwise, processing ends at step 836. At 810, user-specific resource allocation information stored by the STA is extracted. At 814, the number of User Info fields is calculated. At 816, a User Info field counter is initialized to zero. At 820, it is determined whether the AID of the STA matches the AID12 subfield value of the User Info field in the EHT Basic Trigger frame 700. If the AID of the STA matches the AID12 subfield value, processing may proceed to step 822. If the AID of the STA does not match the AID12 subfield value, processing may proceed to step 828. At 822, it is determined whether the PA Flag subfield is set to 1.If the PA Flag subfield is not set to 1, i.e., the User Info field does not correspond to an uplink user-specific PA, processing may proceed to step 826. If the PA Flag subfield is set to 1, i.e., the User Info field corresponds to an uplink user-specific PA, processing may proceed to 824. At 826, user-specific resource allocation information 714 is obtained from the User Info field. At 824, the user-specific resource allocation information 714 is obtained from the User Info field and stored by the STA. At 828, it is determined whether the AID12 subfield value of the User Info field indicates a User Info field for which it is eligible. If so, processing may proceed to step 830. If not, processing may proceed to 832. At 830, a UORA procedure is performed. At 832, the User Info field counter is incremented by 1. At 834, it is determined whether the User Info field counter is equal to the number of User Info fields in the EHT Basic Trigger frame 700. If the User Info field counter is not equal to the number of User Info fields in the EHT Basic Trigger frame 700, processing may again proceed to step 820. If the User Info field counter is equal to the number of User Info fields in the EHT Basic Trigger frame 700, processing may end at 836. It may be understood that steps 820, 828, 832, and 834 form a loop for the STA to cycle through and read all User Info fields present in the EHT Basic Trigger frame 700.At 812, an EHT TB PPDU is prepared based on the common parameters (e.g., common parameters from the Common Info field 702) and user-specific resource allocation information (e.g., user-specific resource allocation information stored by the STA if the process is from step 810 or 824, or user-specific resource allocation information obtained from the User Info field 714 if the process is from step 826). At 836, the process ends.

[0098] 8B shows a flowchart 840 illustrating processing of a PA Trigger frame 720 received at a STA according to the second embodiment. The process may start at step 842. At 844, some common parameters are obtained from the Common Info field of the PA Trigger frame 720. At 846, it is determined whether repeated transmission of the intended uplink user-specific PA for the STA is requested. This can be done by checking whether the stored RU allocation information and the STA's user identity information match any RU Allocation / AID12 subfield value in the Trigger Dependent Common Info field 722, or whether the stored RU allocation information and SS allocation information match any RU Allocation / SS Allocation subfield value in the Trigger Dependent Common Info field 722. If repeated transmission of the intended uplink user-specific PA for the STA is requested, the process may proceed to step 848. Otherwise, the process may end at step 854. At 848, it is determined whether a timer for the uplink user-specific PA is running. If it is determined that the timer is running, the process may proceed to step 850. If it is determined that the timer is not running, the process may end at step 854. At 850, the stored user-specific resource allocation information and other common parameters are extracted. At 852, an EHT TB PPDU based on the common parameters and the user-specific resource allocation information is prepared. At 854, the process ends.

[0099] 8C shows a flowchart 860 illustrating processing of a received data or management frame 730 carrying a PA Control subfield at a STA that is an intended recipient of the frame 730 according to a second embodiment. Processing may start at step 862. At 864, common parameters 734 are obtained from the PA Control subfield of the data or management frame 730. At 866, it is determined whether a timer for uplink user-specific PA with RU allocation information indicated in the PA Control subfield is running. If it is determined that the timer is running, processing may proceed to step 868. If it is determined that the timer is not running, processing may end at step 872. At 868, user-specific resource allocation information stored by the STA is extracted. At 870, an EHT TB PPDU based on the common parameters 734 obtained from the PA Control subfield of the data or management frame 730 and the extracted user-specific resource allocation information is prepared. Processing ends at 872.

[0100] FIG. 9A shows a flowchart 900 illustrating communication between multiple STAs (904, 906) with uplink user-specific PAs and an AP 902 via a TXOP in accordance with various embodiments. A contention-based channel access procedure, e.g., an EDCA procedure, is indicated by block 908, and a SIFS 910 is shown. The AP 902 may generate a first frame 912. A complete description for the uplink user-specific PA is signaled in the first frame 912. The complete PA information may include identification information and user-specific resource allocation information. In one embodiment, the identification information may be the PAID of the uplink user-specific PA. In another embodiment, the identification information may be RU allocation information and user identification information for the uplink user-specific PA. In yet another embodiment, the identification information may be RU allocation information and SS allocation information for the uplink user-specific PA. In various embodiments, the identification information, along with the user-specific resource allocation information, is included in the frame body of the frame to identify the uplink user-specific PA. 4A, the first frame 912 does not request the initial transmission of an uplink user-specific PA. The AP 902 may transmit the generated first frame 912 to the STAs 404 and 906.

[0101] At 914, the STA 906 may receive the first frame 912 and store complete information about the uplink user-specific PA (i.e., the identification information of the uplink user-specific PA intended for the STA 906 and the user-specific resource allocation information). Unlike the embodiment shown in FIG. 4A, the STA 906 does not transmit an EHT TB PPDU to the AP 902 because an initial transmission is not requested by the first frame 912. The STA 904 may also receive and store complete information about the uplink user-specific PA (i.e., the identification information of the uplink user-specific PA intended for the STA 904 and the user-specific resource allocation information).

[0102] Thereafter, the AP 902 may request transmission of an uplink user-specific PA for STA 904 and transmission of an uplink user-specific PA for STA 906 by transmitting a second frame 922. The second frame 922 may carry identification information of the uplink user-specific PA for STA 904 to request the initial or repeat transmission of the uplink user-specific PA for STA 904 and identification information of the uplink user-specific PA for STA 906 to request the initial or repeat transmission of the uplink user-specific PA for STA 906. In various embodiments, the identification information for the uplink user-specific PA is included in the frame body of the second frame 922 to request transmission of the uplink user-specific PA, and the frame does not have user-specific resource allocation information for the uplink user-specific PA. In various embodiments, the identification information is included in the MAC header of the second frame 922 to request transmission of the uplink user-specific PA, and the frame does not have user-specific resource allocation information for the uplink user-specific PA. Advantageously, the channel overhead for transmission of the uplink user-specific PA may be reduced since the second frame is free of user-specific resource allocation information for the uplink user-specific PA.

[0103] At 924, the STA 406 may prepare an EHT TB PPDU 918 based on the stored user-specific resource allocation information for the uplink user-specific PA and transmit the EHT TB PPDU 918 to the AP 902. The EHT TB PPDU 918 is an uplink user-specific PA transmission for the STA 906. The STA 904 may also prepare an EHT TB PPDU 916 based on the stored user-specific resource allocation information for the uplink user-specific PA and transmit the EHT TB PPDU 916 to the AP 902. The EHT TB PPDU 916 is an uplink user-specific PA transmission for the STA 904. The EHT TB PPDUs 916 and 918 may have the same format as the EHT TB PPDU 212 shown in FIG. 2B . The AP 902 may receive the EHT TB PPDU 916 and 918 transmissions and transmit a Multi-STA BlockAck frame 920 to the STAs 904 and 906. As shown in FIG. 9A, the initial or repeated transmission of the uplink user-specific PA may occur within the same TXOP as the first frame transmission. As shown in FIG. 9B, the initial or repeated transmission may also occur in a different TXOP from the first frame transmission. That is, as an example, the uplink user-specific PA may exist until the end of the current TXOP. As another example, the uplink user-specific PA may exist for a determined number of service periods or beacon intervals. In FIG. 9B, the second frame 922 is transmitted by the AP 902 in a different TXOP from the first frame 912, and therefore, the transmissions requested by the second frame 922 (e.g., uplink user-specific PA transmissions of EHT TB PPDUs 916 and 918) also occur in a different TXOP from the first frame 912. It can be understood that the transmission of the second frame 922 occurs within a period during which the uplink user-specific PA for the STAs 904 and 906 exists.

[0104] FIG. 10A shows the format of a PA Announcement frame 1000 used for uplink or downlink multi-user communication between an AP and multiple STAs in an EHT WLAN according to a third embodiment. The PA Announcement frame 1000 contains complete information about one or more PAs and may be used as the first frame 912 in FIGS. 9A and 9B. The PA Announcement frame 1000 identifies the uplink user-specific PA using the PAID of the uplink user-specific PA. The PA Announcement frame 1000 may include a Frame Control field, a Duration field, an RA field, a TA field, a Common Info field, one or more User Info fields such as a User Info field 1004, a Padding field, and an FCS field. The Frame Control field, the Duration field, the RA field, and the TA field may be grouped in the MAC header of the PA Announcement frame 1000. The Common Info field, one or more User Info fields 1004, and the Padding field may be grouped in the frame body of the PA Announcement frame 1000.

[0105] 10A also shows the User Info field 1004 in more detail. The User Info field 1004 includes a Direction field 1006, an AID12 field, a PAID field 1002, an RU Allocation field, a UL FEC Coding Type field, a UL MCS field, a UL DCM field, a SS Allocation field, a UL Target RSSI field, an MPDU MU Spacing Factor subfield, a TID Aggregation Limit subfield, and a Preferred AC subfield. The RU Allocation field, the UL FEC Coding Type field, the UL MCS field, the UL DCM field, the SS Allocation field, the UL Target RSSI field, the MPDU MU Spacing Factor subfield, the TID Aggregation Limit subfield, and the Preferred AC subfield constitute user-specific resource allocation information 1008 of the User Info field 1004.

[0106] As described above, the User Info field 1004 may include a Direction field 1006. The Direction field 1006 indicates whether the User Info field 1004 corresponds to an uplink user-specific PA or a downlink user-specific PA. For example, a Direction field value of 1 indicates a downlink user-specific PA, and a Direction field value of 0 indicates an uplink user-specific PA. In this embodiment, the Direction field 1006 is set to 0 to indicate that the User Info field 1004 corresponds to an uplink user-specific PA. The User Info field 1004 may also include a PAID field 1002 that indicates the PAID of the uplink user-specific PA corresponding to the User Info field 1004.

[0107] The first frame 912 may be in the form of a PA Announcement frame 1000. For example, at 914, the STA 906 may receive the first frame 912 in the form of the PA Announcement frame 1000. The STA 906 may store an identification of the uplink user-specific PA intended for the STA 906 and user-specific resource allocation information. The identification information (e.g., PAID) may be extracted from the PAID subfield 1002 of the User Info field where the AID12 subfield value matches the AID of the STA 906. The user-specific resource allocation information may be extracted from the User Info field.

[0108] Similarly, the STA 904 may receive the first frame 912 in the form of a PA Announcement frame 1000. The STA 904 may store the identification information of the uplink user-specific PA intended for the STA 904 and the user-specific resource allocation information. The identification information (e.g., PAID) may be extracted from the PAID subfield 1002 of the User Info field where the AID12 subfield value matches the AID of the STA 904. The user-specific resource allocation information may also be extracted from the User Info field.

[0109] 10B shows the format of an EHT Basic Trigger frame 1010 used for uplink multi-user communication between an AP and multiple STAs in an EHT WLAN according to a third embodiment. The EHT Basic Trigger frame 1010 is a modification of the existing Trigger frame and may be used as the second frame 922 in FIGS. 9A and 9B. The EHT Basic Trigger frame 1010 identifies the uplink user-specific PA using the PAID of the uplink user-specific PA. The EHT Basic Trigger frame 1010 may include a Frame Control field, a Duration field, an RA field, a TA field, a Common Info field, one or more User Info fields such as a User Info field 1016, a Padding field, and an FCS field. The Frame Control field, the Duration field, the RA field, and the TA field may be grouped in the MAC header of the EHT Basic Trigger frame 1010. The Common Info field, one or more User Info fields 1016, and the Padding field may be grouped in the frame body of the EHT Basic Trigger frame 1010. The Common Info field (including all subfields of the Common Info field) of the EHT Basic Trigger frame 1010 is the same as the Common Info field 502 (including all subfields of the Common Info field 502) of the EHT Basic Trigger frame 500, as shown in Figure 5A. The User Info field 1016 may include (or consist of) an AID12 field, an RU Allocation field, a UL FEC Coding Type field, a UL MCS field, a UL DCM field, an SS Allocation field, a UL Target RSSI field, and a Trigger Dependent User Info field 1012.The Trigger Dependent User Info field 1012 may include (or consist of) an MPDU MU Spacing Factor subfield, a TID Aggregation Limit subfield, and a Preferred AC subfield. The RU Allocation field, the UL FEC Coding Type field, the UL MCS field, the UL DCM field, the SS Allocation field, the UL Target RSSI field, the MPDU MU Spacing Factor subfield, the TID Aggregation Limit subfield, and the Preferred AC subfield constitute the user-specific resource allocation information 1014 of the User Info field 1016.

[0110] In the EHT Basic Trigger frame, no more than one User Info field that is not for random access is addressed to a single STA. The User Info field for random access is placed after the User Info field that is not for random access. STAs with uplink user-specific PAs indicated in the Common Info field are not addressed by the User Info field that is not for random access. Furthermore, no more than one uplink user-specific PA assigned to a single STA is announced in the Common Info field. Advantageously, this reduces the complexity in processing the EHT Basic Trigger frame received at the STA.

[0111] The second frame 922 may also be in the form of an EHT Basic Trigger frame 1010. For example, the STA 906 may receive the second frame 922 in the form of the EHT Basic Trigger frame 1010. The STA 906 may obtain common parameters from the Common Info field of the EHT Basic Trigger frame 1010 and determine whether the PAID stored by the STA 906 at 914 matches any PAID subfield value in the Trigger Dependent Common Info field. If so, the STA 906 may prepare 924 an EHT TB PPDU 918 based on the user-specific resource allocation information stored by the STA 906 at 914 and transmit the prepared EHT TB PPDU 918 to the AP 902.

[0112] Similarly, the STA 904 may receive a second frame 922 in the form of an EHT Basic Trigger frame 1010. The STA 904 may obtain common parameters from the Common Info field of the EHT Basic Trigger frame 1010 and determine whether the PAID stored by the STA 904 matches any PAID subfield value in the Trigger Dependent Common Info field. If so, the STA 904 may prepare an EHT TB PPDU 916 based on the user-specific resource allocation information stored by the STA 904 and transmit the prepared EHT TB PPDU 916 to the AP 902.

[0113] The second frame 922 may be in the form of a PA Trigger frame 520 according to a third embodiment, as shown in FIG. 5C. The PA Trigger frame 520 is used only to request the transmission of one or more PAs, such as EHT TB PPDUs 916 and 918. Only some common parameters are present in the Common Info field of the PA Trigger frame 520; other common parameters do not change until one or more PAs expire and can be obtained from the initial frame 912. Furthermore, user-specific resource allocation information needed for one or more PAs may be obtained from the initial frame 912 and is therefore not included in the PA Trigger frame. Advantageously, this reduces the channel overhead for transmission of uplink user-specific PAs.

[0114] The second frame 922 may be in the form of a data or management frame 530 carrying a PA Control subfield according to a third embodiment, as shown in FIG. 5D. The data or management frame 530 requests the transmission of an uplink user-specific PA using its PAID indicated in a Control Information field 532. As with the PA Trigger frame 520, the user-specific resource allocation information required for the uplink user-specific PA may be obtained from the first frame 912 and is therefore not included in the data or management frame 530. Advantageously, this reduces the channel overhead for the transmission of the uplink user-specific PA.

[0115] As described above, according to the third embodiment, channel overhead can be further reduced. In a first frame, two or more user-specific PAs of an uplink MU-MIMO assignment may include the same PAID, which can be signaled in a second frame to request transmissions from two or more STAs participating in the uplink MU-MIMO assignment. In one example, the first frame may be used to assign the same PAID, the same RU, and respective spatial streams to two or more user-specific PAs of an uplink MU-MIMO assignment. In another example, two or more first frames may be used to assign the same PAID, the same RU, and respective spatial streams to two or more user-specific PAs of an uplink MU-MIMO assignment. Alternatively, the first frame may assign the same PAID to a group of user-specific PAs, which can be signaled in a second frame to request transmissions from each user-specific PA of the group of user-specific PAs.

[0116] In the third embodiment described above, the uplink user-specific PA may exist for a period of time after the first frame announcing the uplink user-specific PA is transmitted. In one example, the uplink user-specific PA may exist until the end of the current TXOP. In another example, the uplink user-specific PA may exist for a determined number of service periods or beacon intervals. In yet another example, the Common Info field in the first frame may include signaling to indicate the period of time the uplink user-specific PA announced by the first frame will exist after the first frame is transmitted. In such an example, the uplink user-specific PAs announced by the first frame have the same expiration time. Alternatively, the User Info field corresponding to the uplink user-specific PA in the first frame may include signaling to indicate the period of time the uplink user-specific PA will exist after the first frame is transmitted. In another example, the uplink user-specific PAs announced by the first frame may have different expiration times.

[0117] 11 shows a flowchart 1100 illustrating processing of an EHT Basic Trigger frame 1010 received at a STA according to a third embodiment. Processing may start at 1102. At 1104, common parameters are obtained from the Common Info field of the EHT Basic Trigger frame 1010. At 1106, it is determined whether a stored PAID matches any PAID subfield value in the Common Info field. If the stored PAID matches any PAID subfield value in the Common Info field, processing may proceed to step 1108. If the stored PAID does not match any PAID subfield value in the Common Info field, processing may proceed to step 1114. At 1108, it is determined whether a timer for an uplink user-specific PA with a matching PAID is running. If a timer for an uplink user-specific PA is running, processing may proceed to step 1110. Otherwise, processing may end at step 1130. At 1110, user-specific resource allocation information stored by the STA is extracted. At 1114, the number of User Info fields present in the EHT Basic Trigger frame 1010 is calculated. At 1116, a User Info field counter is initialized to zero. At 1118, it is determined whether the STA's AID matches the AID12 subfield value of the User Info field of the EHT Basic Trigger frame 1010. If the STA's AID matches the AID12 subfield value, processing may proceed to step 1120. If the STA's AID does not match the AID12 subfield value, processing may proceed to step 1122. At 1120, user-specific resource allocation information is obtained from the User Info field to prepare an EHT TB PPDU. At 1122, it is determined whether the AID12 subfield value of the User Info field indicates the User Info field of an RA for which it is eligible. If so, processing may proceed to step 1124.If not, processing may proceed to 1126. At 1124, a UORA procedure is performed. At 1126, the User Info field counter is incremented by one. At 1128, it is determined whether the User Info field counter is equal to the number of User Info fields in the EHT Basic Trigger frame 1010. If the User Info field counter is not equal to the number of User Info fields in the EHT Basic Trigger frame 1010, processing may proceed again to step 1118. If the User Info field counter is equal to the number of User Info fields in the EHT Basic Trigger frame 1010, processing may end at 1130. It may be understood that steps 1118, 1122, 1126, and 1128 form a loop for the STA to cycle through and read all User Info fields present in the EHT Basic Trigger frame 1010. At 1112, an EHT TB PPDU is prepared based on the common parameters (e.g., common parameters from the Common Info field of the EHT Basic Trigger frame 1010) and user-specific resource allocation information (e.g., user-specific resource allocation information stored by the STA if processing is from step 1110, or user-specific resource allocation information obtained from the User Info field 1014 if processing is from step 1120). At 1130, processing ends.

[0118] The processing of a received PA Trigger frame 520 at a STA according to the third embodiment is also shown in flow chart 640 of FIG. 6B.

[0119] The processing of a received data or management frame 530 carrying a PA Control subfield at a STA that is the intended recipient of the frame 530 according to the third embodiment is also shown in flow chart 660 of FIG. 6C.

[0120] In the third embodiment as described above, the AP may transmit a first frame to update the user-specific resource allocation information of the uplink user-specific PA before it expires. If the user-specific resource allocation information of the uplink user-specific PA is updated before it expires and the intended STA fails to receive the updated information, there will be a mismatch between the AP and the intended STA regarding the information of the uplink user-specific PA. The AP can identify such a mismatch if an EHT TB PPDU is not received in response to the transmitted second frame. When the STA receives the first frame containing information about the uplink user-specific PA of which it is one of the intended recipients, it starts or resets the timer for the uplink user-specific PA and stores or updates the information about the uplink user-specific PA. Similarly, the STA may also store or update common parameters in the Common Info field through this process. Advantageously, this allows the AP to perform error recovery from the information mismatch.

[0121] FIG. 12 shows the format of a PA Announcement frame 1200 used for uplink or downlink multi-user communication between an AP and multiple STAs in an EHT WLAN according to a fourth embodiment. The PA Announcement frame 1200 includes complete information about one or more PAs and may be used as the first frame 912 in FIGS. 9A and 9B. The PA Announcement frame 1200 may identify the uplink user-specific PA using the RU allocation information of the uplink user-specific PA and the user identity information of the STA addressed by the uplink user-specific PA. Alternatively, the PA Announcement frame 1200 may identify the uplink user-specific PA using the RU allocation information and SS allocation information (e.g., start spatial stream) of the uplink user-specific PA. The PA Announcement frame 1200 may include a Frame Control field, a Duration field, an RA field, a TA field, a Common Info field, one or more User Info fields such as a User Info field 1204, a Padding field, and an FCS field. The Frame Control field, Duration field, RA field, and TA field may be grouped in the MAC header of the PA Announcement frame 1200. The Common Info field, one or more User Info fields 1204, and Padding field may be grouped in the frame body of the PA Announcement frame 1200.

[0122] 12 also shows the User Info field 1204 in more detail. The User Info field 1204 includes the Direction field 1026, the AID12 field, the RU Allocation field 1202, the UL FEC Coding Type field, the UL MCS field, the UL DCM field, the SS Allocation field, the UL Target RSSI field, the MPDU MU Spacing Factor subfield, the TID Aggregation Limit subfield, and the Preferred AC subfield. The RU Allocation field, the UL FEC Coding Type field, the UL MCS field, the UL DCM field, the SS Allocation field, the UL Target RSSI field, the MPDU MU Spacing Factor subfield, the TID Aggregation Limit subfield, and the Preferred AC subfield constitute the user-specific resource allocation information 1208 of the User Info field 1204.

[0123] As described above, the User Info field 1204 may include a Direction field 1206. The Direction field 1206 indicates whether the User Info field 1204 corresponds to an uplink user-specific PA or a downlink user-specific PA. For example, a Direction field value of 1 indicates a downlink user-specific PA, and a Direction field value of 0 indicates an uplink user-specific PA. In this embodiment, the Direction field 1206 is set to 0 to indicate that the User Info field corresponds to an uplink user-specific PA. The User Info field 1204 may also include an RU Allocation field 1202 indicating RU allocation information, an SS Allocation field 1212 indicating SS allocation information, and an AID12 field 1214 indicating user identification information. Unlike the PA Announcement frame 1000, which uses the PAID indicated in the PAID field 1002 to identify the uplink user-specific PA corresponding to the User Info field 1004, the PA Announcement frame 1200 may use the RU allocation information indicated in the RU Allocation field 1202 and the user identification information indicated in the AID12 field 1214 to identify the uplink user-specific PA corresponding to the User Info field 1204. Alternatively, the PA Announcement frame 1200 may use the RU allocation information indicated in the RU Allocation field 1202 and the SS allocation information indicated in the SS Allocation field 1212 to identify the uplink user-specific PA corresponding to the User Info field 1204.

[0124] The first frame 912 may be in the form of a PA Announcement frame 1200. For example, at 914, the STA 906 may receive the first frame 912 in the form of the PA Announcement frame 1200. The STA 906 may store user-specific resource allocation information of the uplink user-specific PA intended for the STA 906. Note that identification information of the uplink user-specific PA, such as RU allocation information and SS allocation information, is part of the user-specific resource allocation information of the uplink user-specific PA. The user-specific resource allocation information may be extracted from the User Info field whose AID12 subfield value matches the AID of the STA 906.

[0125] Similarly, the STA 904 may also receive the first frame 912 in the form of a PA Announcement frame 1200. The STA 904 may store user-specific resource allocation information of the uplink user-specific PA intended for the STA 904. Note that identification information of the uplink user-specific PA, such as RU allocation information and SS allocation information, is part of the user-specific resource allocation information of the uplink user-specific PA. The user-specific resource allocation information may be extracted from the User Info field whose AID12 subfield value matches the AID of the STA 904.

[0126] The second frame 922 may be in the form of an EHT Basic Trigger frame used for uplink multi-user communication between an AP and multiple STAs in an EHT WLAN according to a fourth embodiment. The EHT Basic Trigger frame according to the fourth embodiment is a modification of an existing Trigger frame and may be used as the second frame 922 in FIGS. 9A and 9B . The EHT Basic Trigger frame according to the fourth embodiment may identify an uplink user-specific PA using RU allocation information and user identification information. Alternatively, the EHT Basic Trigger frame according to the fourth embodiment may identify an uplink user-specific PA using RU allocation information and SS allocation information. The EHT Basic Trigger frame according to the fourth embodiment may include a Frame Control field, a Duration field, an RA field, a TA field, a Common Info field, one or more User Info fields, a Padding field, and an FCS field. The Frame Control field, the Duration field, the RA field, and the TA field may be grouped in the MAC header of the EHT Basic Trigger frame. The Common Info field, one or more User Info fields, and Padding field may be grouped in the frame body of the EHT Basic Trigger frame according to the fourth embodiment. The Common Info field (including all subfields of the Common Info field) of the EHT Basic Trigger frame according to the fourth embodiment is the same as the Common Info field 702 (including all subfields of the Common Info field 702) of the EHT Basic Trigger frame 700, as shown in Figure 7A.The User Info field (including all subfields of the User Info field) of the EHT Basic Trigger frame according to the fourth embodiment is identical to the User Info field 1016 (including all subfields of the User Info field 1016) of the EHT Basic Trigger frame 1010, as shown in FIG. 10B.

[0127] For example, the STA 906 may receive a second frame 922 in the form of an EHT Basic Trigger frame according to the fourth embodiment. The STA 906 may obtain common parameters from the Common Info field of the EHT Basic Trigger frame and determine whether the RU allocation information and user identification information stored by the STA 906 at 914 match any RU Allocation / AID12 subfield value in the Trigger Dependent Common Info field of the Common Info field, or whether the RU allocation information and SS allocation information stored by the STA 906 at 914 match any RU Allocation / SS Allocation subfield value in the Trigger Dependent Common Info field of the Common Info field. If so, the STA 906 may prepare an EHT TB PPDU 918 at 924 based on the user-specific resource allocation information stored by the STA 906 at 914 and transmit the prepared EHT TB PPDU 918 to the AP 902.

[0128] Similarly, the STA 904 may receive a second frame 922 in the form of an EHT Basic Trigger frame according to the fourth embodiment. The STA 904 may obtain common parameters from the Common Info field of the EHT Basic Trigger frame and determine whether the RU allocation information and user identification information stored by the STA 904 at 914 match any RU Allocation / AID12 subfield value in the Trigger Dependent Common Info field of the Common Info field, or whether the RU allocation information and SS allocation information stored by the STA 904 at 914 match any RU Allocation / SS Allocation subfield value in the Trigger Dependent Common Info field of the Common Info field. If so, the STA 904 may prepare an EHT TB PPDU 916 based on the user-specific resource allocation information stored by the STA 904 at 914 and transmit the prepared EHT TB PPDU 916 to the AP 902.

[0129] In the EHT Basic Trigger frame, no more than one non-random access User Info field is addressed to a single STA. The random access User Info field is placed after the non-random access User Info field. STAs with uplink user-specific PAs indicated in the Common Info field are not addressed by the non-random access User Info field. Furthermore, no more than one uplink user-specific PA assigned to a single STA is announced in the Common Info field. Advantageously, this reduces the complexity in processing the EHT Basic Trigger frame received at the STA.

[0130] The second frame 922 may also be in the form of a PA Trigger frame 720 according to a second embodiment, as shown in FIG. 7C.

[0131] The PA Trigger frame 720 is used only to request the transmission of one or more uplink user-specific PAs, such as EHT TB PPDUs 916 and 918. Only some common parameters are present in the Common Info field of the PA Trigger frame 720, while other common parameters do not change before one or more PAs expire and can be obtained from the first frame 912. Furthermore, user-specific resource allocation information needed for one or more PAs may be obtained from the first frame 912 and is therefore not included in the PA Trigger frame, except for identification information of the one or more PAs. Advantageously, this reduces the channel overhead for the transmission of one or more uplink user-specific PAs.

[0132] The second frame 922 may also be in the form of a data or management frame 730 carrying a PA Control subfield according to a fourth embodiment, as shown in FIG. 7D. The data or management frame 730 requests transmission of an uplink user-specific PA using its RU allocation information contained in the Control Info field 732 and user identification information (e.g., MAC address) contained in one of the four Address fields. Other user-specific resource allocation information required for the uplink user-specific PA may be obtained from the initial frame 912 and is therefore not included in the data or management frame 730. Advantageously, this reduces the channel overhead for transmission of the uplink user-specific PA.

[0133] In the fourth embodiment as described above, the uplink user-specific PA may exist for a period of time after the first frame announcing the uplink user-specific PA is transmitted. In one example, the uplink user-specific PA may exist until the end of the current TXOP. In another example, the uplink user-specific PA may exist for a determined number of service periods or beacon intervals. In yet another example, the Common Info field of the first frame may include signaling to indicate the period of time the uplink user-specific PA announced by the first frame will exist after the first frame is transmitted. In such an example, the uplink user-specific PAs announced by the first frame have the same expiration time. Alternatively, the User Info field corresponding to the uplink user-specific PA in the first frame may include signaling to indicate the period of time the uplink user-specific PA will exist after the first frame is transmitted. In another example, the uplink user-specific PAs announced by the first frame may have different expiration times.

[0134] 13 shows a flowchart 1300 illustrating processing of a received EHT Basic Trigger frame in a STA according to a fourth embodiment. Processing may start at 1302. At 1304, common parameters are obtained from the Common Info field of the EHT Basic Trigger frame. At 1306, it is determined whether the STA is requested to transmit an intended uplink user-specific PA. This can be done by checking whether the stored RU allocation information and user identity information match any RU Allocation / AID12 subfield value in the Common Info field, or whether the stored RU allocation information and SS allocation information match any RU Allocation / SS Allocation subfield value in the Common Info field. If the STA is requested to transmit an intended uplink user-specific PA, processing may proceed to step 1308. Otherwise, processing may proceed to step 1314. At 1308, it is determined whether a timer for the uplink user-specific PA is running. If the timer for the uplink user-specific PA is running, processing may proceed to step 1310. Otherwise, processing may end at step 1330. In 1310, user-specific resource allocation information stored by the STA is extracted. In 1314, the number of User Info fields present in the received EHT Basic Trigger frame is calculated. In 1316, a User Info field counter is initialized to zero. In 1318, it is determined whether the AID of the STA matches the AID12 subfield value of the User Info field of the received EHT Basic Trigger frame. If the AID of the STA matches the AID12 subfield value, processing may proceed to step 1320. If the AID of the STA does not match the AID12 subfield value, processing may proceed to step 1322.At 1320, user-specific resource allocation information is obtained from the User Info field to prepare an EHT TB PPDU. At 1322, it is determined whether the AID12 subfield value of the User Info field indicates a User Info field for which it is eligible. If so, processing may proceed to step 1324. If not, processing may proceed to 1326. At 1324, a UORA procedure is performed. At 1326, the User Info field counter is incremented by one. At 1328, it is determined whether the User Info field counter is equal to the number of User Info fields in the received EHT Basic Trigger frame. If the User Info field counter is not equal to the number of User Info fields in the received EHT Basic Trigger frame, processing may return to step 1318 again. If the User Info field counter is equal to the number of User Info fields in the received EHT Basic Trigger frame, processing may end at 1330. It should be understood that steps 1318, 1322, 1326, and 1328 form a loop for the STA to cycle through and read all user information fields present in the received EHT Basic Trigger frame. At 1312, an EHT TB PPDU is prepared based on the common parameters (e.g., common parameters from the Common Info field of the received EHT Basic Trigger frame) and user-specific resource allocation information (e.g., user-specific resource allocation information stored by the STA if processing is from step 1310, or user-specific resource allocation information obtained from the User Info field if processing is from step 1320). At 1330, processing ends.

[0135] The processing of a received PA Trigger frame 720 at a STA according to the fourth embodiment is also shown in flow chart 840 of FIG. 8B.

[0136] The processing of a received data or management frame 730 carrying a PA Control subfield at a STA that is the intended recipient of the data or management frame 730 according to the fourth embodiment is also shown in flow chart 860 of FIG. 8C.

[0137] In the fourth embodiment as described above, the AP may transmit a first frame to update user-specific resource allocation information, excluding the identification information of the uplink user-specific PA (e.g., RU allocation information and SS allocation information), before it expires. If the user-specific resource allocation information of the uplink user-specific PA is updated before it expires and the intended STA fails to receive the updated information, there will be a mismatch between the AP and the intended STA regarding the information of the uplink user-specific PA. The AP can identify such a mismatch if an EHT TB PPDU is not received in response to the transmitted second frame. When the STA receives the first frame with complete information for the uplink user-specific PA of which it is one of the intended recipients, it starts or resets the timer for the uplink user-specific PA and stores or updates the information about the uplink user-specific PA. Similarly, the STA may also store or update common parameters in the Common Info field through this process. Advantageously, this allows the AP to perform error recovery from the information mismatch.

[0138] According to a third or fourth embodiment, the AP may transmit a PA Announcement frame to announce the downlink user-specific PA to one or more STAs. The user-specific assignment information of the downlink user-specific PA is not included in the EHT-SIG-B field of the EHT MU PPDU, but the RU information of the downlink user-specific PA is included in the EHT-SIG-B field of the EHT MU PPDU, which can be used by the intended STAs to identify the presence of the downlink user-specific PA in the EHT MU PPDU. That is, the initial or repeated transmission of the downlink user-specific PA is accompanied by partial control signaling (i.e., the RU information of the PA). This may advantageously reduce the overhead of the EHT-SIG-B.

[0139] 14A and 14B show a flow diagram 1400 illustrating communication between a STA 1040 with a downlink user-specific PA and an AP 1402 according to the third or fourth embodiment. A contention-based channel access procedure is indicated by block 1406, and a SIFS 1408 is shown. The AP 1402 may transmit a PA Announcement frame 1410, which may include downlink user-specific PA information for one or more STAs. At 1412, the STA 1402 may store or update RU information and user-specific assignment information for its own downlink user-specific PA. The AP 1402 may then transmit an EHT MU PPDU 1414, which may include a downlink user-specific PA transmission for the STA and may also include corresponding RU information but not corresponding user-specific assignment information. At 1416, the STA 1404 may receive the downlink user-specific PA transmission using the stored RU information and user-specific assignment information for the downlink user-specific PA. The STA 1404 may then transmit a BlockAck frame 1418. The PA Announcement frame and the EHT MU PPDU may be transmitted in different TXOPs.

[0140] The PA Announcement frame 1410 may be in the form of the PA Announcement frame 1200 as shown in Figure 12. Figure 15A shows the structure of the User Info field for a user-specific PA for downlink non-MU-MIMO assignment according to the third or fourth embodiment. Figure 15B shows the structure of the User Info field for a user-specific PA for downlink MU-MIMO assignment according to the third or fourth embodiment. As can be seen in both figures, the Direction field is set to 1 to indicate a downlink user-specific PA.

[0141] According to a third or fourth embodiment, a downlink user-specific PA may exist for a period of time after a PA Announcement frame announcing the downlink user-specific PA is transmitted. In one example, the downlink user-specific PA may exist until the end of the current TXOP. In another example, the downlink user-specific PA may exist for a determined number of service periods or beacon intervals. In yet another example, the Common Info field of the PA Announcement frame may include signaling for indicating the period of time the downlink user-specific PA announced by the PA Announcement frame will exist after the PA Announcement frame is transmitted. In such an example, the downlink user-specific PAs announced by the PA Announcement frame have the same expiration time. Alternatively, the User Info field corresponding to the downlink user-specific PA in the PA Announcement frame may include signaling for indicating the period of time the downlink user-specific PA will exist after the PA Announcement frame is transmitted. In another example, the downlink user-specific PAs announced by the PA Announcement frame may have different expiration times.

[0142] When a STA receives a PA Announcement frame that announces one or more downlink user-specific PAs for which the STA is the intended recipient (it will be understood that an EHT MU PPDU is used for downlink multi-user transmission and each assignment in the EHT MU PPDU has one or more intended STAs), the STA may start or reset a timer for each of the one or more downlink user-specific PAs and store or update the RU information and user-specific assignment information for the one or more downlink user-specific PAs.

[0143] Without RU information and / or user-specific assignment information for the downlink user-specific PA, the STA may not be able to properly receive the downlink user-specific PA transmission. Also, for error recovery, according to one embodiment, an exemplary rule may advantageously be that at least one MAC Protocol Data Unit (MPDU) requiring acknowledgment may be included in the downlink user-specific PA transmission immediately preceding the most recently transmitted PA Announcement frame announcing the downlink user-specific PA. If the AP does not receive a positive acknowledgment from the intended STA for the downlink user-specific PA transmission, the AP knows that the intended STA may not have RU information and / or downlink user-specific assignment information for the downlink user-specific PA, and the AP may then not schedule another transmission of the downlink user-specific PA and retransmit the PA Announcement frame to announce the downlink user-specific PA.

[0144] According to third and fourth embodiments, the EHT-SIG-B field of the EHT MU PPDU 1414 is coded separately on each L×20 MHz subchannel, where L=1 or 2. When the CBW is greater than 20 MHz, the EHT-SIG-B field with L=1 may have better EHT-SIG-B decoding performance compared to the EHT-SIG-B field with L=2. This is because the channel estimation used to decode the EHT-SIG-B field is based on the L-LTF transmitted in the 20 MHz bandwidth. Channel estimation by interpolation is required to decode the EHT-SIG-B field with L=2, which may degrade the performance of decoding the EHT-SIG-B field with L=2. On the other hand, compared to the EHT-SIG-B field with L=1, the EHT-SIG-B field with L=2 may have less EHT-SIG-B overhead, especially for larger CBWs. Furthermore, if the intended STAs of the EHT MU PPDU 1414 include at least one STA operating at 20 MHz, the EHT-SIG-B field with L=2 is not used because it cannot be decoded by STAs operating at 20 MHz. As a result, the AP may determine the value of L at its discretion and may advantageously include signaling in the EHT-SIG-A field of the EHT MU PPDU 1414 to indicate whether L takes the value of 1 or 2.

[0145] FIG. 16A shows a table illustrating how the number of EHT-SIG-B content channels depends on the values ​​of CBW and L according to various embodiments. As shown in FIG. 16A, if the CBW is 20 MHz, L can simply be 1 because the EHT-SIG-B field is coded every 20 MHz and there is only one EHT-SIG-B content channel. In embodiments where the CBW is 40 MHz, L may be assigned a value of 1 or 2 by the AP. If L is set to 1, there are two EHT-SIG-B content channels. If L is set to 2, there is only one EHT-SIG-B content channel. In embodiments where the CBW is 80 MHz, 80+80 MHz, 160 MHz, 160+160 MHz, or 320 MHz, there are two EHT-SIG-B content channels, regardless of the value of L. Further details are provided below.

[0146] Figure 16B shows a diagram of the mapping of one or two EHT-SIG-B content channels in a 40 MHz EHT MU PPDU. The number of EHT-SIG-B content channels depends on the values ​​of CBW and L, as shown in Figure 16A. A 40 MHz channel contains two 20 MHz subchannels. When L=1, there are two EHT-SIG-B content channels transmitted in the first and second 20 MHz subchannels, respectively. When L=2, there is only one EHT-SIG-B content channel.

[0147] Figure 16C shows a diagram of the mapping of two EHT-SIG-B content channels (i.e., EHT-SIG-B Content Channel 1 and EHT-SIG-B Content Channel 2) in an 80 MHz EHT MU PPDU. When L=1, in an 80 MHz channel containing four 20 MHz subchannels, EHT-SIG-B Content Channel 1 is replicated and transmitted in the first and third 20 MHz subchannels, and EHT-SIG-B Content Channel 2 is replicated and transmitted in the second and fourth 20 MHz subchannels. When L=2, in an 80 MHz channel containing two 40 MHz subchannels, EHT-SIG-B Content Channel 1 is transmitted in the first 40 MHz subchannel, and EHT-SIG-B Content Channel 2 is transmitted in the second 40 MHz subchannel.

[0148] Figure 16D shows a diagram of the mapping of two EHT-SIG-B content channels in an 80+80 MHz or 160 MHz EHT MU PPDU. When L=1, in an 80+80 MHz or 160 MHz channel containing eight 20 MHz subchannels, EHT-SIG-B content channel 1 is replicated and transmitted in the first, third, fifth, and seventh 20 MHz subchannels, and EHT-SIG-B content channel 2 is replicated and transmitted in the second, fourth, sixth, and eighth 20 MHz subchannels. When L=2, in an 80+80 MHz or 160 MHz channel containing four 40 MHz subchannels, EHT-SIG-B content channel 1 is replicated and transmitted in the first and third 40 MHz subchannels, and EHT-SIG-B content channel 2 is replicated and transmitted in the second and fourth 40 MHz subchannels.

[0149] Figure 16E shows a diagram of the mapping of two EHT-SIG-B content channels in a 160+160 MHz or 320 MHz EHT MU PPDU. When L=1, in a 160+160 MHz or 320 MHz channel containing 16 20 MHz subchannels, EHT-SIG-B Content Channel 1 is replicated and transmitted in the first, third, fifth, seventh, ninth, eleventh, thirteenth, and fifteenth 20 MHz subchannels, and EHT-SIG-B Content Channel 2 is replicated and transmitted in the second, fourth, sixth, eighth, tenth, twelfth, fourteenth, and sixteenth 20 MHz subchannels. When L=2, in a 160+160 MHz or 320 MHz channel containing eight 40 MHz subchannels, EHT-SIG-B Content Channel 1 is replicated and transmitted in the first, third, fifth and seventh 40 MHz subchannels, and EHT-SIG-B Content Channel 2 is replicated and transmitted in the second, fourth, sixth and eighth 40 MHz subchannels.

[0150] 17 shows an EHT-SIG-B field 1700 according to the third or fourth embodiment. The EHT-SIG-B field 1700 includes (or consists of) a Common field 1702 followed by a User Specific field 1704, which, if present, is referred to as the EHT-SIG-B content channel.

[0151] The Common field 1702 includes an RU Allocation subfield 1706, a Center 26-Tone RU subfield 1707, and a PA Bitmap subfield 1708. The RU Allocation subfield 1706 indicates RU information for each allocation, including downlink user-specific PAs. The RU information includes the RU location in the frequency domain, an indication of the RUs allocated for non-MU-MIMO or MU-MIMO allocations, and the number of users in the MU-MIMO allocation.

[0152] The RU Allocation subfield 1706 comprises N fields, where the value of N depends on the values ​​of CBW and L. In various embodiments, N can be 1 only for a CBW of 20 MHz. For a CBW of 40 MHz, N=1 when L=1, and N=2 when L=2. Regardless of the value of L, N=2 for a CBW of 80 MHz, N=4 for a CBW of 160 MHz or 80+80 MHz, and N=8 for a CBW of 320 MHz or 160+160 MHz. Each of the N fields in the RU Allocation subfield 1706 comprises 8-bit signaling to indicate RU allocation within the corresponding tone range. For example, when L=1 and CBW=80 MHz, for EHT-SIG-B content channel 1, the corresponding tone ranges are [-500:-259] and [17:258] for the first and second fields of the RU Allocation subfield 1706, respectively. For EHT-SIG-B content channel 2, the corresponding tone ranges are [-258:17] and [259:500] for the first and second fields of the RU Allocation subfield 1706, respectively.

[0153] In another example, when L=2 and CBW=80 MHz, for EHT-SIG-B content channel 1, the corresponding tone ranges are [-500:-259] and [-258:17], respectively, for the first and second fields of RU Allocation subfield 1706. For EHT-SIG-B content channel 2, the corresponding tone ranges are [17:258] and [259:500], respectively, for the first and second fields of RU Allocation subfield 1706. If a single RU in an 80 MHz PPDU overlaps with two or more of the tone ranges [-500:-259], [-258:-17], [17:258] and [259:500], the allocation may be signaled by only one of the N fields of the RU Allocation subfields of a single EHT-SIG-B content channel corresponding to one of the tone ranges that the RU overlaps in order to minimize EHT-SIG-B overhead.

[0154] The Center 26-Tone RU subfield 1707 contains M bits, where the value of M depends on the CBW. The Center 26-Tone RU subfield 1707 is present when the CBW is 80 MHz or greater, so M=0 when the CBW is 20 MHz or 40 MHz. When the CBW is 80 MHz, 80+80 MHz, or 160 MHz, M=1. When the CBW is 80 MHz, the Center 26-Tone RU subfields for both EHT-SIG-B Content Channel 1 and EHT-SIG-B Content Channel 2 indicate whether the user is assigned to a center 26-tone RU. When the CBW is 80+80 or 160 MHz, the Center 26-Tone RU subfield 1707 of EHT-SIG-B content channel 1 indicates whether the user is assigned to the center 26-tone RU with the lower frequency of 80 MHz, and the Center 26-Tone RU subfield 1707 of EHT-SIG-B content channel 2 indicates whether the user is assigned to the center 26-tone RU with the higher frequency of 80 MHz.

[0155] When the CBW is 160+160 MHz or 320 MHz, M = 2. The first bit of the Center 26-Tone RU subfield 1707 in EHT-SIG-B content channel 1 indicates whether the user is assigned to a center 26-tone RU with a lower frequency of 80 MHz within the lower frequency of 160 MHz, and the first bit of the Center 26-Tone RU subfield 1707 in EHT-SIG-B content channel 2 indicates whether the user is assigned to a center 26-tone RU with a higher frequency of 80 MHz within the lower frequency of 160 MHz. The second bit of the Center 26-Tone RU subfield 1707 in EHT-SIG-B content channel 1 indicates whether the user is assigned to a center 26-tone RU with a lower frequency of 80 MHz within the higher frequency of 160 MHz, and the second bit of the Center 26-Tone RU subfield 1707 in EHT-SIG-B content channel 2 indicates whether the user is assigned to a center 26-tone RU with a higher frequency of 80 MHz within the higher frequency of 160 MHz.

[0156] The PA Bitmap subfield 1708 indicates whether each of the user-specific allocations specified by the RU Allocation subfield 1706 and the Center 26-Tone RU subfield 1707 (if applicable) is persistent. A bit in the PA Bitmap subfield 1708 is set to 1 to indicate that the user-specific allocation corresponding to that bit is persistent. A bit in the PA Bitmap subfield 1708 is set to 0 to indicate that the user-specific allocation corresponding to that bit is not persistent.

[0157] The PA Bitmap subfield 1708 includes N bitmaps, each corresponding to one of the N RU Allocation subfields 1706 in the same EHT-SIG-B content channel. As mentioned above, the 1-bit Center 26-Tone RU subfield 1707 is persistent in the Common field 1702 when CBW=80, 80+80, or 160 MHz. As shown in Figure 16A, for CBW=80 MHz, the last bitmap (i.e., the second bitmap) in the PA Bitmap subfield 1708 indicates whether the user-specific allocation indicated by the Center 26-Tone RU subfield 1707 is persistent.

[0158] The EHT-SIG-A field may include a PA Presence subfield for each EHT-SIG-B content channel. The PA Presence subfield for an EHT-SIG-B content channel includes an N-bit bitmap, with the nth (N=1, 2, ..., N) bit indicating the presence of the nth bitmap in the PA Bitmap subfield for the EHT-SIG-B content channel. The nth bit in the PA Presence subfield of the EHT-SIG-A field may be set to 0 to indicate that the nth bitmap in the PA Bitmap subfield 1708 is not present in the EHT-SIG-B content channel, or set to 1 to indicate that the nth bitmap in the PA Bitmap subfield 1708 is present in the EHT-SIG-B content channel. As shown in diagram 1820 of Figure 18A, for CBW = 80 MHz, the first and second bits of the PA Presence subfield of the EHT-SIG-A field are set to 1 to indicate that the first and second bitmaps of the PA Bitmap subfield 1708 are present in the EHT-SIG-B content channel. To minimize overhead in the Common field, the bitmaps in the PA Bitmap subfield 1708 may not be present if all user-specific allocations indicated by the corresponding fields in the RU Allocation subfield 1706 and Center 26-Tone RU subfield 1707 (if applicable) are not persistent.

[0159] When CBW=80+80 or 160 MHz, the last bitmap (i.e., the fourth bitmap) of the PA Bitmap subfield 1708 for the EHT-SIG-B content channel also indicates whether the user-specific allocation indicated by the 1-bit Center 26-Tone RU subfield 1707 is persistent, as shown in diagram 1840 of FIG. 18B. The first, second, third, and fourth bits of the PA Presence subfield of the EHT-SIG-A field are set to 1 to indicate that the first, second, third, and fourth bitmaps of the PA Bitmap subfield 1708 are present in the EHT-SIG-B content channel. The bitmap in the PA Bitmap subfield 1708 is not present if all user-specific allocations indicated by the corresponding fields of the RU Allocation subfield 1706 and the Center 26-Tone RU subfield 1707 (if applicable) are not persistent.

[0160] As described above, when CBW=160+160 or 320 MHz, the 2-bit Center 26-Tone RU subfield 1707 is present in the Common field 1702. In this case, the fourth bitmap of the PA Bitmap subfield 1708 also indicates whether the user-specific allocation indicated by the first bit of the Center 26-Tone RU subfield 1707 is persistent, and the last bitmap of the PA Bitmap subfield 1708 indicates whether the user-specific allocation indicated by the second bit of the Center 26-Tone RU subfield 1707 is persistent. To minimize overhead in the Common field, the bitmap of the PA Bitmap subfield 1708 may not be present if all user-specific allocations indicated by the corresponding fields of the RU Allocation subfield 1706 and the corresponding bits of the Center 26-Tone RU subfield 1707 (if applicable) are not persistent.

[0161] The Common field 1702 may not be present in the case of full-bandwidth MU-MIMO transmission. In this case, RU information for the MU-MIMO allocation (e.g., the number of users in the MU-MIMO allocation) may be signaled in the EHT-SIG-A field. Whether each user-specific portion of the MU-MIMO allocation is persistent may also be signaled in the EHT-SIG-A field.

[0162] 19A shows a first example of the coding structure of the Common field 1702 according to the third or fourth embodiment. As described above, the Common field 1702 includes an RU Allocation subfield 1706, a Center 26-Tone RU subfield 1707, and a PA Bitmap subfield 1708. In the first example, all subfields of the Common field 1702 are coded together. As described above, each of the N fields of the RU Allocation subfield 1706 is 8-bit signaling, and therefore the RU Allocation subfield 1706 has N×17 bits, where N=1, 2, 4, or 8. The Center 26-Tone RU subfield 1707 has M bits, where M=0, 1, or 2. Each of the N fields of the RU Allocation subfield 1706 can indicate up to 17 user-specific allocations. Thus, in the first example, each of the PA Bitmap subfields 1708 has a size of (N×17+M) bits.

[0163] The Common field 1702 has a CRC (Cyclic Redundancy Check) subfield 1722 added for BCC encoding / decoding purposes, and a Tail subfield 1724. The CRC subfield 1722 has a size of 4 bits, and the Tail subfield 1724 has a size of 6 bits. That is, the size of the Common field 1702 is the sum of the sizes of the RU Allocation subfield 1706, the Center 26-Tone RU subfield 1707, the PA Bitmap subfield 1708, the CRC subfield 1722, and the Tail subfield 1724. Therefore, in the first example, the size of the Common field 1702 can be determined after decoding the EHT-SIG-A field, because the values ​​of N and M can be derived from the values ​​of CBW and L indicated in the EHT-SIG-A field.

[0164] Figure 19B shows a second example of the encoding structure of the Common field 1702 according to the third or fourth embodiment. The Common field 1702 is divided into two Common Block fields, a first Common Block field 1710a and a second Common Block field 1710b, which are encoded separately. The first Common Block field 1710a includes an RU Allocation subfield 1706 and a Center 26-Tone RU subfield 1707. The size of the first Common Block field 1710a can be derived after decoding the EHT-SIG-A field, since the values ​​of N and M can be derived from the values ​​of CBW and L indicated in the EHT-SIG-A field. The first Common Block field 1702a also includes a 4-bit CRC field 1722a and a 6-bit Tail field 1724a for BCC encoding / decoding purposes. The second Common Block field 1702b includes a PA Bitmap subfield 1708. The second Common Block field 1710b also includes a 4-bit CRC field 1722b and a 6-bit Tail field 1724b for BCC encoding / decoding purposes.

[0165] In the second example, the PA Bitmap subfield 1708 is (Σ n=1 N L n +M bits), and L n is equal to the number of user-specific allocations indicated by the nth field of the RU Allocation subfield 1706. The size of the second Common Block field 1710b can be determined after the first Common Block field 1710a is decoded.

[0166] Compared with the first example as shown in FIG. 19A, the second example as shown in FIG. 19B has a higher implementation complexity regarding the decoding of the Common field 1702. Also, when the first example and the second example have the same Common field overhead, the first example is preferred.

[0167] As shown in FIGS. 19A and 19B, when comparing, Σ i=n N L n When <N×17 - 10, the second example has less Common field overhead than the first example. The following can be observed. · When N = 1, the second example may be better when L1 < 7. Otherwise, the first example is better. · When N = 2, the second example may be better when Σ n=1 2 L n <24. Otherwise, the first example is better. · When N = 4, the second example may be better when Σ n=1 4 L n <58. Otherwise, the first example is better. · When N = 8, the second example may be better when Σ n=1 8 L n <126. Otherwise, the first example is better.

[0168] Obviously, whether the first example or the second example is used in the Common field of the EHT MU PPDU should be at the discretion of the AP according to the CBW and RU allocation of the EHT MU PPDU. As a result, it is effective to add one-bit signaling for each EHT-SIG-B content channel in the EHT-SIG-A field of the EHT MU PPDU to indicate whether the first example or the second example is used in the corresponding EHT-SIG-B content channel.

[0169] In FIG. 17, the User Specific field 1704 includes (or consists of) one or more User fields for non-MU-MIMO assignments and / or MU-MIMO assignments, such as, for example, User field 0 (1710), User field 1 (1712), User field 2 (1714), User field 3 (1716), and User field 4 (1718).

[0170] The User field contains user information indicating a user-specific allocation (i.e., user-specific allocation information). For a non-MU-MIMO allocation, the number of spatial streams (NSTS), transmit beamforming (TxBF) information, MCS, DCM information, and error control coding information may be included. For a MU-MIMO allocation, the NSTS, start spatial stream, MCS, and error control coding information may be included. One User field may be addressed to a STA (similar to an EHT MU PPDU, in an EHT MU PPDU, a STA is addressable only by a single User field. As a result, when a STA receives an EHT MU PPDU, it stops parsing the User Specific fields once it identifies its own User field). For example, User field 0 (1710) may provide user-specific allocation information for Allocation 0. For example, User field 1 (1712), User field 2 (1714), and User field 3 (1716) may provide user-specific allocation information for Allocation 1 with three MU-MIMO users. For example, User field 4 (1718) may provide user-specific allocation information for Allocation 2.

[0171] 19C shows a first example of the coding structure of the Common field 502 according to the embodiment shown in FIG. 3B. As described above, the Common field 1702 includes an RU Allocation subfield 1706, a Center 26-Tone RU subfield 1707, and a PA Bitmap subfield 1708. In the first example, all subfields of the Common field 1702 are coded together. As described above, each of the N fields of the RU Allocation subfield 1706 is 8-bit signaling, and therefore the RU Allocation subfield 1706 has N×17 bits, where N=1, 2, 4, or 8. The Center 26-Tone RU subfield 1707 has M bits, where M=0, 1, or 2. Each of the N fields of the RU Allocation subfield 1706 can signal up to 17 user-specific allocations. Thus, in the first example, each of the PA Bitmap subfields 1708 has a size of (N×9+M) bits.

[0172] The Common field 1702 has a CRC (Cyclic Redundancy Check) subfield 1722 added for BCC encoding / decoding purposes, and a Tail subfield 1724. The CRC subfield 1722 has a size of 4 bits, and the Tail subfield 1724 has a size of 6 bits. That is, the size of the Common field 1702 is the sum of the sizes of the RU Allocation subfield 1706, the Center 26-Tone RU subfield 1707, the PA Bitmap subfield 1708, the CRC subfield 1722, and the Tail subfield 1724. Therefore, in the first example, the size of the Common field 1702 can be determined after decoding the EHT-SIG-A field, because the values ​​of N and M can be derived from the values ​​of CBW and L indicated in the EHT-SIG-A field.

[0173] Figure 19B shows a second example of the encoding structure of the Common field 502 according to the embodiment shown in Figure 3B. The Common field 1702 is divided into two Common Block fields, a first Common Block field 1710a and a second Common Block field 1710b, which are encoded separately. The first Common Block field 1710a includes an RU Allocation subfield 1706 and a Center 26-Tone RU subfield 1707. The size of the first Common Block field 1710a can be derived after decoding the EHT-SIG-A field, since the values ​​of N and M can be derived from the values ​​of CBW and L indicated in the EHT-SIG-A field. The first Common Block field 1702a also includes a 4-bit CRC field 1722a and a 6-bit Tail field 1724a for BCC encoding / decoding purposes. The second Common Block field 1702b includes a PA Bitmap subfield 1708. The second Common Block field 1710b also includes a 4-bit CRC field 1722b and a 6-bit Tail field 1724b for BCC encoding / decoding purposes.

[0174] In the second example, each of the Persistent Allocation Bitmap subfield 508 and the Recurring Transmission Bitmap subfield 509 is (Σ n=1 N L n +M) bits, and L n is equal to the number of allocations indicated by the nth field of the RU Allocation subfield 506. The size of the second Common Block field 502b can be determined after the first Common Block field 502a is decoded.

[0175] Compared with the first example as shown in FIG. 19C, the second example as shown in FIG. 19D has a higher implementation complexity regarding the decoding of the Common field 1702. Also, when the first example and the second example have the same Common field overhead, the first example is preferred.

[0176] As shown in FIGS. 19C and 19D, by comparison, Σ i=n N L n <If it is N×9 - 5, the second example has less Common field overhead than the first example. The following can be observed. · When N = 1, the second example may be better when L1 < 4. Otherwise, the first example is better. · When N = 2, the second example may be better when Σ n=1 2 L n <13. Otherwise, the first example is better. · When N = 4, the second example may be better when Σ n=1 4 L n <31. Otherwise, the first example is better. · When N = 8, the second example may be better when Σ n=1 8 L n <67. Otherwise, the first example is better.

[0177] Effectively, there is no User field for the downlink persistent allocation including repeated transmissions, which can reduce the overhead.

[0178] 19E shows a first example of the coding structure of the Common field 1702 according to the embodiment shown in FIG. 3C. As described above, the Common field 1702 includes an RU Allocation subfield 1706, a Center 26-Tone RU subfield 1707, and a PA Bitmap subfield 1708. In the first example, all subfields of the Common field 1702 are coded together. As described above, each of the N fields of the RU Allocation subfield 1706 is 8-bit signaling, and therefore the RU Allocation subfield 1706 has N×8 bits, where N=1, 2, 4, or 8. The Center 26-Tone RU subfield 1707 has M bits, where M=0, 1, or 2. Each of the N fields of the RU Allocation.

[0179] The Common field 1702 has a CRC (Cyclic Redundancy Check) subfield 1722 added for BCC encoding / decoding purposes, and a Tail subfield 1724. The CRC subfield 1722 has a size of 4 bits, and the Tail subfield 1724 has a size of 6 bits. That is, the size of the Common field 1702 is the sum of the sizes of the RU Allocation subfield 1706, the Center 26-Tone RU subfield 1707, the PA Bitmap subfield 1708, the CRC subfield 1722, and the Tail subfield 1724. Therefore, in the first example, the size of the Common field 1702 can be determined after decoding the EHT-SIG-A field, because the values ​​of N and M can be derived from the values ​​of CBW and L indicated in the EHT-SIG-A field.

[0180] Figure 19E shows a second example of the encoding structure of the Common field 1702 according to the embodiment shown in Figure 3C. The Common field 1702 is divided into two Common Block fields, a first Common Block field 1710a and a second Common Block field 1710b, which are encoded separately. The first Common Block field 1710a includes an RU Allocation subfield 1706 and a Center 26-Tone RU subfield 1707. The size of the first Common Block field 1710a can be derived after decoding the EHT-SIG-A field, since the values ​​of N and M can be derived from the values ​​of CBW and L indicated in the EHT-SIG-A field. The first Common Block field 1702a also includes a 4-bit CRC field 1722a and a 6-bit Tail field 1724a for BCC encoding / decoding purposes. The second Common Block field 1702b includes a PA Bitmap subfield 1708. The second Common Block field 1710b also includes a 4-bit CRC field 1722b and a 6-bit Tail field 1724b for BCC encoding / decoding purposes.

[0181] In the second example, the PA Bitmap subfield 1708 is (Σ n=1 N L n +M) bits, and L n is equal to the number of allocations indicated by the nth field of the RU Allocation subfield 1706. The size of the second Common Block field 1710b can be determined after the first Common Block field 1710a is decoded.

[0182] Compared with the first example as shown in FIG. 19E, the second example as shown in FIG. 19F has a higher implementation complexity regarding the decoding of the Common field 1702. Also, when the first example and the second example have the same Common field overhead, the first example is preferred.

[0183] As shown in FIGS. 19E and 19F, when comparing, Σ i=n N L n <If it is N×9 - 10, the second example has less Common field overhead than the first example. The following can be observed. · When N = 1, the first example is better. · When N = 2, the second example may be better if Σ n=1 2 L n <is < 8. Otherwise, the first example is better. · When N = 4, the second example may be better if Σ n=1 4 L n <is < 26. Otherwise, the first example is better. · When N = 8, the second example may be better if Σ n=1 8 L n <is < 62. Otherwise, the first example is better.

[0184] Obviously, whether the first example or the second example is used in the Common field of the EHT MU PPDU should be at the discretion of the AP according to the CBW and RU allocation of the EHT MU PPDU. As a result, it is effective to add 1-bit signaling for each EHT-SIG-B content channel in the EHT-SIG-A field of the EHT MU PPDU to indicate whether the first example or the second example is used in the corresponding EHT-SIG-B content channel.

[0185] In FIG. 17, the User Specific field 1704 includes (or consists of) one or more User fields for non-MU-MIMO assignments and / or MU-MIMO assignments, such as, for example, User field 0 (1710), User field 1 (1712), User field 2 (1714), User field 3 (1716), and User field 4 (1718).

[0186] The User field contains user information indicating a user-specific allocation (i.e., user-specific allocation information). For a non-MU-MIMO allocation, the number of spatial streams (NSTS), transmit beamforming (TxBF) information, modulation and coding scheme (MCS), dual-carrier modulation (DCM) information, and error control coding information may be included. For a MU-MIMO allocation, the NSTS, start spatial stream, MCS, and error control coding information may be included. One User field may be addressed to a STA (similar to an EHT MU PPDU, in an EHT MU PPDU, a STA is addressable only by a single User field. As a result, when a STA receives an EHT MU PPDU, it stops parsing the User Specific fields once it identifies its own User field). For example, User field 0 (1710) may provide user-specific allocation information for Allocation 0. For example, User field 1 (1712), User field 2 (1714), and User field 3 (1716) may provide user-specific allocation information for Allocation 1 by three MU-MIMO users. For example, User field 4 (1718) may provide user-specific allocation information for Allocation 2.

[0187] Table 1 shows the format of the User field for non-MU-MIMO allocation, where BCC is Binary Convolutional Code and LDPC is Low Density Parity Code. Table 2 shows the format of the User field for MU-MIMO allocation.

[0188] [Table 1]

[0189] [Table 2]

[0190] Without RU information and / or user-specific assignment information for its own persistent assignment, a STA may not be able to properly receive repeated transmissions of the persistent assignment. Also, for error recovery, according to one embodiment, an example rule may be that at least one MPDU (Medium Access Control (MAC) Protocol Data Unit) requiring acknowledgment may be included in the initial transmission of the persistent assignment. If the AP does not receive a positive acknowledgment from the STA for the initial transmission of the persistent assignment, the STA may not have RU information and / or user-specific assignment information for the persistent assignment, and the AP may not schedule repeated transmissions of the persistent assignment.

[0191] According to the third or fourth embodiment, the User field of the downlink user-specific PA is not in the User Specific field, which can reduce overhead.

[0192] FIG. 20A shows a diagram 2000 of overhead reduction of the User Specific field for the third and fourth embodiments. The PA Bitmap subfield 2002 is provided as 00101. User field 0 (2006) of the User Specific field provides non-MU-MIMO allocation 0, which is not persistent (because the first bit is 0 in the PA Bitmap subfield 2002), and User field 0 (2006) is provided in the User Specific field. User field 1 (2008), User field 2 (2010), and User field 3 (2012) provide three user-specific allocations of MU-MIMO allocation 1. The first user-specific allocation of MU-MIMO allocation 1 is not persistent (because the second bit is 0 in the PA Bitmap subfield 2002), and User field 1 (2008) is provided in the User Specific field. The second user-specific assignment of MU-MIMO assignment 1 is persistent (because the third bit is 1 in PA Bitmap subfield 2002), and User field 2 (2010) is not provided in the User Specific field. The third user-specific assignment of MU-MIMO assignment 1 is not persistent (because the fourth bit is 0 in PA Bitmap subfield 2002), and User field 3 (2012) is provided in the User Specific field. User field 4 (2014) of the User Specific field provides non-MU-MIMO assignment 2, which is persistent (because the fifth bit is 1 in PA Bitmap subfield 2002), and User field 4 (2014) is not provided in the User Specific field, which advantageously reduces overhead.

[0193] 20B shows a diagram 2200 of overhead reduction of the User Specific field for the third and fourth embodiments. The PA Bitmap subfield 2002 is provided as 001. User field 0 (2006) of the User Specific field provides Allocation 0, which is not persistent (because the first bit of the PA Bitmap subfield 2002 is 0), and User field 0 (2006) is provided in the User Specific field. User field 1 (2008), User field 2 (2010), and User field 3 (2012) provide Allocation 1 with three MU-MIMO users, which is not persistent (because the second bit in the PA Bitmap subfield 2002 is 0), and User field 1 (2008), User field 2 (2010), and User field 3 (2012) are provided in the User Specific field. The third bit of the PA Bitmap subfield 2002 is 1, so Allocation 2 is PA, and User field 4 (2014) is not provided in the User Specific field, effectively reducing overhead.

[0194] FIG. 20C shows a diagram 2050 of overhead reduction of the User Specific field in another example of the first to fourth embodiments. The PA Bitmap subfield 2002 is provided as 010. User field 0 (2056) of the User Specific field provides Allocation 0, which is not persistent (because the first bit of the PA Bitmap subfield 2052 is 0), and User field 0 (2056) is provided in the User Specific field. User field 1 (2058), User field 2 (2060), and User field 3 (2062) provide Allocation 1 with three MU-MIMO users, which is persistent (because the second bit of the PA Bitmap subfield 2052 is 1), and User field 1 (2058), User field 2 (2060), and User field 3 (2062) are not provided in the User Specific field, which effectively reduces overhead. The third bit of the PA Bitmap subfield 2052 is 0, so Allocation 2 is PA, and User field 4 (2064) is provided as a User Specific field.

[0195] FIG. 21 shows a flowchart 2100 illustrating processing of a received EHT MU PPDU at a STA according to the third or fourth embodiment. Processing may start at 2102. In 2104, the EHT-SIG-A and EHT-SIG-B fields of the received EHT MU PPDU may be demodulated and decoded. In 2106, the allocated RU(s) may be determined, which may be performed by checking the RU Allocation subfield and Center 26-Tone subfield (if present) of the EHT-SIG-B field. This step may be skipped in the case of full-bandwidth MU-MIMO transmission. In 2108, the number of User fields in the User Specific field may be calculated, and the PA Presence subfield of the EHT-SIG-A field and the PA Bitmap subfield of the EHT-SIG-B field may be considered to exclude User fields corresponding to downlink user-specific PAs. In 2110, a User field counter may be initialized to 0 (zero). At 2112, it may be determined whether the STA ID of the STA matches the value of the STA-ID subfield. If the STA ID of the STA matches the value of the STA-ID subfield, processing may proceed to step 2116. If the STA ID of the STA does not match the value of the STA-ID subfield, processing may proceed to step 2122. At 2116, user-specific assignment information may be obtained. At 2120, a corresponding assignment transmission may be received in the Data field. At 2122, a User field counter may be incremented by one. At 2124, it may be determined whether the User field counter is equal to the number of User fields in the User Specific field. If it is determined that the User field counter is equal to the number of User fields in the User Specific field, processing may proceed to step 2126.If it is determined that the User field counter is not equal to the number of User fields in the User Specific field, processing may return to step 2112. In 2126, it may be determined whether any timers for the downlink user-specific PA are running. If it is determined that at least one timer for the downlink user-specific PA is running, processing may proceed to step 2128. If it is determined that no timers for the downlink user-specific PA are running, processing may end at step 2132. In 2128, it may be determined whether any of the assigned RUs for the downlink user-specific PA match the stored RU information for the downlink user-specific PA with a running timer, and the assigned RUs for the downlink user-specific PA may be determined by checking the PA Presence subfield of the EHT-SIG-A field and the PA Bitmap subfield of the EHT-SIG-B field. If it is determined that one of the assigned RUs of the downlink user-specific PA matches the stored RU information for the downlink user-specific PA with a running timer, the process may proceed to step 2130. If it is determined that none of the RUs assigned to the downlink user-specific PA matches the stored RU information for any downlink user-specific PA with a running timer, the process may end at 2132. At step 2130, the most recently stored user-specific assignment information for the matching RU is extracted, and the process proceeds to step 2120. At 2132, the process ends.

[0196] 22 shows a flowchart illustrating communication between an AP 2202 and a STA 2204 using a downlink user-specific PA according to a fifth embodiment. A contention-based channel access procedure is indicated by block 2206, and a SIFS 2208 is shown. The AP 2202 may transmit an EHT MU PPDU 2210, which may include an initial transmission of the downlink user-specific PA for the STA and may also include corresponding RU information and user-specific assignment information. The AP 2202 may then transmit an EHT MU PPDU 2214, which may include a repeated transmission of the downlink user-specific PA for the STA and may also include corresponding RU information, but not corresponding user-specific assignment information. In 2216, the STA 2204 may receive the initial transmission of the downlink user-specific PA and store the RU information and user-specific assignment information for the downlink user-specific PA. The STA 2204 may then transmit a BlockAck frame 2218. At 2220, the STA 2204 may receive a repeated transmission of the downlink user-specific PA using the stored RU information and user-specific assignment information for the downlink user-specific PA. The STA 2204 may then transmit a BlockAck frame 2222.

[0197] 23 shows an EHT-SIG-B field 2300 according to a fifth embodiment. The EHT-SIG-B field 2300 includes (or consists of) a Common field 2302, which together are referred to as the EHT-SIG-B Content Channel, followed by a User Specific field 2304, if present.

[0198] The Common field 2302 includes an RU Allocation subfield 2306, a Center 26-Tone RU subfield 2307, a PA Bitmap subfield 2308, and a Recurring Transmission Bitmap subfield 2309. The RU Allocation subfield 2306 indicates RU information for each user-specific allocation, including a downlink user-specific PA.

[0199] The PA Bitmap subfield 2308 of the Common field 2302 is the same as the PA Bitmap subfield 1708 of the Common field 1702, as shown in Figure 17. The EHT-SIG-A field may include a PA Bitmap Presence subfield for each EHT-SIG-B content channel.

[0200] The Recurring Transmission Bitmap subfield 2309 indicates whether each user-specific allocation specified by the RU Allocation subfield 2306 includes an initial or recurring transmission. A bit in the Recurring Transmission Bitmap subfield 2309 is set to 0 to indicate that the user-specific allocation corresponding to that bit includes an initial transmission. An initial transmission represents a transmission of a non-user-specific PA or the first transmission of a user-specific PA. If the user-specific allocation corresponding to that bit is not persistent, the bit in the Recurring Transmission Bitmap subfield 2309 is set to 0. A bit in the Recurring Transmission Bitmap subfield 2309 is set to 1 to indicate that the user-specific allocation corresponding to that bit includes a recurring transmission. When a bit in the Recurring Transmission Bitmap subfield 2309 is set to 1, the User field for the user-specific allocation corresponding to that bit is not present in the User Specific field 2304.

[0201] The Recurring Transmission Bitmap subfield 2309 includes N bitmaps corresponding to the N fields of the RU Allocation subfields in the same EHT-SIG-B content channel. When CBW=80, 80+80, or 160 MHz, the last bitmap of the Recurring Transmission Bitmap subfield 2309 also indicates whether the user-specific allocation indicated by the one-bit Center 26-Tone RU subfield 2307 includes repeated transmission. When CBW=160+160, or 320 MHz, the fourth bitmap of the Recurring Transmission Bitmap subfield 2309 also indicates whether the user-specific allocation indicated by the first bit of the two-bit Center 26-Tone RU subfield 2307 includes repeated transmission, and the last bitmap of the Recurring Transmission Bitmap subfield 2309 also indicates whether the user-specific allocation indicated by the second bit of the two-bit Center 26-Tone RU subfield 2307 includes repeated transmission. The bitmap in the Recurring Transmission Bitmap subfield 2309 is not present if all user-specific allocations specified by the corresponding field in the RU Allocation subfield 2306 and the corresponding bit in the Center 26-Tone RU subfield 2307 (if applicable) do not include recurring transmissions.

[0202] The Recurring Transmission Bitmap subfield 2309 is mapped to the RU Allocation subfield 2306 and the Center 26-Tone RU subfield 2307 in the same manner as the PA Bitmap subfield 2308, as shown in Figures 18A and 18B.

[0203] Alternatively, an Initial Transmission Bitmap subfield may be provided in, for example, the Common field 2302, indicating whether each of the user-specific allocations specified by the RU Allocation subfield 2306 includes an initial or repeat transmission. To indicate that the user-specific allocation corresponding to a bit includes an initial transmission, the bit is set to 1. To indicate that the user-specific allocation corresponding to a bit includes a repeat transmission, the bit is set to 0.

[0204] The EHT-SIG-A field may include a Recurring Transmission Presence subfield for each EHT-SIG-B content channel. The Recurring Transmission Presence subfield for an EHT-SIG-B content channel includes an N-bit bitmap, where the nth (n=1, 2, ..., N) bit indicates the presence of the nth bitmap of the Recurring Transmission Bitmap subfield 2309 in the EHT-SIG-B content channel. The nth bit of the Recurring Transmission Presence subfield in the EHT-SIG-A field is set to 0 to indicate that the nth bitmap of the Recurring Transmission Bitmap subfield 2309 is not in the EHT-SIG-B content channel, and is set to 1 to indicate that the nth bitmap of the Recurring Transmission Bitmap subfield 2309 is present in the EHT-SIG-B content channel. When the nth bit of the Persistent Allocation Presence subfield of the EHT-SIG-A field is set to 0, the nth bit of the Recurring Transmission Presence subfield in the same EHT-SIG-B content channel is also set to 0 (i.e., the nth bitmap of the Recurring Transmission Bitmap subfield 2309 is also not present in the same EHT-SIG-B content channel).

[0205] The Common field 2302 may not be present in the case of full-bandwidth MU-MIMO transmission. In this case, RU information of the MU-MIMO allocation (e.g., the number of users in the MU-MIMO allocation) may be signaled in the EHT-SIG-A field. Furthermore, whether each user-specific portion of the MU-MIMO allocation is persistent and whether each user-specific portion of the MU-MIMO allocation includes repeated transmissions may also be signaled in the EHT-SIG-A field.

[0206] Figure 24A shows a first example of the coding structure of the Common field 2302 according to the fifth embodiment. As described in Figure 23, the Common field 2302 includes an RU Allocation subfield 2306, a Center 26-Tone RU subfield 2307, a PA Bitmap subfield 2308, and a Recurring Transmission Bitmap subfield 2309. In the first example, all subfields of the Common field 2302 are coded together. As described above, each of the N fields of the RU Allocation subfield 2306 is 8-bit signaling, so the RU Allocation subfield 2306 has N x 8 bits, where N = 1, 2, 4, or 8. The Center 26-Tone RU subfield 2307 has M bits, where M = 0, 1, or 2. Each of the N fields of the RU Allocation subfield 2306 can indicate up to 17 allocations. Thus, in the first example, each of the PA Bitmap subfield 2308 or the Recurring Transmission Bitmap subfield 2309 has a size of (N×17+M) bits.

[0207] The Common field 2302 has a CRC subfield 2322 and a Tail subfield 2324 that are added for the purpose of BCC encoding / decoding. The CRC subfield 2322 has a size of 4 bits, and the Tail subfield 2324 has a size of 6 bits. That is, the size of the Common field 2302 is the sum of the sizes of the RU Allocation subfield 2306, the Center 26-Tone RU subfield 2307, the PA Bitmap subfield 2308, the Recurring Transmission Bitmap subfield 2309, the CRC subfield 2322, and the Tail subfield 2324. Therefore, in the first example, the size of the Common field 2302 can be determined after decoding the EHT-SIG-A field, because the values ​​of N and M can be derived from the values ​​of CBW and L indicated in the EHT-SIG-A field.

[0208] Figure 24B shows a second example of the encoding structure of the Common field 2302 according to the fifth embodiment. The Common field 2302 is divided into two Common Block fields, a first Common Block field 2320a and a second Common Block field 2320b, which are encoded separately. The first Common Block field 2320a includes an RU Allocation subfield 2306 and a Center 26-Tone RU subfield 2307. The size of the first Common Block field 2320a can be derived after decoding the EHT-SIG-A field, since the values ​​of N and M can be derived from the values ​​of CBW and L indicated in the EHT-SIG-A field. The first Common Block field 2320a also includes a 4-bit CRC field 2322a and a 6-bit Tail field 2324a for BCC encoding / decoding purposes. The second Common Block field 2320b includes a PA Bitmap subfield 2308 and a Recurring Transmission Bitmap subfield 2309. The second Common Block field 2320b also includes a 4-bit CRC field 2322b and a 6-bit Tail field 2324b for BCC encoding / decoding purposes.

[0209] In the second example, each of the PA Bitmap subfield 2308 and the Recurring Transmission Bitmap subfield 2309 is (Σ n=1 N L n +M) bits, and L n is equal to the number of user-specific allocations indicated by the nth field of the RU Allocation subfield 2306. The size of the second Common Block field 2320b can be determined after the first Common Block field 2320a is decoded.

[0210] Compared with the first example as shown in FIG. 24A, the second example as shown in FIG. 24B has a higher implementation complexity regarding the decoding of the Common field 2302. Also, when the first example and the second example have the same Common field overhead, the first example is preferred.

[0211] As shown in FIGS. 24A and 24B, by comparison, Σ i=n N L n If <N×17 - 5, the second example has less Common field overhead than the first example. The following can be observed. · When N = 1, the second example may be better when L1 < 12. Otherwise, the first example is better. · When N = 2, the second example may be better when Σ n=1 2 L n <29. Otherwise, the first example is better. · When N = 4, the second example may be better when Σ n=1 4 L n <63. Otherwise, the first example is better. · When N = 8, the second example may be better when Σ n=1 8 L n <131. Otherwise, the first example is better.

[0212] Obviously, whether the first example or the second example is used in the Common field of the EHT MU PPDU should be at the discretion of the AP according to the CBW and RU allocation of the EHT MU PPDU. As a result, it is effective to add 1-bit signaling for each EHT-SIG-B content channel in the EHT-SIG-A field of the EHT MU PPDU to indicate whether the first example or the second example is used in the corresponding EHT-SIG-B content channel.

[0213] The User Specific field 2304 includes (or consists of) one or more User fields for non-MU-MIMO and / or MU-MIMO assignments. The User fields of the User Specific field 2304 are the same as those of the User Specific field 1704 as shown in FIG. 17.

[0214] Upon receiving an EHT MU PPDU containing the first transmission of a downlink user-specific PA for which the STA is the intended recipient, the STA may start or reset a timer for the downlink user-specific PA and store or update RU information and user-specific allocation information for the downlink user-specific PA.

[0215] In the absence of RU information and / or user-specific assignment information for the downlink user-specific PA, the STA may not be able to properly receive the repeated transmission of the downlink user-specific PA. Also, for error recovery, according to one embodiment, advantageously, an exemplary rule may be that at least one MPDU requiring acknowledgment may be included in the initial transmission of the downlink user-specific PA. If the AP does not receive a positive acknowledgment from the STA for the initial transmission of the downlink user-specific PA, the AP knows that the STA may not have RU information and / or user-specific assignment information for the downlink user-specific PA, and thereafter, the AP may not schedule repeated transmissions of the downlink user-specific PA.

[0216] FIG. 25 shows a diagram 2500 of overhead reduction for the User Specific field according to a fifth embodiment. A Recurring Transmission Bitmap subfield 2504 is provided as 00101. User field 0 (2506) of the User Specific field provides non-MU-MIMO allocation 0, which is non-persistent (because the second bit of the PA Bitmap subfield 2502 is 1), and User field 0 (2506) is provided in the User Specific field. User field 1 (2508) provides the first user-specific allocation of MU-MIMO allocation 1, which is persistent (because the second bit of the PA Bitmap subfield 2502 is 1). Because the second bit of the Recurring Transmission Bitmap subfield 2504 is 0, the transmission according to the first user-specific allocation of MU-MIMO allocation 1 is not a recurring transmission, and therefore User field 1 (2508) is provided in the User Specific field. User field 2 (2510) provides a second user-specific allocation of MU-MIMO allocation 1 that is persistent (because the third bit of PA Bitmap subfield 2502 is 1). Because the third bit of Recurring Transmission Bitmap subfield 2504 is 1, the transmission according to the second user-specific allocation of MU-MIMO allocation 1 is a recurring transmission, and therefore User field 2 (2510) is not provided in the User Specific field. User field 3 (2512) provides a third user-specific allocation of MU-MIMO allocation 1 that is non-persistent (because the fourth bit of PA Bitmap subfield 2502 is 0), and therefore User field 3 (2512) is provided in the User Specific field. User field 4 (2514) of the User Specific field provides non-MU-MIMO allocation 2 that is persistent (because the fifth bit of PA Bitmap subfield 2502 is 1).Since the fifth bit of the Recurring Transmission Bitmap subfield 2504 is 1, indicating that the transmission over non-MU-MIMO allocation 2 is a recurring transmission, User field 4 (2514) is not provided in the User Specific field, which effectively reduces overhead.

[0217] FIG. 26 shows a flowchart 2600 illustrating processing of a received EHT MU PPDU at a STA according to the fifth embodiment. Processing may start at 2602. At 2604, the EHT-SIG-A and EHT-SIG-B fields of the received EHT MU PPDU may be demodulated and decoded. At 2606, the allocated RUs may be determined, which may be performed by checking the RU Allocation subfield of the EHT-SIG-B field; this step may be skipped in the case of full-bandwidth MU-MIMO transmission. At 2608, the number of User fields in the User Specific field may be calculated, and the Recurring Transmission Presence subfield of the EHT-SIG-A field and the Recurring Transmission Bitmap subfield of the EHT-SIG-B field may be considered to exclude User fields corresponding to repeated transmissions. At 2610, a User field counter may be initialized to 0 (zero). In 2612, it may be determined whether the STA ID of the STA matches the value of the STA-ID subfield. The STA ID is an identifier of the STA and uniquely identifies the STA in an associated Basic Service Set (BSS). If the STA ID of the STA matches the value of the STA-ID subfield, processing may proceed to step 2614. If the STA ID of the STA does not match the value of the STA-ID subfield, processing may proceed to step 2622. In 2614, it may be determined whether the User field corresponds to a downlink user-specific PA, which may be performed by checking the PA Presence subfield of the EHT-SIG-A field and the PA Bitmap subfield of the EHT-SIG-B field. If it is determined that the User field corresponds to a downlink user-specific PA, processing may proceed to step 2616. If it is determined that the User field does not correspond to a downlink user-specific PA, processing may proceed to step 2618.In 2616, user-specific assignment information may be obtained, the RU information and the user-specific assignment information may be stored or updated, and a timer for the downlink user-specific PA may be started or reset. In step 2618, the user-specific assignment information may be obtained. In 2620, a transmission of the corresponding assignment may be received in the Data field. In 2622, a User field counter may be incremented by one. In 2624, it may be determined whether the User field counter is equal to the number of User fields in the User Specific fields. If it is determined that the User field counter is equal to the number of User fields in the User Specific fields, processing may proceed to step 2626. If it is determined that the User field counter is not equal to the number of User fields in the User Specific fields, processing may return to step 2612. In 2626, it may be determined whether any timers for the downlink user-specific PA are running. If it is determined that at least one timer for the downlink user-specific PA is running, processing may proceed to step 2628. If it is determined that no timers for downlink user-specific PAs are running, processing may end at step 2632. In 2628, it may be determined whether any of the RUs allocated for recurring transmissions match the latest stored RU information for any downlink user-specific PAs with running timers, and the RUs allocated for recurring transmissions may be determined by checking the Recurring Transmission Presence subfield of the EHT-SIG-A field and the Recurring Transmission Bitmap subfield of the EHT-SIG-B field. If it is determined that one of the RUs allocated for recurring transmissions matches the stored RU for a downlink user-specific PA with a running timer, processing may proceed to step 2630.If it is determined that none of the RUs assigned for repeated transmission match the stored RU information for any downlink user-specific PA with a running timer, the process may end at 2632. At 2630, the stored user-specific assignment information for the matching RUs is extracted, and the process may proceed to step 2620.

[0218] FIG. 27 illustrates a configuration of a communications device 2700, e.g., an access point (AP), according to various embodiments. Similar to the schematic example of a communications device shown in FIG. 3A, the communications device 2700 in the schematic example of FIG. 27 includes at least one wireless transmitter 2728, at least one wireless receiver 2704, multiple antennas 2702 (for simplicity, only one antenna is shown in FIG. 27), and circuitry 2730. The circuitry 2730 may include at least one controller 2712 for use in software- and hardware-assisted execution of the tasks the controller 2712 is designed to perform, including control of communications with downlink or uplink user-specific PAs. The circuitry 2730 may further include a receive signal processor 2706 and a transmit signal generator 2720. The controller 2712 may control the receive signal processor 2706 and the transmit signal generator 2720.

[0219] The receive signal processor 2706 may include a data demodulator / decoder 2710 that may demodulate and decode the data portion of the received signal. The receive signal processor 2706 may also include a control demodulator / decoder 2708 that may demodulate and decode the control signaling portion of the received signal (e.g., an EHT TB PPDU or a BlockAck frame).

[0220] The controller 2712 may include a control signal parser 2714 that may analyze the control signaling portion of the received signal. The controller 2712 may further include a scheduler 2716 that may determine RU information and user-specific assignment information for allocation. The scheduler 2716 may include persistent scheduling circuitry that determines identification information and user-specific resource assignment information associated with uplink user-specific PAs, as well as RU information and user-specific assignment information associated with downlink user-specific PAs.

[0221] The transmit signal generator 2720 may include an MPDU generator 2722, a control signaling generator 2724, and a PPDU generator 2726. The MPDU generator 2722 may generate MPDUs or A-MPDUs (Aggregated MPDUs), such as data frames and management frames carrying a PA Control subfield, an EHT Basic Trigger frame, a PA Trigger frame, or a PA Announcement frame. The control signaling generator 2724 may generate control signaling fields (e.g., EHT-SIG-A field and EHT-SIG-B field). The PPDU generator 1826 may generate PPDUs (e.g., EHT MU PPDUs).

[0222] FIG. 28 illustrates a configuration of a communications device 2800, e.g., a terminal, e.g., a station (STA), according to various embodiments. Similar to the schematic example of a communications device shown in FIG. 3A, the communications device 2800 in the schematic example of FIG. 28 includes at least one wireless transmitter 2830, at least one wireless receiver 2804, one or more antennas 2802 (for simplicity, only one antenna is shown in FIG. 28), and circuitry 2832. The circuitry 2832 may include at least one controller 2812 for use in software- and hardware-assisted execution of tasks that the controller 2812 is designed to perform, including control of communications with downlink or uplink user-specific PAs. The circuitry 2832 may further include a receive signal processor 2806 and a transmit signal generator 2822. The controller 2812 may control the receive signal processor 2806 and the transmit signal generator 2822.

[0223] The receive processor 2806 may include a data demodulation decoder 2810 and a control demodulation decoder 2808. The data demodulation decoder 2810 may demodulate and decode the data portion of the received signal according to the RU information and user-specific assignment information. The data portion of the received signal may include a Multi-STA BlockAck frame, a PA Announcement frame, an EHT Basic Trigger frame, a PA Trigger frame, or a frame carrying a PA Control subfield. The control demodulation decoder 2808 may demodulate and decode the control signaling portion of the received signal (e.g., the EHT-SIG-A and EHT-SIG-B fields of the EHT MU PPDU).

[0224] The controller 2812 may include a control signaling parser 2814 and a scheduler 2818. The control signaling parser 2814 may analyze the control signaling portion of the received signal and determine RU information and user-specific assignment information for the downlink user-specific PA. The control signaling parser 2814 may include a PA signaling parser 2816. The PA signaling parser 2816 may determine and store or update (e.g., in memory 2820) the RU information and user-specific assignment information for the downlink user-specific PA or extract (e.g., from memory 2820) the user-specific assignment information for the downlink user-specific PA. The PA signaling parser 2816 may also determine and store or update (e.g., in memory 2820) or extract (e.g., from memory 2820) the identification information and user-specific resource assignment information for the uplink user-specific PA.

[0225] The transmit signal generator 2822 may include a control signaling generator 2824, a PPDU generator 2826, and an MPDU generator 2828. The control signaling generator 2824 may generate a control signaling field (e.g., an EHT-SIG-A field). The PPDU generator 2826 may generate a PPDU (e.g., an EHT TB PPDU). The MPDU generator 2828 may generate an (A)-MPDU, e.g., a BlockAck frame.

[0226] As described above, the embodiments of the present disclosure provide an advanced communication system, communication method and communication device that enables user-specific PA in a MIMO WLAN network with very high throughput and improves physical layer throughput in the MIMO WLAN network.

[0227] The present disclosure may be realized by software, hardware, or software interfacing with hardware. Each functional block described in the above embodiments may be partially or entirely realized by an LSI such as an integrated circuit, and each process described in each embodiment may be partially or entirely controlled by the same LSI or a combination of LSIs. The LSI may be formed as an individual chip, or a single chip may be formed to include some or all of the functional blocks. The LSI may also include data input / output devices coupled thereto. Here, LSI may be referred to as an IC, system LSI, super LSI, or ultra LSI depending on the degree of integration. However, the technology for realizing an integrated circuit is not limited to LSI, and may be realized using dedicated circuits, general-purpose processors, or application-specific processors. Furthermore, a field programmable gate array (FPGA) may be used, in which the connections and settings of circuit cells arranged within the LSI can be reconfigured or a reconfigurable processor can be programmed after fabrication. The present disclosure may be realized as digital processing or analog processing. As a result of advances in semiconductor technology and other derivative technologies, if future integrated circuit technologies replace LSI, functional blocks can be integrated using future integrated circuit technologies. Biotechnology is also applicable.

[0228] The present disclosure may be implemented by any type of apparatus, device or system having communication capabilities, referred to as a communications apparatus.

[0229] Some non-limiting examples of such communication devices include telephones (e.g., mobile (cell) phones, smartphones), tablets, personal computers (PCs) (e.g., laptops, desktops, netbooks), cameras (e.g., digital still / video cameras), digital players (digital audio / video players), wearable devices (e.g., wearable cameras, smart watches, tracking devices), game consoles, digital book readers, telehealth / telemedicine (remote health and remote medical) devices, and vehicles (e.g., automobiles, airplanes, ships) that provide communication capabilities, and various combinations thereof.

[0230] Communications devices are not limited to being portable or mobile, but may include any type of equipment, device or system that is non-portable or fixed, such as smart home devices (e.g., appliances, lighting, smart meters, control panels), vending machines and any other "thing" in an "Internet of Things (IoT)" network.

[0231] Communications may include, for example, exchanging data via cellular systems, wireless LAN systems, satellite systems, and the like, as well as various combinations thereof.

[0232] A communications apparatus may include devices such as a controller or a sensor coupled to the communications device to perform the communications functions described in this disclosure. For example, a communications apparatus may include a controller or a sensor that generates control or data signals used by the communications device to perform the communications functions of the communications apparatus.

[0233] Communications equipment may also include infrastructure facilities such as base stations, access points, and any other equipment, device, or system that communicates with or controls equipment such as those in the above non-limiting examples.

[0234] Although some features of various embodiments have been described with reference to devices, it will be understood that corresponding features also apply to the methods of various embodiments, and vice versa.

[0235] It will be appreciated by those skilled in the art that numerous variations and / or modifications may be made to the present disclosure as set forth in the specific embodiments without departing from the spirit or scope of the disclosure as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

[0236] 1. A circuit that, during operation, generates a transmit signal including a common field, a user-specific field, and a data field, wherein the common field includes RU information for each of one or more allocations in the data field, and the user-specific field includes one or more user information, each indicating a user-specific allocation among the one or more allocations in the data field; a transmitter that, during operation, transmits the generated transmit signal; and The communication device, wherein the user-specific field is absent from at least one user information for a persistent assignment that includes repeated transmissions between the one or more assignments.

[0237] 2. The communications device of claim 1, wherein the transmission includes signaling to indicate the presence of at least one persistent assignment in the data field.

[0238] 3. The communications device of claim 1, wherein the common signal includes signaling for announcing at least one persistent assignment in the data field.

[0239] 4. The communications device of claim 1, wherein the transmission includes signaling to indicate the presence of at least one persistent assignment in the data field that includes a repeated transmission.

[0240] 5. The communications device of claim 1, wherein the common field includes signaling for informing at least one persistent assignment in the data field that includes repeated transmissions.

[0241] 6. The communications device of claim 1, wherein the persistent allocation exists for a period of time after transmission of the generated transmission signal.

[0242] 7. The communication device of claim 1, wherein the user-specific field is absent from at least one user information for a persistent assignment including an initial transmission, and the user information for the persistent assignment is included in a control frame previously transmitted by the communication device.

[0243] 8. The communication device of claim 7, wherein the persistent allocation exists for a period of time after transmission of the control frame.

[0244] 9. The communication device of claim 8, wherein the period is determined or signaled by signaling included in the control frame.

[0245] 10. A receiver that, during operation, receives a transmission signal including a common field, a user-specific field, and a data field, wherein the common field includes RU information for each of one or more allocations in the data field, and the user-specific field includes one or more user information, each indicating a user-specific allocation among the one or more allocations in the data field; circuitry for processing the received transmission signal during operation; and The communication device, wherein the user-specific field is absent from at least one user information for a persistent assignment that includes repeated transmissions between the one or more assignments.

[0246] 11. The communications device of claim 10, wherein the transmission includes signaling to indicate the presence of at least one persistent assignment in the data field.

[0247] 12. The communications device of claim 10, wherein the common signal includes signaling for announcing at least one persistent assignment in the data field.

[0248] 13. The communications device of claim 10, wherein the transmission includes signaling to indicate the presence of at least one persistent assignment in the data field that includes a repeated transmission.

[0249] 14. The communications device of claim 10, wherein the common field includes signaling for announcing at least one persistent assignment in the data field that includes a repeated transmission.

[0250] 15. The communications device of claim 10, wherein the persistent allocation exists for a period of time after transmission of the generated transmission signal.

[0251] 16. The communications device of claim 10, wherein the user-specific field is absent from at least one user information for a persistent assignment including an initial transmission, and the user information for the persistent assignment is included in a control frame previously transmitted by the communications device.

[0252] 17. The communications device of claim 16, wherein the persistent assignment exists for a period of time after receipt of the control frame.

[0253] 18. The communications device of claim 17, wherein the period is determined or signaled by signaling included in the control frame.

[0254] 19. Generating a transmission signal including a common field, a user-specific field, and a data field, wherein the common field includes RU information for each of one or more allocations in the data field, and the user-specific field includes one or more user information, each indicating a user-specific allocation among the one or more allocations in the data field; transmitting the generated transmission signal; and The method of communication, wherein the user-specific field is absent from at least one user information for a persistent assignment that includes repeated transmissions during the one or more assignments.

[0255] 20. Receiving a transmission signal including a common field, a user-specific field, and a data field, wherein the common field includes RU information for each of one or more allocations in the data field, and the user-specific field includes one or more user information, each indicating a user-specific allocation among the one or more allocations in the data field; The method of communication, wherein the user-specific field is absent from at least one user information for a persistent assignment that includes repeated transmissions during the one or more assignments.

[0256] 21. A circuit for generating, during operation, a transmission signal including at least one signal field content channel and a data field, each of the at least one signal field content channel including a resource unit (RU) allocation subfield consisting of N fields and a repeat transmission bitmap subfield consisting of N bitmaps, where N=1, 2, 4, or 8; a transmitter that, during operation, transmits the generated transmit signal; and A communications device, wherein each of the N fields of the RU allocation subfield indicates RU information for one or more allocations within the corresponding tone range in the data field, and the nth (n=1, 2, ..., N) bitmap of the repeated transmission bitmap subfield indicates whether each of the one or more allocations indicated by the nth field of the RU allocation subfield includes repeated transmission.

[0257] 22. The communication device of claim 21, wherein the nth (n=1, 2, ..., N) bitmap of the repeat transmission bitmap subfield is not present if the one or more allocations indicated by the nth field of the RU allocation subfield do not include the repeat transmission.

[0258] 23. The communication device of claim 21, wherein the transmission signal includes an N-bit repeat transmission presence subfield for each of the at least one signal field content channel, and the nth (n=1, 2, ..., N) bit of the repeat transmission presence subfield indicates the presence of the nth bitmap of the repeat transmission bitmap subfield in each of the at least one signal field content channel.

[0259] 24. The communications device of claim 21, wherein each of the at least one signal field content channel includes a persistent allocation bitmap subfield consisting of N bitmaps, and the bitmap of the nth persistent allocation bitmap subfield (n=1, 2, ..., N) indicates whether each of the one or more allocations indicated by the nth field of the RU allocation subfield is persistent or not.

[0260] 25. The communications device of claim 24, wherein the nth (n=1, 2, ..., N) bitmap of the persistent allocation bitmap subfield is not present if the one or more allocations indicated by the nth field of the RU allocation subfield are not persistent.

[0261] 26. The communications device of claim 24, wherein the transmitted signal includes an N-bit persistent allocation presence subfield for each of the at least one signal field content channel, and wherein the nth (n=1, 2, ..., N) bit of the N-bit persistent allocation presence subfield indicates the presence of the nth bitmap of the persistent allocation bitmap subfield in each of the at least one signal field content channel.

[0262] 27. The communication device of claim 21, wherein the RU allocation subfield and the repetitive transmission bitmap subfield are coded separately, and the size of the nth (n=1, 2, ..., N) bitmap of the repetitive transmission bitmap subfield depends on the number of the one or more allocations indicated by the nth field of the RU allocation subfield.

[0263] 28. The communication device of claim 21, wherein the RU allocation subfield and the repetitive transmission bitmap subfield are jointly coded, and the size of each bitmap in the repetitive transmission bitmap subfield depends on the maximum number of the one or more allocations that can be signaled by any of the RU allocation subfields.

[0264] 29. The communications device of claim 21, wherein the transmission signal includes signaling to indicate whether the RU allocation subfield and the repeated transmission bitmap subfield of each of the at least one signal field content channel are coded separately or jointly.

[0265] 30. The communications device of claim 21, wherein each of the at least one signal field content channel includes an M-bit center 26-tone RU subfield, where M=1 for CBW=80, 80+80, or 160 MHz, and M=2 for CBW=160+160, or 320 MHz, and each bit of the M-bit center 26-tone RU subfield indicates whether a corresponding center 26-tone RU is assigned or not.

[0266] 31. The communications device of claim 30, wherein when M=1, the last bitmap of the repeat transmission bitmap subfield indicates whether the allocation indicated by the M-bit center 26-tone RU subfield includes repeat transmission.

[0267] 32. The communication device of claim 30, wherein when M=2, the fourth bitmap of the repeat transmission bitmap subfield indicates whether the allocation indicated by the first bit of the M-bit center 26-tone RU subfield includes repeat transmission, and the last bitmap of the repeat transmission bitmap subfield indicates whether the allocation indicated by the second bit of the M-bit center 26-tone RU subfield includes repeat transmission.

[0268] 33. The communications device of claim 21, wherein each of the at least one signal field content channel is encoded on a respective L*20 MHz with L=1 or 2, and the number of the at least one signal field content channel depends on the channel bandwidth (CBW) and the value of L.

[0269] 34. The communications device of claim 33, wherein the transmission signal includes signaling for reporting the value of L.

[0270] 35. Generating a transmission signal including at least one signal field content channel and a data field, each of the at least one signal field content channel including a Resource Unit (RU) allocation subfield consisting of N fields and a repeated transmission bitmap subfield consisting of N bitmaps, where N=1, 2, 4, or 8; transmitting the generated transmission signal; and A communication method in which each of the N fields of the RU allocation subfields indicates RU information for one or more allocations within a corresponding tone range in the data field, and an nth (n=1, 2, ..., N) bitmap of the repeated transmission bitmap subfield indicates whether each of the one or more allocations indicated by the nth field of the RU allocation subfield includes repeated transmission.

[0271] 36. A circuit for generating a frame including identification information that identifies an uplink persistent assignment (PA) during operation; a transmitter that, during operation, transmits the generated frames; A communication device having:

[0272] 37. The communications device of claim 36, wherein the identification information is a PA identifier (PAID) of the uplink PA.

[0273] 38. The communications device of claim 36, wherein the identification information is RU (Resource Unit) allocation information for the uplink PA.

[0274] 39. The communications device of claim 36, wherein the identification information is included in a frame body of the frame to request transmission of the uplink PA, and the frame is devoid of user-specific resource allocation information for the uplink PA.

[0275] 40. The communications device of claim 36, wherein the identification information is included in a MAC header of the frame to request transmission of the uplink PA, and the frame is devoid of user-specific resource allocation information for the uplink PA.

[0276] 41. The communications device of claim 36, wherein the identification information and user-specific resource allocation information are included in a frame body of the frame to identify the uplink PA.

[0277] 42. The communications device of claim 36, wherein the identification information and user-specific resource allocation information are included in a frame body of the frame to request an initial transmission of the uplink PA.

[0278] 43. Generating a frame including identification information identifying an uplink persistent assignment (PA); transmitting the generated frame; A communication method comprising:

[0279] 44. The communications method of claim 43, wherein the identification information is a PA identifier (PAID) of the uplink PA.

[0280] 45. The communications method of claim 43, wherein the identification information is Resource User (RU) allocation information for the uplink PA.

[0281] 46. ​​The communication method of claim 43, wherein the identification information is included in a frame body of the frame to request transmission of the uplink PA, and the frame is devoid of user-specific resource allocation information for the uplink PA.

[0282] 47. The communication method of claim 43, wherein the identification information is included in a MAC header of the frame to request transmission of the uplink PA, and the frame is devoid of user-specific resource allocation information for the uplink PA.

[0283] 48. The communications method of claim 43, wherein the identification information and user-specific resource allocation information are included in a frame body of the frame to identify the uplink PA.

[0284] 49. The communications method of claim 43, wherein the identification information and user-specific resource allocation information are included in a frame body of the frame to identify the uplink PA.

[0285] 50. During operation, generate a first transmit signal including user information for a plurality of users of a downlink MU-MIMO allocation, each indicating a user-specific allocation; a circuit for further generating a second transmission signal including a common field, a user-specific field, and a data field, the data field including a transmission of the downlink MU-MIMO allocation; a transmitter that, during operation, transmits the first transmission signal and the second transmission signal; and The communication device, wherein the user-specific allocation of downlink MU-MIMO allocation is determined to be persistent or not.

[0286] 51. The communications device of claim 50, wherein a user-specific persistent allocation of the downlink MU-MIMO allocation in the data field of the second transmission is signaled by the user information in the first transmission.

[0287] 52. The communications device of claim 50, wherein when the data field of the second transmission signal includes a repeated transmission of a user-specific persistent assignment of the MU-MIMO assignment, the user-specific field is absent from user information for the user-specific persistent assignment.

[0288] 53. The communications device of claim 50, wherein the common field of the second transmission includes signaling for indicating at least one user-specific persistent assignment in the data field of the second transmission.

[0289] 54. The communications device of claim 50, wherein the common field of the second transmission includes signaling for indicating at least one user-specific persistent assignment in the data field of the second transmission including repeated transmissions.

[0290] 55. The communications device of claim 50, wherein the user-specific persistent assignment exists for a period of time after transmission of the first transmission.

[0291] 56. The communications device of claim 55, wherein the period is determined or signaled by signaling included in the first transmission signal.

[0292] 57. Generating a first transmission signal including user information for a plurality of users of a downlink MU-MIMO allocation, each user indicating a user-specific allocation; generating a second transmission signal including a common field, a user-specific field, and a data field, the data field including the transmission of the downlink MU-MIMO allocation; transmitting the first transmission signal and the second transmission signal; and A method of communication, wherein the user-specific allocation of the downlink MU-MIMO allocation is determined to be persistent or not.

[0293] 58. The communications method of claim 57, wherein a user-specific persistent allocation of the downlink MU-MIMO allocation in the data field of the second transmission is signaled by the user information in the first transmission.

[0294] 59. The communications method of claim 57, wherein when the data field of the second transmission signal includes a repeated transmission of a user-specific persistent assignment of the downlink MU-MIMO assignment, the user-specific field is empty of user information of the user-specific persistent assignment.

[0295] 60. The communications method of claim 57, wherein the common field of the second transmission includes signaling for indicating at least one user-specific persistent assignment in the data field of the second transmission.

[0296] 61. The communications method of claim 57, wherein the common field of the second transmission includes signaling for indicating at least one user-specific persistent assignment in the data field of the second transmission including repeated transmissions.

[0297] 62. The communications method of claim 57, wherein the user-specific persistent assignment exists for a period of time after transmission of the first transmission.

[0298] 63. A communications method according to claim 62, wherein the period is determined or signalled by signalling included in the first transmission signal.

Claims

1. a first communication device, a receiver for receiving a trigger frame from a second communication device within a transmission opportunity (TXOP); a transmitter for transmitting two or more physical layer protocol data units (PPDUs) within the TXOP; the trigger frame includes a USER INFO field for the first communication device; the USER INFO field includes a RESOURCE UNIT (RU) ALLOCATION subfield; The RU ALLOCATION subfield indicates information of frequency resources on which the two or more PPDUs are transmitted, After the trigger frame is transmitted, no other trigger frame including a USER INFO field for the first communication device is transmitted within the TXOP. A first communication device.

2. the trigger frame is transmitted to the first communication device and the third communication device within the TXOP; Another PPDU is transmitted from the third communication device within the TXOP. The first communication device according to claim 1 .

3. the receiver receives block acknowledgment information for the two or more PPDUs within the TXOP. The first communication device according to claim 1 .

4. The two or more PPDUs do not overlap in time. The first communication device according to claim 1 .

5. a first PPDU transmitted first among the two or more PPDUs is a response to the trigger frame, and one or more PPDUs other than the first PPDU among the two or more PPDUs are not responses to the trigger frame; The first communication device according to claim 1 .

6. the two or more PPDUs are transmitted to the second communication device. The first communication device according to claim 1 .

7. the first communication device is a non-access point station and the second communication device is an access point; The first communication device according to claim 1 .

8. When the first communication device receives the trigger frame, the first communication device starts or resets a timer for the TXOP. The first communication device according to claim 1 .

9. The trigger frame is included in an EXTREMELY HIGH THROUGHPUT (EHT) multi-user (MU) PPDU. The first communication device according to claim 1 .

10. The trigger frame is used to set information related to the TXOP included in the two or more PPDUs. The first communication device according to claim 1 .

11. the first communication device stores information about the frequency resource included in the trigger frame, and generates a second PPDU to be transmitted second among the two or more PPDUs based on the stored information about the frequency resource; The first communication device according to claim 1 .

12. The first communication device is identified by a value of the AID12 subfield of the trigger frame. The first communication device according to claim 1 .

13. 1. A communication method for a first communication device, comprising: receiving a trigger frame from a second communication device within a transmit opportunity (TXOP); transmitting two or more physical layer protocol data units (PPDUs) within the TXOP; the trigger frame includes a USER INFO field for the first communication device; the USER INFO field includes a RESOURCE UNIT (RU) ALLOCATION subfield; The RU ALLOCATION subfield indicates information of frequency resources on which the two or more PPDUs are transmitted, After the trigger frame is transmitted, no other trigger frame including a USER INFO field for the first communication device is transmitted within the TXOP. Communication method.

14. 1. An integrated circuit for a first communication device, comprising: receiving a trigger frame from a second communication device within a transmit opportunity (TXOP); transmitting two or more physical layer protocol data units (PPDUs) within the TXOP; the trigger frame includes a USER INFO field for the first communication device; the USER INFO field includes a RESOURCE UNIT (RU) ALLOCATION subfield; The RU ALLOCATION subfield indicates information of frequency resources on which the two or more PPDUs are transmitted, After the trigger frame is transmitted, no other trigger frame including a USER INFO field for the first communication device is transmitted within the TXOP. Integrated circuit.

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