Patent ID: 12206471

DETAILED DESCRIPTION

To assist in understanding the present disclosure, an example system supporting wireless communications over air interfaces is first described.

FIG.1Ais a schematic diagram of an example system100in which methods described herein may be implemented. The system100shown inFIG.1Amay support a wireless local area network (WLAN) including an access point (AP)102and multiple stations (STAs)104within coverage of the AP102. In the example shown, there is only one STA104and one AP102, however there may be multiple STAs104and/or multiple APs102. Each STA104may be any suitable device capable of wireless communication, including mobile or stationary devices such as smartphones, laptops, mobile phones or tablet devices, for example, and the STAs104need not be the same as each other. The STAs104may also be referred to as terminals, user devices, user equipment (UE) or clients, for example. The AP102may be also referred to as a base station. The AP102may be implemented as a router, for example. The STA104may access a network106via the AP102.

The system100may support communication between the AP102and each STA104, as well as communication directly between STAs104(also referred to as device-to-device communication). Using multiple antennas, the AP102may carry out multi-user transmissions (e.g., transmissions from the AP102to multiple STAs104simultaneously) by using the spatial reuse technique of multi-user multiple-input multiple-output (MU-MIMO). For simplicity, examples described herein may refer to wireless communications over air interfaces between a STA104and an AP102, however it should be understood that the present disclosure may be equally applicable to wireless communications over air interfaces between two STAs104, multi-user communications (e.g., between an AP102and multiple STAs104), or any other wireless communications over air interfaces.

FIG.1Bis a block diagram illustrating an example processing unit150, which may be used to implement the methods and systems disclosed herein, for example the AP102and/or one or more of the STAs104. Other processing units suitable for implementing the present disclosure may be used, which may include components different from those discussed below. AlthoughFIG.1Bshows a single instance of each component, there may be multiple instances of each component in the processing unit150.

The processing unit150includes one or more processing devices152, such as a processor, a microprocessor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a dedicated logic circuitry, or combinations thereof. The processing unit150may also include one or more input/output (I/O) interfaces154, which may enable interfacing with one or more appropriate input devices164and/or output devices166. The processing unit150includes one or more network interfaces156for wired or wireless communication with the network106(e.g., an intranet, the Internet, a P2P network, a WAN, a LAN, and/or a Radio Access Network (RAN)). The network interface(s)156may include wired links (e.g., Ethernet cable) and/or wireless links for intra-network and/or inter-network communications. The network interface(s)156may provide wireless communication via one or more transmitters/receivers or transceiver antennas168, for example. The antennas168may act together as an antenna array, in which case each antenna168may be referred to as an antenna element or radiating element of the antenna array. There may be a plurality of such antenna arrays. The processing unit150may also include one or more storage units158, which may include a mass storage unit such as a solid state drive, a hard disk drive, a magnetic disk drive and/or an optical disk drive.

The processing unit150may include one or more memories160, which may include a volatile or non-volatile memory (e.g., a flash memory, a random access memory (RAM), and/or a read-only memory (ROM)). The non-transitory memory(ies)160may store instructions (e.g., in the form of software modules) for execution by the processing device(s)152, such as to carry out the methods described in the present disclosure. For example, instructions for implementing a logical layer for supporting MLA (as described further below) may be stored in the memory(ies)160.

The memory(ies)160may include other software instructions, such as for implementing an operating system and other applications/functions. In some examples, one or more data sets and/or module(s) may be provided by an external memory (e.g., an external drive in wired or wireless communication with the processing unit150) or may be provided by a transitory or non-transitory computer-readable medium. Examples of non-transitory computer readable media include a RAM, a ROM, an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a flash memory, a CD-ROM, or other portable memory storage.

There may be a bus162providing communication among components of the processing unit150, including the processing device(s)152, I/O interface(s)154, network interface(s)156, storage unit(s)158and/or memory(ies)160. The bus162may be any suitable bus architecture including, for example, a memory bus, a peripheral bus or a video bus.

InFIG.1B, the input device(s)164(e.g., a keyboard, a mouse, a microphone, a touchscreen, and/or a keypad) and output device(s)166(e.g., a display, a speaker and/or a printer) are shown as external to the processing unit150. In other examples, one or more of the input device(s)164and/or the output device(s)166may be included as a component of the processing unit150. In other examples, there may not be any input device(s)164and output device(s)166, in which case the I/O interface(s)154may not be needed.

The AP102and STAs104may each include multiple antenna elements168forming antenna arrays, and may carry out appropriate beamforming and beam steering controls (e.g., using beamsteering circuits and/or beamsteering control modules implemented by the processing device152and processing unit150), in order to carry out wireless communication over air interfaces.

FIG.2depicts the format of a medium access control (MAC) frame format of 802.11. The frame format includes a MAC header200, frame body202and frame check sequence204. Among other fields, the MAC header200includes a high throughput (HT) control field206.

The HT control field206is present in a Control Wrapper frame, QoS Data frame, and QoS Null frames, and is also present in management frames as determined by the +HTC subfield of the frame control field in MAC header200. The format of the HT control field is defined as shown inFIG.3Afor high throughput (HT), very high throughput (VHT), and high efficiency (HE) variants. For the HT variant, the fields include HT Control Middle, AC (access control) Constraint, RDG (Reverse Direction Grant)/More PPDU (PHY Protocol Data Unit). For the VHT variant, the fields include VHT Control Middle, AC Constraint, RDG/More PPDU. For the HE variant, the fields include A-Control.

The HT Control field for the VHT and HE variants carry link adaptation (LA) parameters. For the HE variant, these are carried in the A-Control subfield, as detailed below.

The A-Control subfield is 30 bits long. The format of the A-Control subfield is shown inFIG.3B, and includes a 4-bit control ID, and maximum 26-bit control information.

FIG.4is a table showing the meaning of the control ID subfield value defined in 802.11be D1.0. The control ID value is indicated in column400, corresponding meaning in column402, length of control information subfield in column404, and content of the subfield in column406. Different control ID values are assigned to indicate11different control information subfields.

The remaining 26 bits beyond the 4-bit control ID are used for the control information in the A-Control subfield. As can be seen from the length of control information indicated in column404, some control IDs do not fully utilize all 26 bits of the control information subfield, and in this case, the remainder of the control information subfield is padded with zeros. The control ID value of “2” with 4-bit binary representation “0010” indicates a control frame contains an HLA control subfield. In this type of control field, the full 26 bits are allocated for control information without zero padding.

FIG.5depicts the HLA control subfield format specified in 802.11ax, which shows how 26 bits are utilized for the indication of HE link adaptation (HLA) parameters. Among other parameters, the HLA parameters include one parameter to indicate a number of spatial streams, namely parameter Nss500and one parameter to indicate modulation and coding scheme (MCS), namely parameter HE-MCS502.

The 30-bit A-Control subfield of the HT Control field is not large enough to carry additional LA parameters for EHT such as separate Nss parameters for single user-multiple input multiple output (SU-MIMO) and multi-user MIMO (MU-MIMO), and separate MCS parameters for SU-MIMO and MU-MIMO.

EHT Link Adaptation (EHT LA) Using Two Control ID Values in A-Control Subfield of the HE Variant HT Control Field—First Method

In accordance with a first embodiment, as shown in Table 1 below, two reserved Control ID values in A-Control subfield are used to indicate two separate Control Information subfields for EHT LA related to SU MIMO and MU MIMO respectively. In the example shown in the table, Control IDs 11 and 12 are used for this purpose, but more generally, any available reserved control IDs can be used, for example, two control IDs from the currently unused set which includes control IDs 9, and 11 to 14. Control Information subfield for EHT LA includes 26 bits for either SU-MIMO or MU-MIMO configuration.

TABLE 1Control ID and EHT LA in A-Control field in Embodiment 1Length ofthe ControlContent of theControlInformationControlIDsubfieldInformationValueMeaning(bits)subfield...2HE link adaptation26See 9.2.4.6a.3(HLA)(HLA control) in802.11ax-2021...11EHT Link Adaptation26See below(EHT LA) - SU MIMO12EHT Link Adaptation26See below(EHT LA) - MU MIMO
Control Information Subfield in EHT Link Adaptation (EHT LA)

An example of the content of Control Information subfield in EHT LA SU MIMO and in EHT LA MU MIMO that might be used for this embodiment is illustrated inFIGS.6and7respectively. However, it should be understood that this is just an example, and that different LA parameters for one or both of SU MIMO or MU MIMO may be used.

An example set of definitions for the EHT LA parameters in Control Information subfield included in the examples ofFIGS.6and7is provided below for EHT LA in SU-MIMO or MU-MIMO.

Unsolicited modulation and coding scheme (MCS) feedback (MFB) (Unsolicited MFB indicator):Set to 1 if EHT LA Control is an unsolicited MFB.Set to 0 if EHT LA Control is an EHT LA feedback request indicator (MRQ) or a solicited MFB.

MRQ (EHT LA feedback request indicator):Set to 1 and set Unsolicited MFB to 0 to request an EHT LA feedback.Set to 0 and set Unsolicited MFB to 0 to respond to an EHT LA request.If the Unsolicited MFB is 1, the MRQ is reserved.

NSS for SU-MIMO (Recommended number of spatial streams for SU-MIMO):If the Unsolicited MFB is 1 and the UL EHT TB PPDU MFB (defined below) is 0 or if the Unsolicited MFB is 0 and the MRQ is 0, the NSS for SU-MIMO subfield indicates the recommended number of spatial streams to the PPDU sent to the STA, Nss,su-mimo, and is set to Nss,su-mimo−1. The range of Nss,su-mimois 1 to 16.If the Unsolicited MFB is 1 and the UL EHT TB PPDU MFB is 1, the NSS subfield indicates the recommended number of spatial streams to the EHT TB PPDU sent from the STA, Nss,su-mimo, and is set to Nss,su-mimo−1.Otherwise, this subfield is reserved.

NSS for MU-MIMO (Recommended number of spatial streams for MU-MIMO):If the Unsolicited MFB is 1 and the UL EHT TB PPDU MFB is 0 or if the Unsolicited MFB is 0 and the MRQ is 0, the NSS for MU-MIMO subfield indicates the recommended number of spatial streams to the PPDU sent to the STA, Nss,mu-mimo, and is set to Nss,mu-mimo−1. The range of Nss,mu-mimois 1 to 4.If the Unsolicited MFB is 1 and the UL EHT TB PPDU MFB is 1, the NSS subfield indicates the recommended number of spatial streams to the EHT TB PPDU sent from the STA, Nss,mu-mimo, and is set to Nss,mu-mimo−1.Otherwise, this subfield is reserved.

EHT-MCS for SU-MIMO (Recommended EHT-MCS for SU-MIMO):If the Unsolicited MFB subfield is 1 and the UL EHT TB PPDU MFB subfield is 0 or if the Unsolicited MFB is 0 and the MRQ is 0, the EHT-MCS for SU-MIMO indicates the recommended EHT-MCS of the PPDU sent to the STA with SU-MIMO, and is set to the EHT-MCS index.If the Unsolicited MFB is 1 and the UL EHT TB PPDU MFB subfield is 1, the EHT-MCS for SU MIMO indicates the recommended EHT-MCS of the EHT TB PPDU sent from the STA in SU-MIMO, and is set to the EHT-MCS index.Otherwise, this subfield is reserved.

EHT-MCS for MU-MIMO (Recommended EHT-MCS for MU-MIMO):If the Unsolicited MFB subfield is 1 and the UL EHT TB PPDU MFB subfield is 0 or if the Unsolicited MFB is 0 and the MRQ is 0, the EHT-MCS for MU-MIMO indicates the recommended EHT-MCS of the PPDU sent to the STA with MU-MIMO, and is set to the EHT-MCS index.If the Unsolicited MFB is 1 and the UL EHT TB PPDU MFB subfield is 1, the EHT-MCS for MU MIMO indicates the recommended EHT-MCS of the EHT TB PPDU sent from the STA in MU-MIMO, and is set to the EHT-MCS index.Otherwise, this subfield is reserved.

RU Allocation (resource unit (RU)/multi-unit resource unit (MRU) of the recommended EHT-MCS/RU/MRU):If the Unsolicited MFB is 1 and the UL EHT TB PPDU MFB is 0, the RU Allocation subfield indicates the RU/MRU for which the recommended EHT-MCS applies to the PPDU sent to the STA.If the Unsolicited MFB is 0 and the MRQ is 1, the RU Allocation subfield indicates the RU/MRU requested by the MFB requester to get feedback.The RU Allocation is interpreted with the BW to specify the RU/MRU.If the Unsolicited MFB is 1 and the UL EHT TB PPDU MFB is 1, the RU Allocation indicates the RU/MRU for which the recommended EHT-MCS applies to the EHT TB PPDU sent from the STA and that the actual allocation of the RU/MRU can be ignored by the recipient.Otherwise, this subfield is reserved.

BW (Bandwidth of the recommended EHT-MCS/Bandwidth specified by MFB requester to get feedback):If the Unsolicited MFB is 1 and the UL EHT TB PPDU MFB is 0, the BW indicates the bandwidth for which the recommended EHT-MCS applies to the PPDU sent to the STA.If the Unsolicited MFB is 1 and the UL EHT TB PPDU MFB is 1, the BW indicates the bandwidth for which the recommended EHT-MCS applies to the EHT TB PPDU sent from the STA.If the Unsolicited MFB is 0 and the MRQ is 1, the BW indicates the bandwidth requested by the MFB requester to get feedback.Set to 0 for 20 MHz. Set to 1 for 40 MHz. Set to 2 for 80 MHz. Set to 3 for 160 MHz. Set to 4 for 320-1 MHz. Set to 5 for 320-2 MHz.Otherwise, this subfield is reserved.

MSI/Partial PPDU Parameters (Partial parameters of the measured PPDU/MRQ sequence identifier):If the Unsolicited MFB subfield is 0 and the MRQ subfield is 1, the MSI/Partial PPDU Parameters subfield contains a sequence number in the range 0 to 3 that identifies the specific EHT-MCS feedback request.If the Unsolicited MFB subfield is 0 and the MRQ subfield is 0, the MSI/Partial PPDU Parameters subfield contains a sequence number in the range 0 to 3 that responds to the specific solicited EHT-MCS feedback request.If the Unsolicited MFB subfield is 1, the MSI/Partial PPDU Parameters subfield contains the PPDU Format (1 bit for indication of EHT MU PPDU or EHT TB PPDU) and Coding Type (1 bit for indication of BCC or LDPC) subfields.

Tx Beamforming (Transmission type of the measured PPDU):If the Unsolicited MFB subfield is 1 and the UL EHT TB PPDU MFB subfield is 0, then the Tx Beamforming subfield indicates whether or not the PPDU from which the unsolicited MFB was estimated is beamformed.Set to 0 for non-beamformed PPDUSet to 1 for beamformed PPDUOtherwise, this subfield is reserved.

UL EHT TB PPDU MFB (UL EHT trigger-based (TB) PPDU MFB indication):If the Unsolicited MFB subfield is 1, a value of 1 in this subfield indicates that the NSS, EHT-MCS, BW and RU Allocation fields represent the recommended MFB for the EHT TB PPDU sent from the STA.Otherwise, this subfield is reserved.

The advantages of the first embodiment include maintaining the A-Control format and the definition for subfields in A-Control subfield for HE unchanged by using two reserved control ID values.

EHT Link Adaptation (EHT LA) Using Two Control ID Values in A-Control Subfield of the HE Variant HT Control Field—Second Method

In accordance with a second embodiment, Control Information subfields in EHT LA field for SU-MIMO and MU-MIMO are indicated by the Control ID value equal to 2 (for HLA in 802.11ax) and by a reserved Control ID value (e.g., 11) in A-Control subfield, respectively. Control Information subfield for EHT LA includes 26 bits for either SU-MIMO or MU-MIMO configuration.

In this case, control ID 2 is used for both HLA and EHT LA for SU-MIMO. The transmitter and the receiver will distinguish between these two cases on some other basis, for example the length field in a legacy PHY header at the physical (PHY) layer. If this distinction can be made at the PHY layer, then the receiver will know by the time MAC layer processing is to be performed. More specifically, at the PHY layer, the transmitter and the receiver can determine whether the frame is HLA or EHT. In the example below, when TXVECTOR parameter FORMAT (a specific example of a PHY layer parameter) indicates an HE PPDU, this means the frame is HLA and control ID 2 is interpreted to indicate HLA LA parameters. On the other hand, when TXVECTOR parameter FORMAT indicates an EHT PPDU, this means the frame is EHT, and control ID 2 is interpreted to EHT LA for SU MIMO. More generally, an indication can be communicated at the physical layer that the MAC frame is a frame of a next generation protocol of a High Efficiency (HE) protocol, EHT being a specific example.

TABLE 2Control ID and EHT LA in A-Control field in Second EmbodimentLength ofthe ControlContent of theControlInformationControlIDsubfieldInformationValueMeaning(bits)subfield2HE link adaptation26when TXVECTOR(HLA)/EHT LinkparameterAdaptation (EHT LA) -FORMAT indicatesSU MIMOan HE PPDU, useHLAwhenTXVECTORparameterFORMAT indicatesan EHT PPDU,use EHT LA - SUMIMO (seebelow)11EHT Link Adaptation26See below(EHT LA) - MU MIMO

A specific example of the format of the Control Information subfield in EHT Link Adaptation (EHT LA) is one that is identical to the example for the first embodiment detailed above, but other formats may alternatively be used. Example definitions of EHT LA parameters in the Control Information subfield are as described for the first embodiment above.

An advantage of the second embodiment includes maintaining the A-Control format unchanged and using one existing Control ID for HLA and one reserved Control ID for indication of EHT LA.

It can be seen that the first and second embodiments share the feature that two control IDs are used for EHT LA; one is used for SU-MIMO (this either being 2, or a reserved control ID) and another is used for MU-MIMO (this being a reserved control ID). A flowchart of a method that encompasses the first and second embodiment is depicted inFIG.8. The method begins in block800with communicating, by a wireless communication device, a medium access control (MAC) frame comprising a MAC header, frame body and frame check sequence. The MAC header contains a high throughput (HT) control sub-field, the HT control sub-field containing a control ID value and control information as indicated at802. When the control ID value is set to a first value, the control information is extremely high throughput (EHT) link adaptation parameters for EHT communication for single user-multiple input multiple output (SU-MIMO), as indicated at804. When the control ID value is set to a second value, the control information is EHT link adaptation parameters for EHT communication for multi-user-multiple input multiple output (MU-MIMO), as indicated at806.

In some embodiments, the first control ID is one of 9, 11, 12, 13, 14, and the second control ID is a different one of 9, 11, 12, 13, 14. In some embodiments, the first control ID is 2, and the second is one of 9, 11, 12, 13, 14. When the first value is 2, the method further involves communicating an indication at the physical layer that the MAC frame is a frame of a next generation protocol of High Efficiency (HE) protocol.

InFIG.8, the communicating can involve receiving by an access point. Alternatively communicating can involve transmitting by an access point. The communicating can involve receiving by a non-AP station. Alternatively communicating can involve transmitting by a non-AP station.

EHT Link Adaptation (EHT LA) Using One Control ID Value in A-Control Subfield of the HE Variant HT Control Field—First Method

In a third embodiment, one reserved Control ID value in A-Control subfield is used to indicate one Control Information subfield carrying EHT LA parameters related to SU-MIMO or MU-MIMO configuration. The Control Information subfield for EHT LA includes 26 bits. Included in the 26 bits is an SU/MU-MIMO indication (for example a single SU/MU-MIMO indication bit) that is used to signal whether the EHT LA parameters carried in the Control Information subfield are related to SU-MIMO or MU-MIMO. The position of the SU/MU-MIMO indication can vary depending on other factors. A specific example is provided below where this is the case. Control ID meanings for this example are depicted in Table 3 below, where control ID 2 is used as before for HE link adaptation, and a reserved control ID (11 in the example) is used for EHT link adaptation.

TABLE 3Control ID and EHT LA in A-Control field in Third EmbodimentLength ofthe ControlContent of theControlInformationControlIDsubfieldInformationValueMeaning(bits)subfield...2HE link adaptation26See 9.2.4.6a.3(HLA)(HLA control) in802.11ax-2021...11EHT Link Adaptation26See below(EHT LA)

A specific example of the content of Control Information subfield in EHT LA for SU-MIMO or MU-MIMO is illustrated inFIG.9.

FIGS.10A and10Bshow a detailed breakdown of the RU Allocation/(Partial RU Allocation, SU/MU-MIMO) subfield. The content for the case where the recommended BW=20 MHz, is depicted inFIG.10A. In this case, the RU allocation/(partial RU allocation, SU/MU-MIMO indication) subfield contains a partial RU allocation and the SU/MU-MIMO indication, using 8 bits and one bit in the illustrated example.

The content for the case where the recommended BW>20 MHz, is depicted inFIG.10B. In this case, the RU allocation/(partial RU allocation, SU/MI-MIMO indication) subfield contains only RU allocation, 9 bits in the illustrated example.

FIGS.11A,11B and11Cshow a detailed breakdown of the MSI/(PPDU Format, Coding Type)/(PPDU Format, SU/MU-MIMO) subfield, which varies as a function of unsolicited MFB subfield and the recommended BW subfield.

The content for the case where the unsolicited MFB subfield is 0 is depicted inFIG.11A. In this case, the MSI/(PPDU Format, Coding Type)/(PPDU Format, SU/MU-MIMO) subfield simply contains MSI. Note that in this case, there is no need to indicate SU-MIMO or MU-MIMO configuration since a solicited MFB implies a STA knows the feedback type the requester requires with the identified specific HE-MCS feedback request or that responds to the specific solicited HE-MCS feedback request.

The content for the case where the Unsolicited MFB subfield is 1 and the recommended BW=20 MHz is depicted at inFIG.11B. In this case the subfield contains PPDU format and coding type, using one bit each in the illustrated example.

The content for the case where the Unsolicited MFB subfield is 1 and the recommended BW>20 MHz is depicted atFIG.11C. In this case, the subfield contains PPDU format and the SU/MU-MIMO indicator.

A specific example definition of the EHT LA parameters in Control Information subfield for this embodiment is provided below.

Unsolicited MFB (Unsolicited MFB indicator):Set to 1 if EHT LA Control is an unsolicited MFB.Set to 0 if EHT LA Control is an MRQ or a solicited MFB.

MRQ (EHT LA feedback request indicator):Set to 1 and set Unsolicited MFB to 0 to request an EHT LA feedback.Set to 0 and set Unsolicited MFB to 0 to respond to an EHT LA request.If the Unsolicited MFB is 1, the MRQ is reserved.

NSS (Recommended number of spatial stream for SU-MIMO or MU-MIMO)

If the Unsolicited MFB is 1 and the UL EHT TB PPDU MFB is 0, and

1) if SU/MU-MIMO subfield indicates SU-MIMO, the NSS subfield indicates the recommended number of spatial streams to the PPDU sent to the STA, Nss,su-mimo, and is set to Nss,su-mimo−1. The range of Nss,su-mimois 1 to 16;2) if SU/MU-MIMO subfield indicates MU-MIMO, the NSS subfield indicates the recommended number of spatial streams to the PPDU sent to the STA, Nss,mu-mimo, and is set to Nss,mu-mimo−1. The range of Nss,mu-mimois 1 to 4.
If the Unsolicited MFB is 1 and the UL EHT TB PPDU MFB is 1, and1) If SU/MU-MIMO subfield indicates SU-MIMO, the NSS subfield indicates the recommended number of spatial streams to the EHT TB PPDU sent from the STA, Nss,su-mimo, and is set to Nss,su-mimo−1;2) If SU/MU-MIMO subfield indicates MU-MIMO, the NSS subfield indicates the recommended number of spatial streams to the EHT TB PPDU sent from the STA, Nss,mu-mimo, and is set to Nss,mu-mimo−1;if the Unsolicited MFB is 0 and the MRQ is 0, the NSS subfield indicates the recommended number of spatial streams to the PPDU sent to the STA for either SU-MIMO or MU-MIMO that can be identified by MSI.Otherwise, this subfield is reserved.

EHT-MCS (Recommended EHT-MCS for SU-MIMO or MU-MIMO)

If the Unsolicited MFB subfield is 1 and the UL EHT TB PPDU MFB subfield is 0, and1) if SU/MU-MIMO subfield indicates SU-MIMO, the EHT-MCS subfield indicates the recommended EHT-MCS of the PPDU sent to the STA with SU-MIMO, and is set to the EHT-MCS index;2) if SU/MU-MIMO subfield indicates MU-MIMO, the EHT-MCS subfield indicates the recommended EHT-MCS of the PPDU sent to the STA with MU-MIMO, and is set to the EHT-MCS index;

If the Unsolicited MFB is 1 and the UL EHT TB PPDU MFB subfield is 1, and1) if SU/MU-MIMO subfield indicates SU-MIMO, the EHT-MCS subfield indicates the recommended EHT-MCS of the EHT TB PPDU sent from the STA in SU-MIMO, and is set to the EHT-MCS index;2) if SU/MU-MIMO subfield indicates MU-MIMO, the EHT-MCS subfield indicates the recommended EHT-MCS of the EHT TB PPDU sent from the STA in MU-MIMO, and is set to the EHT-MCS index;if the Unsolicited MFB is 0 and the MRQ is 0, the EHT-MCS subfield indicates the recommended EHT-MCS to the PPDU sent to the STA for either SU-MIMO or MU-MIMO that can be identified by MSI.Otherwise, this subfield is reserved.

RU Allocation/(Partial RU Allocation, SU/MU-MIMO) (RU of the recommended EHT-MCS/RU/MRU specified by MFB requester to get feedback and SU/MU-MIMO type)

If the BW subfield is set to 0 (indicating the PPDU bandwidth of recommended EHT-MCS/RU/MRU to be 20 MHz), this subfield contains Partial RU Allocation and SU/MU-MIMO subfields that include 8 bits and 1 bit respectively as described previously with reference toFIG.10A.

Partial RU Allocation subfield contains B7-B0 out of B8-B0 of RU Allocation subfield specified in RU Allocation subfield in 802.11be D1.1 and can indicate all RU/MRU specified within PPDU BW of 20 MHz.

SU/MU-MIMO subfield indicates the recommended EHT-MCS with SU-MIMO or MU-MIMO applies to the PPDU. Set to 0 to indicate SU-MIMO; set to 1 to indicate MU-MIMO.

If the BW subfield is set to 1, 2, 3, 4 or 5 (indicating the PPDU bandwidth of recommended EHT-MCS/RU/MRU to be 40, 80, 160, 320-1 or 320-2 MHz), this subfield contains RU Allocation only as described above with reference toFIG.10Bspecified in RU Allocation subfield in 802.11be D1.1.

If the Unsolicited MFB is 1 and the UL EHT TB PPDU MFB is 0, this (Partial) RU Allocation subfield indicates the RU/MRU for which the recommended EHT-MCS applies to the PPDU sent to the STA.

If the Unsolicited MFB is 1 and the UL EHT TB PPDU MFB is 1, this (Partial) RU Allocation indicates the RU/MRU for which the recommended EHT-MCS applies to the EHT TB PPDU sent from the STA and that the actual allocation of the RU/MRU can be ignored by the recipient.

If the Unsolicited MFB is 0 and the MRQ is 1, this (Partial) RU Allocation subfield indicates the RU/MRU requested by the MFB requester to get feedback.

The RU Allocation is interpreted with the PPDU BW to specify the RU/MRU.

Otherwise, this subfield is reserved.

BW (PPDU Bandwidth of the recommended EHT-MCS/PPDU Bandwidth specified by MFB requester to get feedback)

If the Unsolicited MFB is 1 and the UL EHT TB PPDU MFB is 0, the BW indicates the bandwidth for which the recommended EHT-MCS applies to the PPDU sent to the STA.

If the Unsolicited MFB is 1 and the UL EHT TB PPDU MFB is 1, the BW indicates the bandwidth for which the recommended EHT-MCS applies to the EHT TB PPDU sent from the STA.

If the Unsolicited MFB is 0 and the MRQ is 1, the BW indicates the PPDU bandwidth requested by the MFB requester to get feedback.

Set to 0 for 20 MHz. Set to 1 for 40 MHz. Set to 2 for 80 MHz. Set to 3 for 160 MHz. Set to 4 for 320-1 MHz. Set to 5 for 320-2 MHz.

Otherwise, this subfield is reserved.

Tx Beamforming (Transmission type of the measured PPDU):

If the Unsolicited MFB subfield is 1 and the UL EHT TB PPDU MFB subfield is 0, then the Tx Beamforming subfield indicates whether or not the PPDU from which the unsolicited MFB was estimated is beamformed.

Set to 0 for non-beamformed PPDU

Set to 1 for beamformed PPDU

Otherwise, this subfield is reserved.

UL EHT TB PPDU MFB (UL EHT TB PPDU MFB indication):If the Unsolicited MFB subfield is 1, a value of 1 in this subfield indicates that the NSS, EHT-MCS, BW and RU Allocation fields represent the recommended MFB for the EHT TB PPDU sent from the STA.Otherwise, this subfield is reserved.

MSI/(PPDU Format, Coding Type)/(PPDU Format, SU/MU-MIMO) (MRQ sequence identifier/PPDU Format, Coding Type and SU/MU-MIMO type of the measured PPDU)

If the Unsolicited MFB subfield is 0 and the MRQ subfield is 1, as shown inFIG.11Athis subfield contains a sequence number in the range 0 to 3 that identifies the specific EHT-MCS feedback request.

If the Unsolicited MFB subfield is 0 and the MRQ subfield is 0, as shown inFIG.11Athis subfield contains a sequence number in the range 0 to 3 that responds to the specific solicited EHT-MCS feedback request.

If the Unsolicited MFB subfield is 1 and if the BW subfield is set to 0 (indicating the PPDU bandwidth of recommended EHT-MCS/RU/MRU to be 20 MHz), as shown inFIG.11Bthis subfield contains the PPDU Format (1 bit) (set 0 for indication of EHT MU PPDU; set 1 for EHT TB PPDU) and Coding Type (1 bit) (set 0 for indication of BCC; set 1 for LDPC) subfields.

If the Unsolicited MFB subfield is 1 and if the BW subfield is set to 1, 2, 3, 4 or 5 (indicating the PPDU bandwidth of recommended EHT-MCS/RU/MRU to be 40, 80, 160, 320-1 or 320-2 MHz), as shown inFIG.11Cthis subfield contains the PPDU Format (1 bit) (set 0 for indication of EHT MU PPDU; set 1 for EHT TB PPDU) and SU/MU-MIMO Type (1 bit) (set 0 for indication of SU-MIMO; set 1 for MU-MIMO) subfields

An advantage of the third embodiment includes maintaining the A-Control format unchanged and using only one reserved Control ID for indication of EHT LA control.

It can be seen that in the embodiment described above, the location of the SU/MU-MIMO indicator varies dependent upon the recommended BW, unsolicited MFB. This is to be understood as a specific example. More generally, there is some indicator within the 26 bits of control information of whether the EHT LA parameters apply to SU-MIMO or MU-MIMO. In some embodiments, there may be an exception to the need to include the SU/MU-MIMO indicator in certain cases, for example where the unsolicited MFB subfield is 0 as described above.

EHT Link Adaptation (EHT LA) Using One Control ID Value in A-Control Subfield of the HE Variant HT Control Field—Second Method

In accordance with a fourth embodiment, the Control ID value equal to 2 (for HLA in 802.11ax) is used to indicate LA parameters for both HE and HLA. The receiver determines which case is relevant on another basis, for example based on PHY layer parameters such as described for the second embodiment above. Table 4 below shows control ID assignments for this embodiment.

TABLE 4Control ID and EHT LA in A-Controlfield in the Fourth EmbodimentLength ofthe ControlContent of theControlInformationControlIDsubfieldInformationValueMeaning(bits)subfield...2HE link adaptation26when(HLA)/EHT LinkTXVECTORAdaptation (EHT LA)parameterFORMATindicates an HEPPDU, use HLAwhenTXVECTORparameterFORMATindicates an EHTPPDU, use EHTLA for SU MIMOor MU MIMOconfigurationsee below)...

In a specific example, the format of Control Information subfield in EHT Link Adaptation (EHT LA) is the same as that describe for the third embodiment previously with reference toFIGS.9,10and11. Furthermore, example definitions of EHT LA parameters in Control Information subfield are as described for the third embodiment above.

An advantage of the fourth embodiment includes maintaining the A-Control format unchanged and reuse Control ID value of 2 for indication of EHT LA control.

It can be seen that the third and fourth embodiments share the feature that a single ID is used for EHT LA. This is either a reserved control ID (third embodiment), or control ID 2 (fourth embodiment).

A flowchart of a method that encompasses the third and fourth embodiment is depicted inFIG.12. The method begins in block1200with communicating, by a wireless communication device, a medium access control (MAC) frame comprising a MAC header, frame body and frame check sequence. The MAC header has a high throughput (HT) control sub-field, the HT control sub-field containing a control ID value and control information, as indicated at1202. When the control ID value is set to a first value, the control information contains EHT link adaptation parameters for EHT communication, and the control information contains an SU/MU-MIMO indication of whether the control information is for SU-MIMO or for MU-MIMO, as indicated at1204. The first value is 2 in some embodiments, and in others, it is a one of 9, 11, 12, 13, 14. Many examples are described above for the indication of whether the control information is for SU-MIMO or for MU-MIMO, any of which can be applied here.

InFIG.12, The communicating can involve receiving by an access point. Alternatively communicating can involve transmitting by an access point. The communicating can involve receiving by a non-AP station. Alternatively communicating can involve transmitting by a non-AP station.

In some embodiments, a transmitter, which may be an AP or a non-AP STA for example, determines EHT LA link adaptation information for EHT transmission for SU-MIMO or MU-MIMO. Detailed examples of EHT LA parameters are described above. Determining the EHT LA parameters can involve making channel measurements. The transmitter then sends the EHT LA information using one of the methods described above. After that, data transmission takes place using the updated EHT LA parameters. This is done until the EHT LA parameters are updated again.

Numerous modifications and variations of the present disclosure are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the disclosure may be practiced otherwise than as specifically described herein.