Communication system, apparatus, method, and non-transitory computer-readable storage device for allocating multiple-input multiple-output communication using stream-based modulation coding system

Abstract

A first multiple output (MIMO) communication method has the steps of: generating signaling for one or more devices; and transmitting the signaling to the one or more devices; for each device of the one or more devices, the signaling is configured to indicate a plurality of streams allocated to the device and a plurality of modulation and coding system (MCS) indices, each MCS index corresponding to one of the streams. Accordingly, a second MIMO communication method has the steps of: receiving signaling from a device to obtain a plurality of streams and a plurality of MCS indexes corresponding to the streams; and transmitting a signal using the stream, in which a parameter for each stream is defined by a corresponding MCS index. In some embodiments, the signaling is carried in a trigger frame for uplink MIMO communication or in a physical layer protocol data unit for downlink MIMO communication.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 533,188, filed August 17, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to communication systems, apparatus, methods, and non-transitory computer-readable storage devices, and more particularly to communication systems, apparatus, methods, and non-transitory computer-readable storage devices that employ stream-based modulation and coding systems to allocate multiple-input multiple-output (MIMO) communication (e.g., uplink multi-user MIMO communication). Background Technology

[0004] In 802.11ac ( 5; WI-FI is a registered trademark of the Wi-Fi Alliance in Austin, Texas, USA) and 802.11ax ( 6) In wireless communication systems such as the system, multiple-input multiple-output (MIMO) technology can be used. This technology utilizes multiple antennas in the access point (AP) and / or station (STA) to form multiple spatial streams (or simply "streams") between the AP and STA for communication between them.

[0005] In such systems, the modulation and coding system (MCS; also known as a "modulation and coding scheme") defines multiple candidate MCS indices (the set of these candidate MCS indices is represented as an MCS table). Each MCS index represents a set of modulation and coding parameters, such as modulation type, coding rate, number of streams, channel width, and orthogonal frequency-division multiplexing (OFDM) guard interval. Therefore, different MCS indices represent different communication performance. APs and STAs can negotiate the MCS indices used to establish communication between them.

[0006] For uplink (UL) communication from STAs to an AP, UL multi-user multiple-input multiple-output (MU-MIMO) technology can be used to enable multiple STAs to transmit signals to the AP simultaneously using multiple streams. In the prior art, a STA can be allocated one MCS index regardless of how many streams are assigned to the STA. Therefore, if a STA is allocated a low-performance MCS index, the communication performance of the STA can be severely degraded. SUMMARY

[0007] According to one aspect of the disclosure, a first multiple-input multiple-output (MIMO) communication method is provided, the MIMO communication method comprising: generating signaling for one or more devices; and transmitting the signaling to the one or more devices; for each device of the one or more devices, the signaling is used to indicate a number of streams allocated to the device and a number of modulation and coding system (MCS) indexes, each MCS index corresponding to one stream of the number of streams.

[0008] In some embodiments of the first MIMO communication method, the one or more devices are one or more stations (STAs).

[0009] In some embodiments of the first MIMO communication method, the signaling comprises a first indication and a second indication for each device of the one or more devices; and for each device of the one or more devices, the first indication is used to indicate the number of streams allocated to the device, and the second indication is used to indicate the number of MCS indexes, each MCS index corresponding to one stream of the number of streams.

[0010] In some embodiments of the first MIMO communication method, the signaling is carried in a trigger frame for UL MIMO communication; the trigger frame comprises a user info field for each device; and the first indication and the second indication for each device are stored in the corresponding user info field of the trigger frame.

[0011] In some embodiments of the first MIMO communication method, the signaling is carried in a trigger frame for uplink (UL) multi-user MIMO (MU-MIMO) communication or for UL single-user MIMO (SU-MIMO) communication.

[0012] In some embodiments of the first MIMO communication method, the first indication further indicates a MCS table comprising a plurality of MCS sets, each of the plurality of MCS sets comprising a plurality of entries representing a plurality of candidate MCS indices for the plurality of streams, and the second indication comprises a MCS set index for indicating one of the plurality of MCS sets.

[0013] In some embodiments of the first MIMO communication method, the MCS table is one of a plurality of candidate MCS tables; the plurality of candidate MCS tables comprises a single-stream MCS table; and each of the MCS sets of the single-stream MCS table comprises a respective MCS index other than a MCS index for Dup mode.

[0014] In some embodiments of the first MIMO communication method, the plurality of candidate MCS indices of each of the MCS sets is arranged in a non-increasing or decreasing order as an index of the plurality of streams increases.

[0015] In some embodiments of the first MIMO communication method, the plurality of entries of each of the MCS sets is the plurality of candidate MCS indices of the MCS set; the plurality of entries of each of the MCS sets comprises a base candidate MCS index and one or more index difference values relative to the base candidate MCS index; or the plurality of entries of each of the MCS sets comprises a base candidate MCS index and one or more index difference values relative to an adjacent candidate MCS index of the base candidate MCS index.

[0016] In some embodiments of the first MIMO communication method, the second indication comprises the plurality of candidate MCS indices.

[0017] In some embodiments of the first MIMO communication method, the first indication and the second indication for each device are stored in the user info field of the trigger frame together with a unique identifier (ID).

[0018] In some embodiments of the first MIMO communication method, the first indication is stored in a spatial stream (SS) allocation / RA-RU information subfield of the user info field, and the second indication is stored in one or more of a UL MCS subfield, a first reserved subfield, a second reserved subfield, and a trigger related user info subfield of the user info field.

[0019] In some embodiments of the first MIMO communication method, the first indication is stored in the last two bits of the SS allocation / RA-RU information subfield of the user info field, and the second indication is stored in the UL MCS subfield of the user info field.

[0020] In some embodiments of the first MIMO communication method, the signaling is carried in a physical layer protocol data unit (PPDU) for downlink (DL) MIMO communication; and the first indication and the second indication for each device are stored in one or more signal (SIG) fields of the PPDU.

[0021] In some embodiments of the first MIMO communication method, the one or more SIG fields of the PPDU include one or more of an L-SIG field, an RL-SIG field, a U-SIG field, and an EHT-SIG field.

[0022] In some embodiments of the first MIMO communication method, the one or more SIG fields of the PPDU include an EHT-SIG field; and for DL MU-MIMO, the first indication and the second indication for each device are stored in one or more user specific fields of the EHT-SIG field, or for DL SU-MIMO, the first indication and the second indication for each device are stored in one or more common fields of the EHT-SIG field.

[0023] According to an aspect of the present disclosure, there is provided one or more circuits (e.g., at least one processing unit or at least one processor) for performing the above first MIMO communication method.

[0024] According to an aspect of the present disclosure, there is provided one or more non-transitory computer-readable storage devices including computer-executable instructions, wherein the instructions, when executed, cause one or more circuits (e.g., at least one processing unit or at least one processor) to perform the first MIMO communication method.

[0025] According to an aspect of the present disclosure, there is provided a second MIMO communication method, comprising: receiving signaling from a device to obtain a plurality of streams and a plurality of MCS indexes corresponding to the plurality of streams; and transmitting a plurality of signals to the device using the plurality of streams, wherein a parameter of each stream is defined by the corresponding one of the plurality of MCS indexes.

[0026] In some embodiments of the second MIMO communication method, the MIMO communication method is performed by a STA.

[0027] In some embodiments, the device is an access point (AP).

[0028] In some embodiments of the second MIMO communication method, the signaling includes a first indication to indicate the plurality of streams and a second indication to indicate the plurality of MCS indexes.

[0029] In some embodiments of the second MIMO communication method, the signaling is carried in a trigger frame for UL MIMO communication; and the first indication and the second indication are stored in a user information field of the trigger frame.

[0030] In some embodiments of the second MIMO communication method, the signaling is carried in a trigger frame for UL MU-MIMO communication or for UL SU-MIMO communication.

[0031] In some embodiments of the second MIMO communication method, the first indication further indicates a MCS table including a plurality of MCS sets, each MCS set including a plurality of entries representing a plurality of candidate MCS indexes of the plurality of streams, and the second indication includes a MCS set index to indicate one of the plurality of MCS sets.

[0032] In some embodiments of the second MIMO communication method, the MCS table is one of a plurality of candidate MCS tables; the plurality of candidate MCS tables includes a single-stream MCS table; and each MCS set of the single-stream MCS table includes a respective MCS index other than a MCS index of a Dup mode.

[0033] In some embodiments of the second MIMO communication method, the plurality of candidate MCS indices of each MCS set is arranged in a non-increasing or decreasing order as the index of the plurality of streams increases.

[0034] In some embodiments of the second MIMO communication method, the plurality of entries of each MCS set is the plurality of candidate MCS indices of the MCS set; the plurality of entries of each MCS set includes a base candidate MCS index and one or more index difference values relative to the base candidate MCS index; or the plurality of entries of each MCS set includes a base candidate MCS index and one or more index difference values relative to an adjacent candidate MCS index of the base candidate MCS index.

[0035] In some embodiments of the second MIMO communication method, the second indication includes the plurality of candidate MCS indices.

[0036] In some embodiments of the second MIMO communication method, the first indication and the second indication for each device are stored in the user info field of the trigger frame together with a unique ID.

[0037] In some embodiments of the second MIMO communication method, the first indication is stored in a SS allocation / RA-RU info subfield of the user info field, and the second indication is stored in one or more of a UL MCS subfield, a first reserved subfield, a second reserved subfield, and a trigger related user info subfield of the user info field.

[0038] In some embodiments of the second MIMO communication method, the first indication is stored in the last two bits of the SS allocation / RA-RU info subfield of the user info field, and the second indication is stored in the UL MCS subfield of the user info field.

[0039] In some embodiments of the second MIMO communication method, the signaling is carried in a PPDU for DL MIMO communication; and the first indication and the second indication are stored in one or more SIG fields of the PPDU.

[0040] In some embodiments of the second MIMO communication method, the one or more SIG fields of the PPDU include one or more of an L-SIG field, an RL-SIG field, a U-SIG field, and an EHT-SIG field.

[0041] In some embodiments of the second MIMO communication method, the one or more SIG fields of the PPDU comprise an EHT-SIG field; and for DL MU-MIMO, the first indication and the second indication for each device are stored in one or more user-specific fields of the EHT-SIG field, or for DL SU-MIMO, the first indication and the second indication for each device are stored in one or more common fields of the EHT-SIG field.

[0042] In some embodiments of the second MIMO communication method, the signal transmitted via each stream is independently encoded and / or interleaved from the signals transmitted via other streams.

[0043] According to an aspect of the present disclosure, there is provided one or more circuits (e.g., at least one processing unit or at least one processor) for performing the above-described second MIMO communication method.

[0044] According to an aspect of the present disclosure, there is provided one or more non-transitory computer-readable storage devices comprising computer-executable instructions, wherein the instructions, when executed, cause one or more circuits (e.g., at least one processing unit or at least one processor) to perform the above-described second MIMO communication method.

[0045] In the conventional method, the STA can have to adapt the worst stream in the allocated streams, and waste the capacity of other better streams. In comparison with the conventional method, the above-described first and second MIMO communication methods enable the AP and the STA to communicate with each other via multiple streams, wherein the communication parameters (represented by MCS indexes) are adapted to the characteristics of the streams, so as to better use the streams. Therefore, the communication performance achieved by the stream-based MCS allocation and indication methods disclosed herein is improved. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 is a simplified schematic diagram illustrating a communication system according to some embodiments of the present disclosure;

[0047] Figure 2 is Figure 1 a simplified schematic diagram of an access point (AP) of a communication network of the communication system shown;

[0048] Figure 3 is Figure 1 a simplified schematic diagram of a station (STA) of the communication system shown;

[0049] Figure 4 is a simplified schematic diagram illustrating Figure 1A schematic diagram of uplink (UL) multi-user multiple-input multiple-output (MU-MIMO) of the communication system shown;

[0050] Figure 5 is a graph showing the packet error rate (PER) performance of UL MU-MIMO of three scheduled STAs using prior art MCS allocation methods;

[0051] Figure 6 is a graph showing the PER performance of UL MU-MIMO of three scheduled STAs according to some embodiments of the present disclosure; Figure 1 is a schematic diagram of the structure of a trigger frame sent by an AP of the communication system shown to multiple STAs;

[0052] Figure 7 is a graph showing the PER performance of UL MU-MIMO of three scheduled STAs according to some embodiments of the present disclosure; Figure 6 is a schematic diagram of the structure of the user info field of the trigger frame shown;

[0053] Figure 8 is a graph showing the PER performance of UL MU-MIMO of three scheduled STAs according to some embodiments of the present disclosure; Figure 1 is a flowchart of a notification procedure performed by an AP of the communication system shown for notifying multiple STAs of their allocated streams and corresponding MCS indices;

[0054] Figure 9 is a flowchart of a procedure performed by a STA of the communication system shown for establishing UL communication with the AP using allocated streams; Figure 1

[0055] is a graph showing the PER comparison between two methods of UL MU-MIMO of three (3) STAs to an AP of the communication system shown, the two methods being Figure 10 and Figure 1 is a graph showing the effective throughput comparison between two methods of UL MU-MIMO of three (3) STAs to an AP of the communication system shown, the two methods being Figure 8 and Figure 9 is a graph showing the PER comparison between two methods of UL MU-MIMO of three (3) STAs to an AP of the communication system shown, the two methods being

[0056] Figure 11 is a graph showing the effective throughput comparison between two methods of UL MU-MIMO of three (3) STAs to an AP of the communication system shown, the two methods being Figure 1 Figure 8 Figure 9 is a graph showing the PER comparison between two methods of UL MU-MIMO of three (3) STAs to an AP of the communication system shown, the two methods being

[0057] Figure 12 ​​This illustrates some embodiments of the present disclosure from Figure 1 The diagram shows the structure of an AP in a communication system that transmits extremely high throughput (EHT) physical layer protocol data units (PPDUs) to multiple STAs. Detailed Implementation

[0058] The embodiments disclosed herein relate to wireless systems, apparatuses, and methods; communication systems, apparatuses, methods, and non-transitory computer-readable storage devices employing stream-based modulation and coding systems for allocating uplink multiple-input multiple-output (MU-MIMO) communications. The wireless systems, apparatuses, and methods disclosed herein can be any suitable system, apparatus, and method for transmitting wireless signals. Examples of such systems may include… Systems, 5G or 6G wireless mobile communication systems, etc.

[0059] A. System Structure

[0060] See below. Figure 1 The illustration shows a communication system according to some embodiments of the present disclosure, which is generally identified by reference numeral 100. For example, the communication system 100 may be constructed in accordance with relevant standards such as the IEEE 802.11 standard. The system, as shown in the figure, includes multiple interconnected networking devices 102, such as multiple interconnected access points (APs; also called "base stations") forming a distribution system (DS) 104. The distribution system 104 is connected to other networks such as the Internet 108. The Internet 108 may include computer networks and subnets (intranets) or both, and may incorporate protocols such as Internet Protocol (IP), Transmission Control Protocol (TCP), and / or User Datagram Protocol (UDP).

[0061] Each AP 102 communicates wirelessly with one or more mobile or stationary stations (STAs) 112 over respective wireless channels 114 to provide wireless network connectivity for them. In this document, APs 102 and STAs 112 can be regarded as different types of network nodes (or simply “nodes”) of communication system 100. Each AP 102 and the STAs 112 connected to it form a cell or a basic service set (BSS) 118.

[0062] Figure 2 is a simplified schematic diagram of an AP 102. As shown, the AP 102 includes at least one processing unit 142 (also denoted as at least one “processor”), at least one transmitter (TX) 144, at least one receiver (RX) 146 (collectively referred to as a transceiver), one or more antennas 148, at least one memory 150, and one or more input / output components or interfaces 152. A scheduler 154 can be coupled to the processing unit 142. The scheduler 154 can be included within the AP 102 or can operate separately from the AP 102. Each of these components 142-154 can be implemented as one or more circuits (e.g., one or more electronic circuits and / or one or more optical circuits). Alternatively, the entirety of these components 142-154 can be implemented as one or more circuits.

[0063] The processing unit 142 is configured to perform various processing operations, such as signal coding, data processing, power control, input / output processing, or any other appropriate function. The processing unit 142 can include a microprocessor, a microcontroller, a digital signal processor, a FPGA, and / or an ASIC, among others. In some embodiments, the processing unit 142 can execute computer-readable instructions or code stored in the memory 150 to perform various processes described below (or methods, as the case can be).

[0064] Each transmitter 144 can include any suitable structure for generating signals (e.g., control signals described in detail below) for wireless transmission to one or more STAs 112. Each receiver 146 can include any suitable structure for processing signals wirelessly received from one or more STAs 112. Although illustrated as separate components, the at least one transmitter 144 and the at least one receiver 146 can be integrated and implemented as a transceiver. Each antenna 148 can include any suitable structure for transmitting and / or receiving wireless signals. Although shown as separate components, the at least one transmitter 144 and the at least one receiver 146 can be integrated and implemented as a transceiver. Figure 2The common antenna 148 is shown coupled to both the transmitter 144 and the receiver 146, although one or more antennas 148 can be coupled to the transmitter 144 and one or more other antennas 148 can be coupled to the receiver 146.

[0065] In some embodiments, the AP 102 can include multiple transmitters 144 and receivers 146 (or transceivers) and multiple antennas 148 for communicating in its cell 118.

[0066] Each memory 150 can include any suitable volatile and / or non-volatile storage such as RAM, ROM, hard disks, optical disks, SIM cards, solid-state memory, memory sticks, and / or SD memory cards, etc. The memory 150 can be used to store instructions executable by the processing unit 142, as well as data used, generated, or collected by the processing unit 142. For example, the memory 150 can store instructions of software, software systems, or software modules executable by the processing unit 142 for implementing embodiments of some or all of the functions and / or processes performed by the AP 102 described herein.

[0067] Each input / output component 152 can enable interaction with a user or other devices in the communication system 100. Each input / output device 152 can include any suitable structure for providing information to or receiving information from a user, and can be, for example, a speaker, a microphone, a keypad, a keyboard, a display, a touchscreen, and / or a network communication interface, etc.

[0068] In this document, a STA 112 can be any suitable wireless electronic device that can join the communication system 100 through the AP 102 for wireless operation. In various embodiments, the STA 112 can be a wireless electronic device used by a person or user (e.g., a smartphone, a cellular telephone, a personal digital assistant (PDA), a notebook computer, a desktop computer, a tablet computer, a smartwatch, and / or a consumer electronic device, etc.). Alternatively, the STA 112 can be a wireless sensor, an Internet-of-things (IoT) device, a robot, a shopping cart, a vehicle, a smart TV, a smart appliance, a wireless transmit / receive unit (WTRU), or a mobile station, etc. Depending on the implementation, the STA 112 can move autonomously or under the direct or remote control of a person, or can be positioned at a fixed location.

[0069] In some embodiments, the STA 112 can be a multi-mode wireless electronic device capable of operating according to multiple wireless access technologies, and incorporate multiple transceivers needed to support such operation.

[0070] In addition, some or all of the STAs 112 have the functionality to communicate with different wireless devices and / or wireless networks using different wireless technologies and / or protocols via different wireless links. In addition to (or instead of) wireless communication, the STAs 112 can communicate with other devices or switches (not shown) through wired communication channels, as well as with the Internet 106. For example, multiple STAs 112 (e.g., STAs 112 that are proximate to each other) can communicate directly with each other through suitable wired or wireless sidelinks.

[0071] Figure 3 is a simplified schematic diagram of a STA 112. As shown, the STA 112 includes at least one processing unit 202, at least one transceiver 204, at least one antenna or network interface controller (NIC) 206, at least one positioning module 208, one or more input / output components 210, at least one memory 212, and at least one other communication component 214. Each of these components 202-214 can be implemented as one or more circuits (e.g., one or more electrical circuits and / or one or more optical circuits). Alternatively, the entirety of these components 202-214 can be implemented as one or more circuits.

[0072] The processing unit 202 is configured to perform various processing operations, such as signal coding, data processing, power control, input / output processing, or any other functionality enabling the STA 112 to access and operate within the communication system 100. The processing unit 202 can also be configured to implement some or all of the functionality of the STA 112 described in this disclosure. The processing unit 202 can include a central processing unit (CPU), a microprocessor, a microcontroller, a digital signal processor, an accelerator, a graphic processing unit (GPU), a tensor processing unit (TPU), an FPGA, or an ASIC. An example of the processing unit 202 can be a Snapdragon processor by Qualcomm Inc. of San Diego, CA, USA, or the like, manufactured under an ARM® architecture by various manufacturers based on designs of Arm Ltd. of Cambridge, UK, an Intel® Core® microprocessor (INTEL is a registered trademark of Intel Corp. of Santa Clara, CA, USA), and the like. The processing unit 202 is configured to perform various processing operations, such as signal coding, data processing, power control, input / output processing, or any other functionality enabling the STA 112 to access and operate within the communication system 100. The processing unit 202 can also be configured to implement some or all of the functionality of the STA 112 described in this disclosure. The processing unit 202 can include a central processing unit (CPU), a microprocessor, a microcontroller, a digital signal processor, an accelerator, a graphic processing unit (GPU), a tensor processing unit (TPU), an FPGA, or an ASIC. An example of the processing unit 202 can be a Snapdragon processor by Qualcomm Inc. of San Diego, CA, USA, or the like, manufactured under an ARM® architecture by various manufacturers based on designs of Arm Ltd. of Cambridge, UK, an Intel® Core® microprocessor (INTEL is a registered trademark of Intel Corp. of Santa Clara, CA, USA), and the like. ​​microprocessors (AMD is a registered trademark of Advanced Micro Devices, Inc., Sunnyvale, California, USA), etc. In some embodiments, the processing unit 202 can execute computer-executable instructions or code stored in the memory 212 to perform various processes described below.

[0073] The at least one transceiver 204 can be used to modulate data or other content transmitted by the at least one antenna 206 for communication with the AP 102. The transceiver 204 is also used to demodulate data or other content received by the at least one antenna 206. Each transceiver 204 can include any suitable structure for generating signals for wireless transmission and / or for processing signals received wirelessly. Each antenna 206 can include any suitable structure for transmitting and / or receiving wireless signals. Although the transceiver 204 is shown as a single functional unit, it can also be implemented separately as at least one transmitter and at least one receiver.

[0074] The positioning module 208 is used to communicate with a plurality of global or regional positioning devices (e.g., navigation satellites) to determine the location of the STA 112. The navigation satellites can be satellites of a global navigation satellite system (GNSS), such as the Global Positioning System (GPS) of the United States, the Global'naya Navigatsionnaya Sputnikovaya Sistema (GLONASS) of Russia, the Galileo positioning system of the European Union, and / or the BeiDou system of China. The navigation satellites can also be satellites of a regional navigation satellite system (RNSS), such as the Indian Regional Navigation Satellite System (IRNSS) of India or the Quasi-Zenith Satellite System (QZSS) of Japan, etc. In other embodiments, the positioning module 208 can be used to communicate with a plurality of indoor positioning devices to determine the location of the STA 112.

[0075] The one or more input / output components 210 are used to interact with a user or other devices in the communication system 100. Each input / output component 210 can include any suitable structure for providing information to or receiving information from a user, and can be, for example, a speaker, a microphone, a keypad, a keyboard, a display, and / or a touchscreen, etc.

[0076] The at least one memory 212 is used to store instructions executable by the processing unit 202, as well as data used, generated, or collected by the processing unit 202. For example, the memory 212 can store instructions executable by the processing unit 202 for implementing some or all of the functionality of the STA 112 described herein and / or embodiments. Each memory 212 can include any suitable volatile and / or non-volatile storage and retrieval components, such as RAM, ROM, hard drives, optical drives, SIM cards, solid-state memory modules, memory sticks, and / or SD memory cards, etc.

[0077] The at least one other communication component 214 is used to communicate with other devices, such as other STAs 112, through wireless links, Other communication means, such as wired sidelinks (BLUETOOTH is a registered trademark of Bluetooth SIG, Inc. of Kirkland, Washington, USA) and / or wired sidelinks, etc. An example of a wired sidelink can be a USB cable, a network cable, a parallel cable, and / or a serial cable, etc.

[0078] In some embodiments, the STA 112 can include multiple transceivers 204 and multiple antennas 206 for communicating with the AP 102.

[0079] In communications between the AP 102 and the STA 112, transmissions from the STA 112 to the AP 102 are generally denoted as uplink (UL), and the wireless channel used for the transmissions is denoted as the uplink channel. Transmissions from the AP 102 to the STA 112 are generally denoted as downlink (DL), and the wireless channel used for the transmissions is denoted as the downlink channel. Appropriate modulation techniques can be used for communications between the AP 102 and the STA 112. For example, in some embodiments, orthogonal frequency-division multiplexing (OFDM) can be used, in which the channel 114 is divided into multiple orthogonal sub-channels for communications between the AP 102 and the STA 112. Furthermore, since there are typically multiple STAs 112 communicating with the same AP 102, appropriate multiple access techniques can be used. For example, in some embodiments, orthogonal frequency-division multiple access (OFDMA) can be used for communications between the AP 102 and the STA 112.

[0080] B. MCS allocation and indication

[0081] By using multiple antennas at the AP side and / or at the STA side, the AP 102 and the STAs 112 can use multiple-input multiple-output (MIMO) technology for communication between them, where such a system 100 can be denoted as a “MIMO system”. More specifically, MIMO technology can be used for communication between the AP 102 and a single STA 112 (denoted as “SU-MIMO”) or between the AP 102 and multiple STAs 112 (denoted as “MU-MIMO”). Furthermore, SU-MIMO can also be divided into DL SU-MIMO (for DL communication, i.e. the AP 102 transmits signals to a single STA 112) and UL SU-MIMO (for UL communication, i.e. a single STA 112 transmits signals to the AP 102). Similarly, MU-MIMO can also be divided into DL MU-MIMO (for DL communication, i.e. the AP 102 transmits signals to multiple STAs 112) and UL MU-MIMO (for UL communication, i.e. multiple STAs 112 transmit signals to the AP 102 simultaneously). For example, in the 802.11ax standard (also denoted as “Wi-Fi 6”) 6), UL MU-MIMO can be used.

[0082] Figure 4 is a schematic diagram showing an example of a communication system 100 using UL MU-MIMO. For ease of illustration, Figure 4 only one AP 102 (also denoted as “AP-1”) and N STAs 112 (also denoted as “STA-1”, “STA-2”,... “STA-N”) are shown. The AP 102 comprises TX antennas 148 (denoted as “TX antennas TX-1 to ”, although they can also receive signals in UL communication), and the nth STA (STA-n) comprises RX antennas 206 (denoted as “RX antennas RX-1 to ”, although they can also transmit signals in UL communication).

[0083] In this example, the AP 102 can typically have up to 8 TX antennas 148, but each STA 112 is limited by the number of RX antennas 206. Multiple STAs 112 can simultaneously transmit their UL data packets via different spatial streams (or simply “streams”) over the wireless channel, which is referred to as UL MU-MIMO.

[0084] Since the STA-n has RX antennas 206, the maximum number of streams for UL data packet transmission from the STA-n to the AP 102 is less than or equal to Since the number of TX antennas 148 at the AP-1 is , the total number of streams (i.e., the sum from to ) is less than or equal to .

[0085] The eigenvalues of the UL streams (represented by the singular values of the diagonal matrix after singular value decomposition (SVD) of the channel matrix) are arranged in descending order from the first stream (corresponding to the top singular value of the diagonal matrix) to the last stream (corresponding to the bottom singular value of the diagonal matrix) (similar to the DL MIMO channel). The first streams in the total number of streams in the UL MU-MIMO transmission are allocated to the SAT-1, the next streams in the UL MU-MIMO transmission starting from the stream are allocated to the STA-2, and the last streams in the total number of streams in the UL MU-MIMO transmission are allocated to the STA-N. Therefore, the eigenvalues of these streams detected at the AP side after MIMO detection are arranged in descending order from the first stream to the stream.

[0086] In the prior art, the same MCS can be allocated in the UL MU-MIMO at each scheduled STA regardless of the number of allocated streams of each scheduled STA. Therefore, the worst MCS on the allocated streams in each scheduled STA will be assigned to all the allocated streams of the scheduled STA. This can degrade the average packet error rate (PER) performance of each scheduled STA.

[0087] Figure 5 is a graph showing the PER performance of UL iterative beamforming and UL MU-MIMO without UL beamforming of three scheduled STAs 112 (STA-1, , and ) when using the prior art MCS allocation method, where each STA 112 is allocated with two streams. In the legend of Figure 5 , "ITULBF" refers to UL iterative beamforming, "UL w / o BF" refers to UL MU-MIMO without UL beamforming, and "p x q" refers to p TX antennas and q RX antennas (e.g., 6 x 8 refers to 6 TX antennas and 8 RX antennas).

[0088] As shown, for each MCS (A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z), the performance is best for , or , , followed by and . When averaged over two streams in each STA, the three STAs still exhibit SNR differences at the same PER, where is assigned to the first two streams, is assigned to the next two streams, is assigned to the last two streams. Regarding the SNR range at the same PER, is best, followed by and .

[0089] In some embodiments, the communication system 100 can use a stream-based MCS allocation method to allocate an MCS index for each UL stream of each scheduled STA 112 in the UL. Thus, a STA 112 allocated with multiple UL streams can be allocated with multiple MCS indexes, where the allocated MCS indexes can have different index values, or some of the allocated MCS indexes can have the same index value. Such a stream-based MCS allocation method can greatly reduce the likelihood of the communication performance of a STA deteriorating due to “suboptimal” MCS allocation.

[0090] Various embodiments are described below, in which different MCS indexes allocated to different streams of each scheduled STA 112 can be indicated using a suitable signaling method. In this context, the term “signaling” refers to the use of a particular signal to control communication, while the term “signal” generally refers to information transmitted between devices (e.g., between the AP 102 and one or more STAs 112).

[0091] More specifically, signaling can be sent from a first device (e.g., the AP 102) to one or more second devices (e.g., one or more STAs 112) for indicating different MCS indexes allocated to different streams of a scheduled STA 112. Each STA 112 receives the signaling sent from the AP 102 to obtain multiple allocated streams and multiple MCS indexes corresponding to the multiple allocated streams, and then transmits multiple signals to the device using the multiple allocated streams, where the parameters of each allocated stream are defined by the corresponding MCS index.

[0092] In some embodiments, the signaling can be carried in a trigger frame for UL MIMO communication (e.g., UL MU-MIMO and / or UL SU-MIMO). In some embodiments, the signaling can be carried in a physical layer protocol data unit (PPDU) for DL MIMO communication (e.g., DL MU-MIMO and / or DL SU-MIMO).

[0093] The MCS allocation and indication methods disclosed herein can be used in various systems, such as 8, while providing backward compatibility to 6 (IEEE 802.11ax, also denoted as “high efficiency (HE)”) and 7 (IEEE 802.11be, also denoted as “extremely high throughput (EHT)”) and other “legacy” standards.

[0094] Those skilled in the art can understand that, in In a system, an AP 102 can send a trigger frame to a STA 112 for informing the STA 112 of information (e.g., scheduling information) or requesting information from the STA 112. In 6 and 7 and other prior arts, a MCS index allocated to a scheduled STA 112 in UL MU-MIMO is indicated in the trigger frame.

[0095] In some embodiments, the trigger frame can be used to indicate a flow-based MCS allocation.

[0096] Figure 6 The structure of a variant trigger frame 300 in these embodiments is shown. As shown, the trigger frame 300 includes:

[0097] • a frame control field 302 of two (2) octets (i.e., 16 bits, where one octet is equal to eight (8) bits),

[0098] • a duration field 304 of two (2) octets,

[0099] • a receiving STA address (RA) field 306 of six (6) octets (indicating the address of a STA (denoted as “receiving STA”) to which the trigger frame 300 is sent, e.g., the broadcast address of the receiving STA),

[0100] • a six (6) octet transmitting AP address (TA) field 308,

[0101] • an eight (8) or more octet public information field 310,

[0102] • a variable length user info list field 312,

[0103] • a variable length padding field 314, and

[0104] • a four (4) octet frame check sequence (FCS) field 316.

[0105] The entirety of the frame control field 302, the duration field 304, the RA field 306, and the TA field 308 can be denoted as a media access control (MAC) header.

[0106] The user info list field 312 includes one or more user info fields (denoted as 312') for one or more receiving STAs 112, where each user info field 312' includes detailed information for a corresponding receiving STA 112.

[0107] Figure 7 Detailed information of the user info field 312' is shown. As shown, the user info field 312' includes:

[0108] • a 12-bit association identifier (AID) subfield 342 (from bit 0 (B0) to bit 11 (B11)) for indicating an identifier of the receiving STA,

[0109] • an 8-bit RU allocation subfield 344 (from B12 to B19) for indicating a resource unit (RU) allocated to the receiving STA,

[0110] • a 1-bit UL forward error correction (FEC) encoding type subfield 346 (B20),

[0111] • a 4-bit UL ultra high reliability (UHR) MCS subfield 348 (from B21 to B24),

[0112] • a first 1-bit reserved subfield 350 (B25) (which can be used to indicate UL dual carrier modulation (DCM)),

[0113] • a 6-bit spatial stream (SS) allocation / RA-RU information subfield 352 (B26-B31),

[0114] • a 7-bit UL target received power subfield 354 (e.g., UL target received signal strength indicator (RSSI) subfield) (from B32 to B38),

[0115] • a second 1-bit reserved subfield 356 (B39), and

[0116] • a variable length trigger-related user info subfield 358.

[0117] In 6 and 7, the 4-bit UL MCS subfield (which corresponds to the UL UHR MCS subfield 348 in these embodiments) is used to indicate the MCS index assigned to the receiving STA. In HE, the 6-bit SS allocation / RA-RU information subfield 352 includes three (3) bits to indicate the number of streams allocated to the receiving STA (more specifically, equal to the number of allocated streams plus one) and three (3) bits to indicate the starting stream among the allocated streams. In EHT, the first four (4) bits of the SS allocation / RA-RU information subfield 352 are used to indicate the starting stream among the allocated streams, and the last two (2) bits are used to indicate the number of allocated streams.

[0118] In these embodiments, the 4-bit UL MCS subfield 348 and the 6-bit SS allocation / RA-RU information subfield 352 are used to indicate one or more streams allocated to the receiving STA and the corresponding one or more MCS indices.

[0119] More specifically, in these embodiments, L MCS tables (L > 1, is a predefined integer) can be predefined and known to both the AP 102 and the STAs 112 that will be scheduled for UL MU-MIMO transmission. The l-th MCS table (L ≥ l ≥ 1) defines a set of multiple MCS indices (also simply denoted as “MCS set”) for l streams to be allocated to each STA 112, where each MCS set includes a predefined l candidate MCS indices for the l streams, and these candidate MCS indices are arranged in non-increasing order from the first stream among the l streams to the last stream among the l streams. The L MCS tables can or can not have the same number of MCS sets.

[0120] When the AP 102 allocates streams to the STA 112, the AP 102 first determines the number of streams (e.g., i streams, where L > i > 1). Then, the AP 102 determines a MCS set index j from the i-th MCS table and transmits j and i to the STA 112 using the UL MCS subfield 348 and the SS assignment / RA-RU information subfield 352, respectively, where i indicates the number of streams allocated to the STA 112 and the corresponding MCS table, and j indicates the MCS index of the stream allocated to the STA 112, requiring bits to be stored in the trigger frame, j indicates the MCS index of the stream allocated to the STA 112, requiring bits to be stored in the trigger frame, where is the maximum number of rows (i.e., the maximum number of MCS sets in the L MCS tables) for the L MCS tables.

[0121] For example, in some embodiments, four (4) MCS tables can be predefined and known to both the AP 102 and the STA 112 (i.e., L = 4), including the following four MCS tables, where is 15 (i.e., the first MCS table has the maximum number of MCS sets among the four (4) MCS tables).

[0122] The first MCS table (Table 1) includes the base UHR MCS indices 0-13 and 15, excluding the Dup mode (EHT-MCS 14) for one allocated stream. The second, third, and fourth MCS tables (Tables 2-4) each include 10 MCS sets, each having two, three, and four MCS indices, respectively, arranged in non-increasing order from the first allocated stream to the last allocated stream, i.e., if p > q, the MCS index of the p-th allocated stream is greater than or equal to the MCS index of the q-th allocated stream. Furthermore, in each MCS table, the MCS set index can be any suitable index, e.g., starting from zero (0) but not necessarily increasing by one (1) (Table 1, where the MCS set index skips 14), or starting from one (1) and increasing by one (1) (Tables 2-4).

[0123] Table 1: First MCS table for one allocated stream

[0124]

[0125] Table 2: Second MCS table for two allocated streams

[0126]

[0127] Table 3: Third MCS table for three allocated streams

[0128]

[0129] Table 4: Fourth MCS table for four allocated streams

[0130]

[0131] In this example, four MCS tables are used (i.e., 4 > i > 1), so two bits are needed to indicate i. Among the four MCS tables, the maximum number of MCS index sets is 16 (i.e., 16 > j > 1), so four bits are needed to indicate j. Thus, in this example, the last two bits B30 and B31 of the SS Allocation / RA-RU Information subfield 352 can be used to store i (indicating the number of streams allocated to the STA 112 and the corresponding MCS table), and the 4-bit UL MCS subfield 348 can be used to store j (indicating the MCS index of the allocated stream).

[0132] In some embodiments, the encoding of each stream (e.g., each UL stream) is based on multiple code words. In other words, the signal transmitted via each stream is encoded and / or interleaved independently of the signals transmitted via the other streams. When different MCS indexes are allocated to each stream in a DL SU / MU-MIMO transmission, multiple code word based encoding and interleaving can also be necessary.

[0133] In some embodiments, the combination of the 4-bit UL MCS subfield 348 and the two 1-bit reserved subfields 350 and 356 (i.e., the six (6) bits of B21 to B25 and B39) can be used to indicate the MCS index assigned to the receiving STA 112, such that each MCS table has up to 64 combinations.

[0134] In some embodiments, more bits in the trigger frame 300 can be used to indicate the MCS index assigned to the receiving STA 112, such that each MCS table has more combinations. For example, in some embodiments, the bits of B21 to B25 and B39 (i.e., the UL MCS subfield 348 and the two reserved subfields 350 and 356) and one or more bits in the Trigger Related User Info subfield 358 can be used to indicate the MCS index assigned to the receiving STA 112.

[0135] In some embodiments, one or more of the UL MCS subfield 348, the reserved subfield 350, and the reserved subfield 356 can be used to indicate the MCS index assigned to the receiving STA 112.

[0136] In some embodiments, one or more of the UL MCS subfield 348, the reserved subfield 350, and the reserved subfield 356 can be combined with one or more bits in the trigger-related user info subfield 358 for indicating the MCS index assigned to the receiving STA 112.

[0137] In some embodiments, the UL MCS subfield 348 and the two reserved subfields 350 and 356 can not be used for indicating the MCS index assigned to the receiving STA 112. Instead, one or more bits in the trigger-related user info subfield 358 can be used for indicating the MCS index assigned to the receiving STA 112. In these embodiments, a new type of trigger frame 300 (e.g., denoted as “UHR basic trigger frame”) can be introduced and the necessary information (e.g., sub-subfields) can be defined in the trigger-related user info subfield 358.

[0138] In the above embodiments, in the MCS table for multiple streams (e.g., Tables 2-4 above), each MCS set includes the MCS index of multiple streams. In some embodiments, in the MCS table for multiple streams, each MCS set can include the MCS index of a predefined one of the multiple streams (e.g., the first stream) in bits (denoted as “base MCS index”) and the index difference D of each of the other streams with respect to the base MCS index in bits, wherein so that the MCS index of the stream can be obtained, i.e., ( ); see Tables 5-7. Note that the index difference D for different streams and / or different MCS sets can or can not be the same value.

[0139] Table 5: MCS table for two allocated streams using MCS index difference

[0140]

[0141] Table 6: MCS table for three allocated streams using MCS index difference

[0142]

[0143] Table 7: MCS table for four allocated streams using MCS index difference

[0144]

[0145] In some embodiments, in the MCS table for multiple streams, each MCS set can include the base MCS index of a predefined base stream of the multiple streams in bits (denoted as “base MCS index”) and an index difference D of bits for each of the other streams relative to the previous MCS index, wherein .

[0146] For example, as shown in Tables 8-10, in the MCS table for multiple streams, the first stream is predefined as the base stream. Each MCS set includes a base MCS index of bits for the first stream and an index difference D of bits for each of the other streams relative to the previous MCS index, wherein .

[0147] Table 8: MCS table for two allocated streams using adjacent MCS index difference

[0148]

[0149] Table 9: MCS table for three allocated streams using adjacent MCS index difference

[0150]

[0151] Table 10: MCS table for four allocated streams using adjacent MCS index difference

[0152]

[0153] In some embodiments, no MCS table is used. In these embodiments, the trigger frame 300 includes multiple MCS indexes, each for a corresponding allocated stream. For example, the trigger frame 300 can include four (4) bits for the MCS index of the first stream, four (4) bits for the MCS of the second stream, four (4) bits for the MCS of the third stream, and four (4) bits for the MCS of the fourth stream. Thus, the UL-MCS subfield can need a total of 16 bits to indicate all MCS index combinations for the streams in up to 4 UL streams. The MCS indexes can be included in the trigger frame as multiple subfields in each user info field 312' or as multiple sub-subfields in, for example, the trigger related user info subfield 358.

[0154] In the above embodiments, the MCS table is defined for each STA in terms of a contiguous number of streams (i.e., one allocated stream, two allocated streams,... L allocated streams). In some embodiments, the MCS table is defined for each STA in terms of any suitable number of streams, which does not necessarily start with one allocated stream and / or which does not necessarily consist of a contiguous number of streams. For example, in one embodiment, the MCS table is defined for each STA in terms of one allocated stream, two allocated streams, and four allocated streams (L = 3). In another example, the MCS table is defined for each STA in terms of two allocated streams, three allocated streams, and four allocated streams (L = 3).

[0155] In the above example, the last two bits B30 and B31 of the SS Allocation / RA-RU Information subfield 352 can be used to store i (indicating the number of allocated streams to the STA 112 and the corresponding MCS table). In other embodiments, other bits of the SS Allocation / RA-RU Information subfield 352 can be used to store i (indicating the number of allocated streams to the STA 112 and the corresponding MCS table).

[0156] Figure 8 is a flowchart illustrating a notification procedure 400 performed by the AP 102 (or more specifically, at least one processing unit 142 of the AP 102) for notifying a plurality of STAs 112 of their allocated streams and corresponding MCS indices. After the procedure 400 starts (step 402), the AP 102 generates the trigger frame 300 with the indication of the number of allocated streams to each STA 112 and the indication of the corresponding MCS indices (step 404). As described above, the trigger frame 300 includes the user info field 312' of each STA 112, which is identified by the unique AID 12 subfield 342 of the STA 112. In the user info field 312' of each STA 112, the last two bits of the SS Allocation / RA-RU Information subfield 352 are used to indicate the number of allocated streams to the STA 112 and the corresponding MCS table, and the 4-bit UL MCS subfield 348 (and / or other subfields / subsubfields as described above) are used to store j (indicating the MCS indices of the allocated streams).

[0157] In step 406, the AP 102 transmits the trigger frame to the plurality of STAs 112. Then, the notification procedure 400 ends (step 408).

[0158] Figure 9is a flowchart showing a flow 440 of establishing UL communication with the AP 102 using allocation streams by the STA 112. After the flow 440 starts (step 442), the STA 112 receives the trigger frame 300 sent from the AP 102 as described above to obtain the number of allocation streams and the corresponding MCS indices (step 444). More specifically, the STA 112 identifies the user info field 312' of the trigger frame 300 using its unique AID 12, and then obtains the MCS table number from the last two bits of the SS Allocation / RA-RU info subfield 352 (and thus the number of streams allocated to the STA 112). Then, the MCS table to be used is determined. The STA 112 also retrieves the MCS set index from the 4-bit UL MCS subfield 348 (and / or other subfields / subsubfields as described above). Then, the STA retrieves the MCS indices from the determined MCS table (stored in its memory).

[0159] As can be appreciated by those skilled in the art, each MCS index represents a set of communication parameters. In step 446, the STA 112 transmits signals to the AP 102 using the allocation streams, where the parameters of each stream are defined by the corresponding MCS index. Then, the flow 440 ends (step 448).

[0160] Figure 10 and Figure 11 is a graph showing some simulation results obtained using the following simulation settings:

[0161] • 6x8 UL MU-MIMO (the AP has eight (8) antennas, three (3) STAs are scheduled for UL MU-MIMO, and each STA is allocated with two streams (thus, there are six (6) streams in total));

[0162] • IEEE High Throughput Task Group (TGn) channel model D for UL;

[0163] • MCS indices per stream:

[0164] - STA 0: MCS7-MCS5, STA1: MCS5-MCS3, STA2: MCS3-MCS1;

[0165] • MCS per STA:

[0166] - STA 0: MCS5-MCS5, STA1: MCS3-MCS3, STA2: MCS1-MCS1

[0167] o coincides with the worst MCS

[0168] •

[0169] - N BPSC A: number of bits per subcarrier of the first stream

[0170] - N BPSC B: number of bits per subcarrier of the second stream

[0171] - Coderate A: code rate of the first stream

[0172] - Coderate B: code rate of the second stream

[0173] - N BPSC A: number of bits per subcarrier of the first stream : total number of data subcarriers

[0174] - BW: bandwidth

[0175] • Minimum mean squared error (MMSE) detection is used.

[0176] Figure 10 is a plot showing PER comparison between per-stream MCS and per-STA MCS for UL MU-MIMO of three (3) STAs, where each STA has two streams.

[0177] Figure 11 is a plot showing effective throughput comparison between per-stream MCS and per-STA MCS for UL MU-MIMO of three (3) STAs, where each STA has two streams.

[0178] In the above embodiments, a stream-based MCS allocation method is used to allocate or otherwise assign an MCS index to each UL stream of a STA 112. In some embodiments, the trigger frame 300 is used to inform the STA of the UL stream allocated to the STA and the corresponding MCS index. In some embodiments, the notification or indication of the allocated stream and corresponding MCS index is embedded in the user info field 312' for each STA 112. In some embodiments, multiple pre-defined MCS tables are used, each including multiple MCS sets. The number of allocated streams (and corresponding MCS table number) is stored in the SS allocation / RA-RU info subfield 352 of the user info field 312' of the STA, and the MCS set index is stored in the UL MCS subfield 348 of the user info field 312' of the STA and / or other locations (e.g., the reserved subfield 350, the reserved subfield 356, and / or the trigger-related user info subfield 358).

[0179] In some embodiments, the encoding of each UL stream is based on multiple codewords. In other words, the signal transmitted via each stream is independently encoded and / or interleaved from the signals transmitted via other streams.

[0180] In some embodiments, the MCS indices in the MCS set are arranged in descending order as the stream index increases.

[0181] In the above embodiments, the flow-based MCS allocation and indication method is used for UL MU-MIMO. In some embodiments, the flow-based MCS allocation and indication method can be used for UL SU-MIMO.

[0182] In some embodiments, the stream-based MCS allocation and indication method can be used for DL ​​SU-MIMO and / or DL ​​MU-MIMO, wherein the number of allocated streams and the indication of the MCS index can be stored in the signal (SIG) field of the PPDU (e.g., U-SIG or EHT-SIG field).

[0183] For example, such as Figure 12 As shown, the EHT PPDU 500 includes the following fields:

[0184] • L-STF field 502 (non-HT short training field);

[0185] • L-LTF field 504 (non-HT long training field);

[0186] • L-SIG field 506 (non-HT signal field);

[0187] • RL-SIG field 508 (repeated non-HT signal field);

[0188] •U-SIG field 510 (General Signal Field);

[0189] • EHT-SIG field 512 (EHT signal field);

[0190] • EHT-STF field 514 (EHT short training field);

[0191] • EHT-LTF field 516 (EHT long training field);

[0192] • EHT-Data field 518 (data field carrying PSDU); and

[0193] • PE field 520 (Grouping Extension Field).

[0194] For MU PPDU, EHT-SIG field 512 includes common fields and several user-specific fields. For SU PPDU, EHT-SIG field 512 includes common fields but does not include any user-specific fields.

[0195] Accordingly, in some embodiments, the indication of the number of allocated streams and MCS indices described above can be stored in a user-specific field of the EHT-SIG field 512 of the PPDU 500 (e.g., for DL MU-MIMO), and / or can be stored in a common field of the EHT-SIG field 512 of the PPDU 500 (e.g., for DL SU-MIMO).

[0196] In some embodiments, for DL SU-MIMO and / or DL MU-MIMO, any suitable SIG field or suitable combination of SIG fields of a PPDU (e.g., the PPDU 500 described above or other types of PPDUs) can be used to store the indication of the number of allocated streams and MCS indices described above.

[0197] In these embodiments, when a MCS index is also allocated for each stream in a DL SU / MU-MIMO transmission, multi-codeword based encoding and interleaving can be needed.

[0198] In conventional approaches, a STA can have to adapt to the worst stream in the allocated streams, and waste the capacity of other better streams. In contrast to conventional approaches, the stream-based MCS allocation and indication methods disclosed herein enable APs and STAs to communicate with each other via multiple streams, where the communication parameters (represented by MCS indices) are adapted to the characteristics of the streams, thereby better utilizing the streams. Accordingly, the communication performance achieved by the stream-based MCS allocation and indication methods disclosed herein is improved.

[0199] C. Abbreviation Table

[0200]

[0201] While embodiments have been described above with reference to the drawings, it will be appreciated that variations and modifications can be made without departing from the scope of the claims as defined below.

Claims

1. A multiple-input multiple-output (MIMO) communication method, comprising: Generate signaling for one or more devices; as well as Send the signaling to the one or more devices; For each of the one or more devices, the signaling is used to indicate multiple streams allocated to the device and multiple modulation and coding system (MCS) indices, each MCS index corresponding to one of the multiple streams.

2. The MIMO communication method according to claim 1, characterized in that, The one or more devices are one or more stations (STAs).

3. The MIMO communication method according to claim 1 or 2, characterized in that, The signaling includes a first instruction and a second instruction for each of the one or more devices; Wherein, for each of the one or more devices, the first indication is used to indicate multiple streams allocated to the device, and the second indication is used to indicate multiple modulation and coding system (MCS) indices, each MCS index corresponding to one of the multiple streams.

4. The MIMO communication method according to claim 3, characterized in that, The signaling is carried in a trigger frame for uplink (UL) MIMO communication; The trigger frame includes a user information field for each device; and The first indication and the second indication for each device are stored in the corresponding user information field of the trigger frame.

5. The MIMO communication method according to claim 4, characterized in that, The signaling is carried in trigger frames for uplink (UL) multi-user MIMO (MU-MIMO) communication or for UL single-user MIMO (SU-MIMO) communication.

6. The MIMO communication method according to claim 4 or 5, characterized in that, The first instruction further indicates an MCS table comprising multiple MCS sets, each MCS set including multiple entries representing multiple candidate MCS indices of the multiple streams, and the second instruction includes an MCS set index for indicating one of the multiple MCS sets.

7. The MIMO communication method according to claim 6, characterized in that, The MCS table is one of multiple candidate MCS tables. Among them, the plurality of candidate MCS tables include a single-stream MCS table; and Each MCS set in the single-stream MCS table includes a corresponding MCS index in addition to the MCS index for the Dup mode.

8. The MIMO communication method according to claim 6 or 7, characterized in that, The candidate MCS indices of each MCS set are arranged in non-ascending or descending order as the indices of the multiple streams increase.

9. The MIMO communication method according to any one of claims 6 to 8, characterized in that, The plurality of items in each MCS set are the plurality of candidate MCS indices of the MCS set; Wherein, each MCS set includes a plurality of items comprising a base candidate MCS index and one or more index differences relative to the base candidate MCS index; or Each MCS set includes a base candidate MCS index and one or more index differences relative to the base candidate MCS index and neighboring candidate MCS indices.

10. The MIMO communication method according to claim 4 or 5, characterized in that, The second indication includes the plurality of candidate MCS indices.

11. The MIMO communication method according to any one of claims 4 to 10, characterized in that, The first and second indications for each device are stored together with a unique identifier (ID) in the user information field of the trigger frame.

12. The MIMO communication method according to any one of claims 4 to 11, characterized in that, The first indication is stored in the spatial stream (SS) allocation / RA-RU information subfield of the user information field, and the second indication is stored in one or more of the UL MCS subfield, the first reserved subfield, the second reserved subfield, and the trigger-related user information subfield of the user information field.

13. The MIMO communication method according to claim 12, characterized in that, The first indication is stored in the last two bits of the SS allocation / RA-RU information subfield of the user information field, and the second indication is stored in the UL MCS subfield of the user information field.

14. The MIMO communication method according to claim 3, characterized in that, The signaling is carried in a physical layer protocol data unit (PPDU) for downlink (DL) MIMO communication; and The first indication and the second indication for each device are stored in one or more signal (SIG) fields of the PPDU.

15. The MIMO communication method according to claim 14, characterized in that, The one or more SIG fields of the PPDU include one or more of the L-SIG field, RL-SIG field, U-SIG field and EHT-SIG field.

16. The MIMO communication method according to claim 14, characterized in that, The one or more SIG fields of the PPDU include the EHT-SIG field; and Specifically, for DL ​​MU-MIMO, the first indication and the second indication for each device are stored in one or more user-specific fields of the EHT-SIG field, or for DL ​​SU-MIMO, the first indication and the second indication for each device are stored in one or more common fields of the EHT-SIG field.

17. One or more circuits for performing the method according to any one of claims 1 to 16.

18. One or more non-transitory computer-readable storage devices, comprising computer-executable instructions, characterized in that, When the instructions are executed, they cause one or more circuits to perform the method according to any one of claims 1 to 16.

19. A MIMO communication method, comprising: Receive signaling from the device to obtain multiple streams and multiple MCS indices corresponding to the multiple streams; as well as Multiple signals are sent to the device using the multiple streams, wherein the parameters of each stream are defined by a corresponding MCS index among the multiple MCS indices.

20. The MIMO communication method according to claim 19, characterized in that, The MIMO communication method is executed by the STA.

21. The MIMO communication method according to claim 19 or 20, characterized in that, The device is an access point (AP).

22. The MIMO communication method according to any one of claims 19 to 21, characterized in that, The signaling includes a first indication for indicating the plurality of flows and a second indication for indicating the plurality of MCS indices.

23. The MIMO communication method according to claim 22, characterized in that, The signaling is carried in a trigger frame for UL MIMO communication; and The first indication and the second indication are stored in the user information field of the trigger frame.

24. The MIMO communication method according to claim 23, characterized in that, The signaling is carried in a trigger frame for UL MU-MIMO communication or UL SU-MIMO communication.

25. The MIMO communication method according to claim 23 or 24, characterized in that, The first instruction further indicates an MCS table comprising multiple MCS sets, each MCS set including multiple entries representing multiple candidate MCS indices of the multiple streams, and the second instruction includes an MCS set index for indicating one of the multiple MCS sets.

26. The MIMO communication method according to claim 25, characterized in that, The MCS table is one of multiple candidate MCS tables. Among them, the plurality of candidate MCS tables include a single-stream MCS table; and Each MCS set in the single-stream MCS table includes a corresponding MCS index in addition to the MCS index for the Dup mode.

27. The MIMO communication method according to claim 25 or 26, characterized in that, The candidate MCS indices of each MCS set are arranged in non-ascending or descending order as the indices of the multiple streams increase.

28. The MIMO communication method according to any one of claims 25 to 27, characterized in that, The plurality of items in each MCS set are the plurality of candidate MCS indices of the MCS set; Wherein, each MCS set includes a plurality of items comprising a base candidate MCS index and one or more index differences relative to the base candidate MCS index; or Each MCS set includes a base candidate MCS index and one or more index differences relative to the base candidate MCS index and neighboring candidate MCS indices.

29. The MIMO communication method according to claim 23 or 24, characterized in that, The second indication includes the plurality of candidate MCS indices.

30. The MIMO communication method according to any one of claims 23 to 29, characterized in that, The first and second indications for each device are stored together with a unique ID in the user information field of the trigger frame.

31. The MIMO communication method according to any one of claims 23 to 30, characterized in that, The first indication is stored in the SS allocation / RA-RU information subfield of the user information field, and the second indication is stored in one or more of the UL MCS subfield, the first reserved subfield, the second reserved subfield, and the trigger-related user information subfield of the user information field.

32. The MIMO communication method according to claim 31, characterized in that, The first indication is stored in the last two bits of the SS allocation / RA-RU information subfield of the user information field, and the second indication is stored in the UL MCS subfield of the user information field.

33. The MIMO communication method according to claim 22, characterized in that, The signaling is carried in a PPDU used for DL ​​MIMO communication; and The first indication and the second indication are stored in one or more SIG fields of the PPDU.

34. The MIMO communication method according to claim 33, characterized in that, The one or more SIG fields of the PPDU include one or more of the L-SIG field, RL-SIG field, U-SIG field and EHT-SIG field.

35. The MIMO communication method according to claim 33, characterized in that, The one or more SIG fields of the PPDU include the EHT-SIG field; and for DL ​​MU-MIMO, the first indication and the second indication for each device are stored in one or more user-specific fields of the EHT-SIG field, or for DL ​​SU-MIMO, the first indication and the second indication for each device are stored in one or more common fields of the EHT-SIG field.

36. The MIMO communication method according to any one of claims 19 to 35, characterized in that, The signals transmitted via each stream are encoded and / or interleaved independently of the signals transmitted via other streams.

37. One or more circuits, characterized in that, Used to perform the method according to any one of claims 19 to 36.

38. One or more non-transitory computer-readable storage devices, comprising computer-executable instructions, wherein, When the instructions are executed, they cause one or more circuits to perform the method according to any one of claims 19 to 36.

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