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US-20260129700-A1 - MULTI-LINK OPERATION ASSISTED BEAM REFINEMENT PROTOCOL FOR MMWAVE LINK

US20260129700A1US 20260129700 A1US20260129700 A1US 20260129700A1US-20260129700-A1

Abstract

A wireless communication method, system, and apparatus are provided to perform analog beamforming training with beam tracking for slow channel changes or beam refinement by generating beam refinement training control information regarding a mmWave link between a beamforming training initiator and responder, where the initiator transmits a training PPDU sequence to the responder through the mmWave link under control of the beam refinement training control information, and then receives a signal quality feedback message with a first signal quality measure from the responder through the mmWave link or non-mmWave link in response to the responder detecting and measuring the training PPDU sequence under control of the beam refinement training control information, where the initiator uses the signal quality measure to perform beam tracking and refinement to the established mmWave link by determining the transmit AWV or beam ranking for analog beamforming training of the initiator.

Inventors

  • XIAYU ZHENG
  • Liwen Chu
  • Rui Cao
  • Hongyuan Zhang

Assignees

  • NXP USA, INC.

Dates

Publication Date
20260507
Application Date
20251021

Claims (20)

  1. 1 . A wireless communication method for performing analog beamforming training with beam tracking for slow channel changes or beam refinement by a first wireless multi-link device (MLD) in accordance with Institute of Electrical and Electronics Engineers (IEEE) 802.11 protocol, comprising: generating beam refinement training control information regarding an established millimeter wave (mmWave) link between the first wireless MLD and a second wireless MLD, where the beam refinement training control information comprises a first indicator of a transmit/receive beam reciprocity value for the first and second wireless MLDs, a second indicator identifying which of the first or second wireless MLD is an initiator, and a third indicator specifying a training parameter comprising a training field configuration; transmitting, by the first wireless MLD, a first beam refinement training PPDU sequence to the second wireless MLD through the mmWave link under control of the beam refinement training control information; and receiving, by the first wireless MLD, a first signal quality feedback message from the second wireless MLD through the mmWave link or a non-mmWave link in response to the second wireless MLD detecting and measuring a first signal quality measure based on the first beam refinement training PPDU sequence received by the second wireless MLD under control of the beam refinement training control information, where the first wireless MLD uses the first signal quality measure to perform beam tracking and refinement to the established mmWave link by determining the transmit antenna weight vectors (AWV) or beam ranking for analog beamforming of the first wireless MLD.
  2. 2 . The wireless communication method of claim 1 , further comprising: receiving, by the first wireless MLD, a second beam refinement training PPDU sequence from the second wireless MLD through the mmWave link under control of the beam refinement training control information where the first indicator signals there is no transmit/receive beam reciprocity between the first and second wireless MLDs; measuring, by the first wireless MLD, a second signal quality measure based on the second beam refinement training PPDU sequence received by the first wireless MLD; and transmitting, by the first wireless MLD, a second signal quality feedback message to the second wireless MLD through the mmWave link or non-mmWave link which includes the second signal quality measure for use by the second wireless MLD to determine transmit antenna weight vectors (AWV) or beam ranking for analog beamforming of the second wireless MLD.
  3. 3 . The wireless communication method of claim 2 , where the first wireless MLD receives the second beam refinement training PPDU sequence from the second wireless MLD through the mmWave link a predefined Interframe space (IFS) after transmitting the first beam refinement training PPDU sequence.
  4. 4 . The wireless communication method of claim 2 , where the first wireless MLD receives the second beam refinement training PPDU sequence from the second wireless MLD through the mmWave link after the first wireless MLD performs an announcement frame exchange with the second wireless MLD.
  5. 5 . The wireless communication method of claim 1 , where generating the beam refinement training control information comprises: transmitting, by the first wireless MLD, a first control/management frame regarding the mmWave link to the second wireless MLD through the non-mmWave link between the first wireless MLD and the second wireless MLD; and receiving, by the first wireless MLD, a second control/management response frame sent by the second wireless MLD through the non-mmWave link, where information contained in the first control/management frame and second control/management response frame are used to specify a best available transmit/receive AWV or beam pair for the first wireless MLD and second wireless MLD.
  6. 6 . The wireless communication method of claim 5 , where generating the beam refinement training control information comprises: transmitting, by the first wireless MLD, a first announcement frame regarding the mmWave link to the second wireless MLD through the mmWave link between the first wireless MLD and the second wireless MLD; and receiving, by the first wireless MLD, a second announcement response frame sent by the second wireless MLD through the mmWave link, where information contained in the first announcement frame and second announcement response frame are used to specify a plurality of beam refinement training parameters comprising a number of transmit/receive beams and one or more training field configurations for use in generating the first beam refinement training PPDU sequence.
  7. 7 . The wireless communication method of claim 1 , where generating the beam refinement training control information comprises: transmitting, by the first wireless MLD, a first announcement frame regarding the mmWave link to the second wireless MLD through the non-mmWave link between the first wireless MLD and the second wireless MLD; and receiving, by the first wireless MLD, a second announcement response frame sent by the second wireless MLD through the non-mmWave link, where information contained in the first announcement frame and second announcement response frame are used to specify a plurality of beam refinement training parameters comprising a best available transmit/receive AWV pair for the first wireless MLD and second wireless MLD, a number of transmit/receive beams, and a one or more training field configurations for use in generating the first beam refinement training PPDU sequence.
  8. 8 . The wireless communication method of claim 1 , where generating the beam refinement training control information comprises negotiating a best available transmit/receive AWV pair between the first wireless MLD and second wireless MLD for use in transmitting the first beam refinement training PPDU sequence and receiving the first signal quality feedback message by the first wireless MLD, and in receiving the first beam refinement training PPDU sequence and transmitting the first signal quality feedback message by the second wireless MLD.
  9. 9 . The wireless communication method of claim 1 , where the first wireless MLD transmits the first beam refinement training PPDU sequence after waiting for a specified time delay after an announcement frame exchange between the first wireless MLD and second wireless MLD.
  10. 10 . The wireless communication method of claim 9 , where the specified time delay may be a predefined Interframe space (IFS) or a medium access time with random backoff based on medium status if the announcement frame exchange is on the non-mmWave link.
  11. 11 . The wireless communication method of claim 9 , where the specified time delay may be a Short Interframe space (SIFS) if the announcement frame exchange is on the mmWave link.
  12. 12 . The wireless communication method of claim 1 , wherein each training PPDU in the first beam refinement training PPDU sequence comprises one or more non-training fields and one or more training fields, and where the first wireless MLD transmits the first beam refinement training PPDU sequence by applying a same or different transmit AWV to each of the one or more training fields.
  13. 13 . The wireless communication method of claim 12 , wherein the one or more training fields may be configured to specify a joint beam tracking/refinement training procedure for both transmit and receive AWVs, a transmit beam refinement training procedure for the first wireless MLD where the second wireless MLD applies a best AWV at a receiver, and a receive beam refinement training procedure for the second wireless MLD where the first wireless MLD applies a best AWV at a transmitter.
  14. 14 . The wireless communication method of claim 13 , wherein the joint beam tracking/refinement training procedure has a first training period configuration and where the transmit beam refinement training procedure and the receive beam refinement training procedure have a second training period configuration.
  15. 15 . The wireless communication method of claim 14 , wherein the first training period configuration is different from or the same as the second training period configuration.
  16. 16 . The wireless communication method of claim 12 , wherein the one or more training fields may be configured to enable the first wireless MLD to transmit a plurality of first beam refinement training PPDU sequences to independently train a corresponding plurality of transmit RF chains.
  17. 17 . The wireless communication method of claim 12 , wherein the one or more training fields may be configured to enable the first wireless MLD to transmit a plurality of first beam refinement training PPDU sequences to simultaneously train a corresponding plurality of transmit RF chains, with each RF transmit chain mapped to a single space-time stream by applying spatial expansion with orthogonal waveforms at each training field.
  18. 18 . The wireless communication method of claim 5 , where generating the beam refinement training control information comprises transmitting, by the first wireless MLD, a first announcement frame regarding the mmWave link to the second wireless MLD through the mmWave link between the first wireless MLD and the second wireless MLD if beam refinement training is only used to train transmit beams at the first wireless MLD with a fixed receive beam at the second wireless MLD.
  19. 19 . A wireless multi-link device (MLD) comprising: a plurality of wireless transceivers; memory including operational instructions; and one or more processing modules operably coupled to the plurality of wireless transceivers and the memory, wherein the one or more processing modules are configured to execute the operational instructions to perform analog beamforming training with beam tracking for slow channel changes or beam refinement by: generating beam refinement training control information regarding an established millimeter wave (mmWave) link between the wireless MLD and a second wireless MLD, where the beam refinement training control information comprises a best available transmit/receive AWV pair for the wireless MLD and the second wireless MLD, a number of transmit/receive beams, a training field configuration, transmit/receive beam reciprocity indicator, and information identifying which of the wireless MLD or second wireless MLD is an initiator; transmitting, by the wireless MLD, a first beam refinement training PPDU sequence to the second wireless MLD through the mmWave link under control of the beam refinement training control information; and receiving, by the wireless MLD, a first signal quality feedback message from the second wireless MLD through the mmWave link or non-mmWave link in response to the second wireless MLD detecting and measuring a first signal quality measure based on the first beam refinement training PPDU sequence received by the second wireless MLD under control of the beam refinement training control information, where the wireless MLD uses the first signal quality measure to perform beam tracking and refinement to the established mmWave link by determining the transmit antenna weight vectors (AWV) or beam ranking for analog beamforming of the wireless MLD.
  20. 20 . The wireless MLD of claim 19 , wherein the one or more processing modules are configured to execute the operational instructions to generate the beam refinement training control information by: transmitting, by the wireless MLD, a first setup frame regarding the mmWave link to the second wireless MLD through the non-mmWave link between the wireless MLD and the second wireless MLD; and receiving, by the wireless MLD, a second setup response frame sent by the second wireless MLD through the non-mmWave link, where information contained in the first set frame and second setup response frame are used by the wireless MLD and second wireless MLD to negotiate the beam refinement training control information.

Description

CROSS-REFERENCE TO RELATED APPLICATION AND PRIORITY CLAIM This application claims the benefit of U.S. Provisional Patent Application No. 63/714,936 entitled “MLO Assisted Beam Refinement Protocol for mmWave Link” filed Nov. 1, 2024, which is incorporated by reference in its entirety as if fully set forth herein. BACKGROUND Field The present disclosure is directed in general to communication networks. In one aspect, the present disclosure relates generally to wireless local area network (WLAN) implementing the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard and any other standards and/or networks that can provide wireless transfer of data over a millimeter wave link. Description of the Related Art An ever-increasing number of relatively inexpensive, low power wireless data communication services, networks and devices have been made available over the past number of years, promising near wire speed transmission and reliability. Enabling technology advances in the area of wireless communications, various wireless technology standards (including for example, the IEEE Standards 802.11a/b/g, 802.11n, 802.11ad, 802.11ac, 802.11ax, 802.11ay, and 802.11be and their updates and amendments, as well as the IEEE Standard 802.11bq now in the process of being developed) have been introduced that are known to persons skilled in the art and are collectively incorporated by reference as if set forth fully herein fully. For example, the 802.11be amendment to the IEEE 802.11 standard (“Wi-Fi 7”) added support for Multi-Link Operation (MLO). This feature increases capacity by simultaneously sending and receiving data across different frequency bands and channels (e.g., 2.4 GHz, 5 GHz, and 6 GHz). With MLO, for example, an access point multi-link device (AP MLD) simultaneously establishes multiple links with a non-AP MLD client over more than one frequency band in order to increases throughput, reduce latency, and improve reliability. Multi-Link Operation also supports various operating modes. Another advance with wireless communications was proposed in the 802.11ad, 802.11ay, and 802.11aj standards which defined wireless communication standards in the 60 GHz or 45 GHz (China) mmWave band. In this area, the beamforming with a large number of antennas is identified as one of the most important mechanism in mmWave bands to compensate for the high pathloss for directional multi-gigabit communication (DMG, e.g., see P802.11-REVme/D4.0, August 2023). To balance the trade-off between cost and performance, the implementation of beamforming is composed of both analog beamforming and/or digital beamforming (or hybrid beamforming for MIMO case) for DMG beamforming. In the existing DMG approach for mmWave communication link signaling, there is an initial sector level sweep (SLS) phase to find the transmit and receive antenna weight vectors (AWV) for analog beamforming to enable the AP and STA to communicate, where the AP is the SLS initiator and the SLS is usually conducted periodically based on the beacon interval. In addition, there is a beam refinement protocol (BRP) phase to further train the device's receive and transmit antenna array(s) and improve its transmit (Tx) and receive (Rx) antenna configuration on top of SLS using an iterative procedure with BRP frame. When multiple Tx/Rx RF chains (each connecting to an antenna array) are enabled, the digital beamforming training could be further conducted once the analog beaming with BRP procedure is done and the analog AWVs are applied on both Tx/Rx RF chains. Under the existing DMG approach for mmWave communication link signaling, all the beamforming training packet exchanges are conducted in the mmWave band as a standalone mode. In addition, a special control PHY is required that is defined with 15 dB sensitivity margin over the lowest MCS to assist the training procedure, which also complicates the beamforming protocol design. As seen from the foregoing, there are performance vs. complexity vs. hardware cost trade-offs with the existing DMG approach for mmWave communication link signaling which are non-trivial to solve, and as a result, these standards with the DMG approach are not widely adopted in the market due to the complexity and high cost. BRIEF DESCRIPTION OF THE DRAWINGS The present invention may be understood, and its numerous objects, features and advantages obtained, when the following detailed description of a preferred embodiment is considered in conjunction with the following drawings. FIG. 1 is a simplified block diagram of a multi-link communications system in accordance with selected embodiments of the present disclosure. FIG. 2 is a simplified block diagram of a wireless communications system in accordance with selected embodiments of the present disclosure. FIG. 3 illustrates an example of a frame exchange sequence for an MLO-assisted BRP procedure for an initiator and responder which have TX/RX beam reciprocity and which exchange control f