Cross-Band Beamforming Training for mmWave WLAN
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Solution Overview
Problem
Existing wireless LAN systems face challenges in efficiently performing beamforming training procedures, particularly in millimeter wave (mmWave) bands, which affect data rate and latency.
Innovation Solution
A method and device for performing sector level sweep (SLS) and beam refinement protocol (BRP) procedures are introduced to optimize beamforming training in mmWave bands, involving information exchange and feedback mechanisms between stations (STAs) in different frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If beamforming training procedure is performed in mmWave band, then data rate is improved, but latency increases
Solution Approach 1:
The beamforming training procedure is divided into two separate frequency bands: sector sweep operations are performed in the mmWave band (second operating frequency band) to establish directional beams, while feedback and control signaling are exchanged in the sub-7 GHz band (first operating frequency band). This segmentation allows the high-data-rate benefits of mmWave to be realized while avoiding the latency penalty of performing all training operations in mmWave, as the lower-frequency band provides more reliable and faster control signal exchange.
2Reliability
If sector sweep operation is performed in mmWave band, then transmission reliability is improved, but device complexity increases
Solution Approach 1:
The sub-7 GHz frequency band serves as an intermediary for control and feedback operations. The first operating frequency band (sub-7 GHz) acts as a mediator that handles the exchange of feedback frames and response frames, while the second operating frequency band (mmWave) is dedicated to sector sweep operations. This intermediary approach simplifies device complexity by offloading complex control signaling to a more stable frequency band while maintaining the reliability benefits of mmWave for actual data transmission.
Data Source
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AI summary
Disclosed are a method and device for performing a beamforming training procedure considering a millimeter wave band in a WLAN system. A method performed by a first STA in a WLAN system according to the present invention may comprise the steps of: in a first operation frequency band, checking information related to the initiation of a sector sweep operation in a second operation band; in the second operation frequency band, measuring the best transmission sector of a second STA, on the basis of receiving a plurality of frames for the sector sweep operation from the second STA, and performing a reception sector sweep of the first STA; in the first operation frequency band, transmitting a feedback frame including identification information about the best transmission sector to the second STA; and in the first operation frequency band, receiving a response frame to the feedback frame from the second STA.