Selective Beamforming Matrix for WLAN Feedback Overhead Reduction
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Solution Overview
Problem
In wireless local area networks (WLANs), the increase in the number of stations (STAs) leads to higher feedback overhead due to the need for communication between access points (APs) and STAs, which complicates the feedback information generation and beamforming matrix determination processes.
Innovation Solution
A method and apparatus that determine a beamforming matrix regardless of channel information, allowing for the transmission of a beamforming training (BF-T) frame, which reduces feedback overhead by allocating frequency units based on reception strength feedback from STAs, thereby simplifying the feedback and beamforming processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of transmit antennas of a communication apparatus and the number of receive antennas of a station are increased, then the communication capacity and beamforming performance are improved, but the feedback overhead increases significantly
Solution Approach 1:
The patent extracts only the essential feedback information (reception strength) needed for beamforming optimization, removing unnecessary detailed channel state information feedback. This allows the system to maintain high communication capacity with multiple antennas while significantly reducing the feedback overhead by transmitting only the most critical performance metric.
Solution Approach 2:
The patent changes the feedback parameter from detailed channel matrices to simplified reception strength values. By transforming the feedback information into a more compact parameter representation, the system can support increased antenna counts without proportionally increasing feedback overhead, thus resolving the contradiction between communication capacity and feedback burden.
2Measurement precision
If channel information is used to determine beamforming matrices, then the beamforming accuracy is improved, but the complexity of feedback information generation and processing increases
Solution Approach 1:
The patent introduces reception strength as an intermediary parameter that mediates between the complex channel information and the beamforming matrix determination. Instead of directly using detailed channel matrices, the system uses reception strength measurements as a simplified intermediary that preserves beamforming accuracy while dramatically reducing processing complexity at both the station and access point.
3Manufacturing precision
If detailed channel matrices are fed back from stations to the access point, then the beamforming matrix determination accuracy is improved, but the feedback overhead and processing time increase
Solution Approach 1:
The patent uses simple reception strength measurements instead of complex channel matrices, analogous to using a simple, inexpensive proxy rather than a complex, expensive measurement. This disposable, simplified feedback approach maintains sufficient beamforming accuracy while dramatically reducing the time and computational resources required for feedback processing.
Data Source
AI summary
Disclosed are a frame transmission method using a selective beamforming and a communication apparatus to perform the frame transmission method. The communication apparatus may determine a beamforming matrix based on classification information in which a plurality of subcarriers used for communication is classified into a plurality of frequency units, may map a long training field (LTF) sequence to the beamforming matrix, and transmit a beamforming training (BF-T) frame including the mapped LTF sequence to a plurality of stations, may receive, from the plurality of stations having receiving the BF-T frame, feedback information generated based on a reception strength of the BF-T frame, and may allocate frequency units to data frames to be transmitted to the plurality of stations based on the feedback information, and transmit the data frames using the allocated frequency units. The reception strength of the BF-T frame may be determined at each station for each frequency unit.