Beamforming Feedback Reduction via Angle Indices and Steering Matrix
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Solution Overview
Problem
Next-generation WLAN systems require significant signaling and resources for beamforming, which needs to be reduced to enhance efficiency and performance.
Innovation Solution
The solution involves a method where a first apparatus in a WLAN transmits a null data packet to a second apparatus, generating a channel estimate, decomposing it to obtain a feedback matrix, and using this matrix to derive beamforming information, including angle indices and a steering matrix index, to facilitate efficient beamforming data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If beamforming is performed using traditional feedback methods in next-generation WLAN systems, then communication performance is improved, but signaling overhead and resource consumption increase significantly
Solution Approach 1:
The patent extracts only the essential beamforming feedback information (angle indices and steering matrix index) from the complete channel state information, transmitting only what is necessary for beamforming operations. This selective extraction reduces feedback overhead while maintaining beamforming performance by focusing on the most critical parameters needed for spatial direction identification.
Solution Approach 2:
The patent transforms the continuous channel state information into discrete parameters (angle indices and steering matrix indices) through quantization and codebook mapping. This parameter transformation reduces the amount of data that needs to be transmitted and processed, thereby reducing signaling overhead while preserving the essential beamforming capabilities.
2Measurement precision
If detailed channel state information is transmitted for beamforming, then beamforming accuracy is improved, but resource consumption and processing complexity increase
Solution Approach 1:
The patent segments the beamforming feedback information into two distinct components: angle indices (indicating spatial directions) and steering matrix indices (indicating precoding configurations). This segmentation allows the system to transmit only the necessary discrete parameters rather than continuous channel state information, reducing data volume while maintaining beamforming accuracy through the structured codebook approach.
Solution Approach 2:
The patent uses codebooks that are pre-stored at both the transmitting and receiving ends, containing representative channel state information patterns. Instead of transmitting the actual measured channel state, the system transmits indices that reference corresponding entries in the pre-shared codebooks. This copying approach significantly reduces data transmission volume while ensuring both ends have access to the same reference information for accurate beamforming.
Data Source
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AI summary
A second apparatus configured to communicate with a first apparatus in a wireless local area network (WLAN), including: a transceiver; and at least one processor configured to: receive, using the transceiver, a null data packet (NDP) from the first apparatus, generate a channel estimate based on the NDP, decompose the channel estimate to obtain a feedback matrix, based on the feedback matrix, obtain beamforming information to be used by the first apparatus to perform beamforming, transmit, using the transceiver, the beamforming information to the first apparatus, and receive, using the transceiver, a data transmission which is beamformed by the first apparatus based on the beamforming information, wherein the beamforming information includes at least one from among: a pair of angle indices which indicate a pair of angle vectors to be used by the first apparatus to beamform the data transmission, and a steering matrix index which indicates a steering matrix to be used by the first apparatus to beamform the data transmission.