Reduced Feedback Channel Sounding for Next Generation WiFi
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Solution Overview
Problem
The large size of feedback data in channel sounding procedures for next-generation WiFi, particularly with wider bandwidth and higher-order MIMO schemes, leads to inefficiencies and increased overhead, limiting the number of stations that can transmit feedback simultaneously and requiring more frequent updates.
Innovation Solution
Implementing reduced feedback methods such as antenna selection, wideband precoding, and a combination of wideband and narrowband precoders to decrease the size of the feedback data, allowing stations to select a subset of antennas or calculate a single precoding vector for multiple tones, thereby reducing the overall feedback size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If wider bandwidth and higher-order MIMO schemes are implemented, then peak throughput is improved, but feedback size increases significantly
Solution Approach 1:
The patent segments the feedback transmission by dividing stations into multiple groups. Each group transmits feedback in separate resource occasions, preventing the need to transmit all feedback data simultaneously. This segmentation approach allows the system to support wider bandwidth and higher-order MIMO schemes by managing the large feedback size through time-division multiplexing of feedback transmissions.
2Loss of information
If feedback size increases, then more channel information is available, but system efficiency decreases due to increased overhead
Solution Approach 1:
The patent implements periodic feedback transmission where stations transmit feedback in periodic resource occasions rather than continuously. This periodic action allows the system to maintain complete channel information while reducing instantaneous overhead by spreading feedback transmissions across multiple time instances, thereby improving system efficiency.
3Adaptability or versatility
If feedback size increases, then more stations can be supported, but the number of stations that can transmit simultaneously decreases
Solution Approach 1:
The patent segments the set of stations into multiple groups, where each group transmits feedback in separate resource occasions. This segmentation enables the system to support a larger total number of stations by distributing feedback transmissions across multiple time instances, effectively increasing the overall feedback capacity while managing the limited simultaneous transmission capability.
4Measurement precision
If feedback transmission is performed more frequently, then channel accuracy is improved, but overhead increases
Solution Approach 1:
The patent implements periodic feedback transmission at optimized intervals that balance channel accuracy requirements with overhead constraints. By using periodic action rather than continuous or overly frequent feedback transmissions, the system maintains adequate channel accuracy while minimizing the time and resources consumed by feedback overhead.
Data Source
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AI summary
The present invention relates to a channel sounding procedure, particularly a reduced feedback channel sounding procedure for next generation WiFi. To this end, the invention proposes a transmitting device and a receiving device, both configured to support reduced feedback in a channel sounding procedure. The transmitting device is configured to: select at least one of a plurality of feedback types; determine, and send to a receiving device, a feedback indication format, wherein the feedback indication format comprises the selected at least one feedback type and a feedback dependent field based on the selected feedback type; and obtain feedback data from the receiving device, wherein the feedback data bases on the determined feedback indication format sent to the receiving device.