MIMO Link Adaptation Feedback Compression
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Solution Overview
Problem
Existing MIMO systems face challenges in reducing the amount of feedback information required for link adaptation, which can strain communication capacities.
Innovation Solution
The proposed solution involves a transmitting apparatus and receiving apparatus that utilize feedback information indicating communication capacity and stream ratios to determine coding rates and modulation schemes for each stream, reducing the overall amount of feedback needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If detailed stream-level channel information is fed back for link adaptation, then transmission reliability is improved, but the amount of feedback information increases excessively
Solution Approach 1:
The patent combines multiple stream-level channel quality indicators into a single aggregated channel quality indicator. Instead of feeding back separate CQI values for each stream, the system merges them into one comprehensive indicator that represents the overall channel condition, thereby reducing feedback overhead while maintaining the ability to perform reliable link adaptation across all streams
Solution Approach 2:
The aggregated channel quality indicator serves multiple functions simultaneously: it represents the overall channel condition for link adaptation, enables spatial multiplexing decisions, and provides a basis for determining modulation and coding schemes for multiple streams. This multi-functionality eliminates the need for separate feedback mechanisms for each function, reducing the total feedback information required
Data Source
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AI summary
A link adaptation method and others wherein feedback information amount can be reduced. According to this method, a receiving apparatus (100) calculates, based on a channel matrix, a capacity (C) and a stream ratio (r) that is a ratio of the reception qualities of streams, and then transmits, as feedback information, the calculated capacity (C) and stream ratio (r) to a transmitting apparatus. In the transmitting apparatus (200), the number of transmittable streams, the modulation scheme and the fed-back capacity (C) are used to calculate the encoding ratio (R) and sequence length (S)ofspatialmultiplexedsymbols. Then, the modulation scheme (M1-Mn) of each stream is decided based on the fed-back stream ratio (r) and the sequence length (S) of spatial multiplexed symbols.