CQI Signaling in Multi-Beam MIMO Systems
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Solution Overview
Problem
In multi-beam MIMO systems, the existing methods face a high signaling load for channel quality information (CQI) due to the need to transmit multiple CQI values for varying numbers of beams, which increases overhead without significantly degrading system performance.
Innovation Solution
The method involves transmitting multiple sequences of CQI values, each derived based on assumptions about the number of simultaneously transmitted beams, with at least one transmission parameter set to a lower value in sequences indicating simultaneous beam transmission, thereby reducing signaling overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple CQI values are transmitted for varying numbers of beams, then the transmission rate control accuracy is improved, but the signaling load increases
Solution Approach 1:
The CQI values are segmented into multiple sequences, where each sequence corresponds to a specific number of simultaneously transmitted beams. Instead of transmitting all possible CQI values for all beam combinations, the system divides the CQI reporting into separate sequences (first sequence for one beam, second sequence for two beams, etc.), reducing the overall signaling load while maintaining accurate rate control for each beam configuration
Solution Approach 2:
The system dynamically selects which CQI sequence to transmit based on the actual number of beams being transmitted. The mobile station determines the current beam configuration and transmits only the relevant CQI sequence, making the signaling adaptive to the current system state rather than always transmitting maximum CQI information
2Measurement precision
If multiple sequences of CQI values are transmitted for different beam combinations, then the transmission rate control is improved, but the energy expenditure increases
Solution Approach 1:
Instead of transmitting all possible CQI sequences for all beam combinations, the system transmits only the partial set of CQI sequences that are currently needed based on the actual number of beams transmitted. This partial action approach reduces energy expenditure while maintaining sufficient control accuracy for the active beam configuration
Data Source
Figure 1~3
AI summary
The present invention relates to the signaling of channel quality information in a multi-beam transmission system, wherein a plurality of sets of channel quality information are transmitted for controlling the transmission rate on one of the beams, wherein each set of channel quality information is derived dependent on an assumed parameter of at least one other beam which could be transmitted, comprising selecting a parameter of the transmission of each of the sets of channel quality information dependent on the assumed parameter of the at least one other beam.