MU-MIMO Channel Feedback Error Calculation for CQI Accuracy
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Solution Overview
Problem
In MIMO communication systems, the existing methods for feeding back downlink channel feedback information in MU-MIMO transmission mode do not accurately reflect the quality indication errors caused by user parameter differences, leading to suboptimal selection of pre-coding matrices and modulation coding modes, which affects communication performance.
Innovation Solution
A method and apparatus that calculate and include a multi-user channel quality indication error in the downlink channel feedback information, reflecting the difference between MU-MIMO and SU-MIMO transmission modes, allowing for more accurate feedback to the base station, which in turn improves the selection of CQI and modulation coding modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If PMI and CQI are obtained by optimizing for SU-MIMO transmission mode, then the feedback process is simple and compatible with existing standards, but the accuracy of channel quality indication deteriorates in MU-MIMO transmission mode leading to suboptimal pre-coding matrix and modulation coding mode selection
Solution Approach 1:
The patent changes the parameter optimization approach by introducing a new optimization criterion specifically for MU-MIMO transmission mode. Instead of using SU-MIMO optimized PMI and CQI, the system optimizes these parameters considering multi-user interference characteristics, thereby improving channel quality indication accuracy for MU-MIMO while maintaining compatibility with existing feedback structures
Solution Approach 2:
The patent implements dynamic parameter selection by adapting PMI and CQI optimization based on the transmission mode (SU-MIMO or MU-MIMO). The system dynamically adjusts the optimization criteria according to whether single-user or multi-user transmission is being performed, ensuring optimal performance for each mode rather than using a static SU-MIMO based approach
2Device complexity
If downlink channel feedback information does not include multi-user channel quality indication error, then the feedback information structure is simple, but the base station cannot accurately select paired users and determine appropriate modulation coding modes in MU-MIMO transmission
Solution Approach 1:
The patent introduces multi-user channel quality indication error as an intermediary parameter that bridges the gap between simple feedback structures and accurate MU-MIMO transmission. This error metric acts as a mediator that provides the base station with the necessary information to perform accurate user pairing and modulation coding mode selection without requiring complex feedback structures
Solution Approach 2:
The patent enhances the feedback mechanism by including multi-user channel quality indication error in the downlink channel feedback information. This feedback provides the base station with critical information about the accuracy limitations of PMI and CQI in MU-MIMO mode, enabling more reliable user pairing and transmission parameter selection
Data Source
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AI summary
Disclosed are a method and device for feeding back downlink channel feedback information, and a method and device for user matching. The method for feeding back downlink channel feedback information includes: calculating the multi-user channel quality indication error of a user, which error is used to reflect the difference in channel quality indication between the situation of multi-user multiple input multiple output transmission and the situation of single user multiple input multiple output transmission; adding the multi-user channel quality indication error into the downlink channel feedback information which includes a pre-coding matrix indication and a channel quality indication, and feeding the same back to a base station for scheduling. Therefore, the bit error rate of demodulation in the MIMO system can be reduced and the system performance can be improved.