(20,10,6) Codebook for WCDMA MIMO CQI Reliability
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Solution Overview
Problem
Existing WCDMA systems face challenges in reliably transmitting Multiple-Input-Multiple-Output (MIMO) channel quality indicators (CQI) and antenna weight indicators (AWI) due to insufficient channel coding protection, resulting in a weaker minimum Hamming distance of 4, which requires more power to transmit detailed MIMO CQI reports effectively.
Innovation Solution
A (20,10,6) codebook is implemented, providing a generator matrix that increases the minimum Hamming distance to 6, allowing for better protection and efficient transmission of CQI and AWI information by utilizing a quadratic residue generator matrix of the (24,12,8) Golay code, which is then shortened and punctured to achieve a (20,10,6) code with improved error correction capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a (20,10,4) code is used for MIMO CQI feedback, then the feedback message can be transmitted, but the minimum Hamming distance is only 4 which provides insufficient channel coding protection and requires more transmission power
Solution Approach 1:
The patent changes the fundamental parameter of the channel code from a (20,10,4) code with minimum Hamming distance 4 to a (20,10,6) code with minimum Hamming distance 6. This parameter change in the code's error correction capability directly improves reliability while reducing the required transmission power for the same error rate performance.
2Productivity
If more detailed CQI reporting is implemented for MIMO transmission, then spectral efficiency and system throughput are increased, but the feedback message length increases requiring more channel coding protection
Solution Approach 1:
The patent applies preliminary action by pre-defining a optimized (20,10,6) codebook with superior error correction properties before the actual CQI feedback transmission. This pre-prepared code structure ensures that when detailed MIMO CQI reports need to be transmitted, the system already has the appropriate coding protection in place, eliminating the need for ad-hoc code selection and ensuring reliable transmission from the outset.
Data Source
AI summary
A block coding method and system for improving the reliability of Channel Quality Indicators (CQI) and Antenna Weight Indicators (AWI) reporting, A user terminal first generates 8-bit CQI and 2-bit AWI. A codeword generator produces a codeword responsive to these 10 CQI/AWI bits using a codebook or a generator matrix of a (20,10,6) code. The (20,10,6) code has a minimum Hamming distance of 6. The encoded codeword is transmitted to a receiver for decoding utilizing an identical (20,10,6) codebook.