CSI Feedback Optimization Using Precoding Matrix Parameter Extraction
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Solution Overview
Problem
High precision codebook-based precoding matrices in MIMO systems require significant resource overhead for CSI feedback, particularly due to the large quantity of bits needed to convey the PMI2, which affects communication efficiency.
Innovation Solution
The proposed method reduces resource overhead by allowing the terminal device to indicate only the necessary parameters of the precoding matrix W2 using RI and indication information, enabling the network device to derive PMI2, thereby minimizing the bits required for PMI2 feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high precision codebook-based precoding matrix is used, then signal transmission quality and system channel capacity are improved, but resource overhead for CSI feedback increases significantly
Solution Approach 1:
The patent extracts only the essential parameters needed to reconstruct the precoding matrix W2. Instead of feeding back all elements of W2, the terminal device feeds back PMI2 that indicates only the parameters of non-zero elements, along with indication information that specifies the positions of zero elements. This extraction approach reduces feedback overhead while maintaining the ability to reconstruct the full precoding matrix at the network device.
Solution Approach 2:
The patent changes the parameter representation from indicating all elements of W2 to indicating only non-zero elements. The PMI2 parameter is redefined to indicate parameters of specific elements rather than all elements, and indication information is added to specify which elements are zero. This parameter transformation significantly reduces the number of bits required for feedback while preserving the essential information needed for precoding matrix reconstruction.
2Loss of information
If PMI2 indicates all elements of W2, then complete precoding matrix information is obtained, but quantity of bits for feedback increases
Solution Approach 1:
The patent extracts only the necessary information for reconstructing W2 by identifying and indicating only the non-zero elements. The PMI2 is designed to indicate parameters of non-zero elements, and indication information specifies the positions of zero elements. This selective extraction maintains complete precoding matrix information while minimizing feedback bit requirements.
Solution Approach 2:
Instead of indicating all elements of W2, the patent uses partial action by indicating only the non-zero elements. The indication information complements this by specifying which elements are zero, so the combination provides complete information. This partial indication approach reduces feedback overhead while maintaining information completeness through the synergistic use of PMI2 and indication information.
Data Source
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AI summary
A channel state information sending method, a channel state information receiving method, and a device are disclosed, to reduce resource overheads required when a terminal device feeds back CSI to a network device in a scenario of a high precision codebook-based precoding matrix. The method includes: determining, by a terminal device, a precoding matrix W; sending, by the terminal device, a signal including CSI to a network device; obtaining, by the network device, an RI and indication information based on the signal including the CSI; obtaining, by the network device, a PMI2 based on the RI and the indication information; and determining, by the network device, the precoding matrix W based on the rank indicator RI and the second precoding matrix indicator PMI2.