Massive MIMO CSI Feedback Using Polarized Precoding Codebooks
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Solution Overview
Problem
The complexity of channel measurement in Massive MIMO systems using polarization direction-based diversity transmission schemes is high, leading to inefficiencies in channel measurement and reduced data transmission reliability.
Innovation Solution
A method involving the feedback of multiple precoding vectors based on different polarization directions, using a restricted candidate element set in the codebook to reduce channel measurement complexity and enhance data transmission reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the terminal device traverses precoding matrices corresponding to multiple PMIs in the same rank to perform channel measurement, then the channel measurement can be performed, but the complexity of channel measurement becomes relatively high
Solution Approach 1:
The codebook is segmented into multiple codebook subsets, each corresponding to different transmission schemes (e.g., polarization direction-based diversity transmission scheme, spatial multiplexing scheme). The terminal device selects and uses only the codebook subset corresponding to the current transmission scheme, rather than traversing all codebooks. This segmentation reduces the number of precoding matrices that need to be measured while ensuring accurate channel measurement for the specific transmission scheme being used.
2Reliability
If a single precoding vector is fed back in the prior art, then the feedback process is simple, but it does not meet the requirement of diversity transmission scheme and cannot provide multiple precoding vectors for data transmission
Solution Approach 1:
The codebook configuration is made dynamic and adaptable to different transmission schemes. The network device configures different codebook subsets for different transmission schemes, and the terminal device dynamically selects the appropriate codebook subset based on the detected transmission scheme. This dynamic adaptation enables the system to provide multiple precoding vectors when diversity transmission is required, while maintaining simple feedback processes for other schemes.
3Loss of information
If the terminal device performs channel measurement for all precoding matrices in the codebook, then complete channel state information can be obtained, but the measurement efficiency is reduced
Solution Approach 1:
The codebook is pre-configured and divided into multiple subsets according to different transmission schemes before actual channel measurement. The terminal device performs preliminary detection of the transmission scheme and selects the corresponding codebook subset in advance, avoiding the need to measure all precoding matrices in the entire codebook. This preliminary action ensures that complete channel state information is obtained for the relevant transmission scheme while significantly improving measurement efficiency.
Data Source
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AI summary
This application provides a communication method, a communications apparatus, and a system. The method includes: receiving, by a terminal device, a first group of precoded reference signals and a second group of precoded reference signals; feeding back first indication information based on a CSI feedback-based transmission scheme, where the first indication information is used to determine a plurality of precoding vectors, at least one of the plurality of precoding vectors is determined by using the first group of precoded reference signals, and at least one of the plurality of precoding vectors is determined by using the second group of precoded reference signals. The first indication information is used to indicate a first element in a codebook, the first element is used to determine at least one port, each port indicates a precoding vector corresponding to one precoded reference signal, at least one candidate element including the first element is predefined in a codebook corresponding to a same rank, and ports indicated by any two candidate elements are at least partially different.