Channel State Feedback Codebook for Near-Field Subarray Precoding
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Solution Overview
Problem
Existing MIMO wireless communication systems face significant gain loss in near-field regions due to the violation of plane wave approximation, and existing near-field precoding schemes are computationally complex and incompatible with standard protocols.
Innovation Solution
A subarray precoding method is employed, where a MIMO array is divided into subarrays, and channel state information is fed back using a codeword constructed from a basis vector model, reducing computational complexity and maintaining compatibility with existing protocols.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional far-field precoding is used in near-field region, then protocol compatibility is maintained, but significant gain loss occurs
Solution Approach 1:
The patent divides the large-scale antenna array into multiple subarrays, where each subarray independently performs precoding operations. This segmentation allows the system to adapt to near-field conditions while maintaining compatibility with existing protocols that operate at the array level, thereby resolving the contradiction between protocol compatibility and performance optimization.
2Loss of energy
If existing near-field precoding schemes are implemented, then gain loss is reduced, but computational complexity increases significantly
Solution Approach 1:
By dividing the large array into smaller subarrays, the computational complexity of near-field precoding is reduced from O(N^2) for the entire array to O(k*N^2/d) for k subarrays of size d, making near-field precoding practically implementable while still reducing gain loss.
Solution Approach 2:
The patent changes the precoding parameter granularity from array-level to subarray-level, allowing independent optimization of each subarray's precoding parameters. This parameter change enables the system to achieve near-field performance benefits without the prohibitive computational complexity of full-array near-field precoding.
3Quantity of substance
If array aperture is increased to obtain more spectrum resources, then bandwidth increases, but near-field region expands causing far-field approximation to fail
Solution Approach 1:
The patent segments the large aperture array into multiple subarrays, each with smaller effective aperture. This segmentation allows the system to utilize the large total aperture for spectrum resources while each subarray operates within the far-field approximation validity range, thereby resolving the contradiction between spectrum resource acquisition and approximation validity.
Data Source
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AI summary
Provided are a channel information feedback method, an electronic device, and a storage medium. The method includes determining a measurement result of channel state information according to a measured reference signal; determining a codebook, where the codebook includes at least one codeword; determining a codeword W within the codebook according to the measurement result; and feeding back indication information of the codeword W. The codeword W is a matrix that has N rows and r columns and includes r column vectors V1, V2, ..., Vr, where N > 1, and r ≥ 1. The i-th column vector Vi of the codeword W is constructed according to the following basis vector model u: u=α1ν1α2ν2⋮αKνK, where the basis vector model u includes K sub-vectors, the length of the k-th sub-vector vk is Nk, and αk is a sub-vector coefficient. At least one subset FS1 in a set FS including sub-vectors and sub-vector coefficients in the basis vector is determined according to at least one subset FS2 in the set FS. Channel information feedback for near-field communication is implemented through subarray precoding, thereby enhancing the beamforming gain.