Multi-Antenna Channel Feedback Using Linear Transformation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In multi-antenna systems with 32 or more ports, existing channel feedback methods face increased complexity, large feedback overhead, and poor channel quantization, limiting performance gains due to numerous antenna topologies and high vector sets.
Innovation Solution
A method involving a terminal that receives channel state information-reference signals, performs linear transformation using a transformation function to reduce dimensionality, and selects and feeds back quantized precoding matrix indicators, reducing feedback overhead and improving channel correlativity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If DFT vector-based codebook is used for 32 or more antenna ports, then channel information can be fed back, but feedback overhead increases significantly
Solution Approach 1:
The patent segments the M-dimensional channel information into multiple groups, each processed independently through linear transformation and quantization. Instead of feeding back all M-dimensional information directly, the system divides it into manageable segments that can be quantized using smaller codebooks, thereby reducing overall feedback overhead while preserving essential channel characteristics.
Solution Approach 2:
The patent extracts the most significant channel information through linear transformation that projects M-dimensional channel state onto a reduced-dimensional subspace. By taking out only the dominant components of channel information that contribute most to transmission performance, the system reduces feedback quantity while maintaining effective precoding capability.
2Measurement precision
If codebook is designed for each antenna topology, then channel quantization accuracy improves, but device complexity increases
Solution Approach 1:
The patent creates a universal linear transformation framework that works across different antenna topologies without requiring separate codebook designs. The transformation function Fk and grouping strategy can be applied generically to various antenna configurations, making the system multi-functional and topology-agnostic while maintaining quantization accuracy through adaptive parameter selection.
Solution Approach 2:
Instead of designing different codebooks for different topologies, the patent changes parameters such as the transformation matrix Fk and grouping configuration to adapt to different antenna setups. This parameter-based adaptation allows the same fundamental codebook structure to serve multiple topology types, reducing complexity while preserving accuracy.
3Quantity of substance
If dimensionality reduction is performed on M-dimensional channel information, then feedback overhead decreases, but channel description accuracy may deteriorate
Solution Approach 1:
The patent performs preliminary linear transformation on the M-dimensional channel information before quantization and feedback. This preliminary action of projecting channel state onto a reduced-dimensional subspace using transformation function Fk prepares the data in advance for efficient quantization, ensuring that the most significant channel characteristics are preserved in the reduced representation, thus maintaining accuracy while reducing dimensionality.
Data Source
AI summary
Provided are a method for channel information feedback in a multi-antenna system, and a terminal. The method comprises: a terminal receives CSI-RSs of M ports sent by a base station, and performs estimation according to the CSI-RSs to obtain M-dimensional downlink channel information; the terminal uses a transformation function Fk to perform a linear transformation on the M-dimensional downlink channel information, and obtains Nk-dimensional kth type channels, wherein k is greater than or equal to 1 and less than or equal to K, M≥Nk, and K≥1; the terminal uses a preset Nk-dimensional codebook to respectively perform channel information quantisation on the kth type channels, and determines a corresponding precoding matrix and precoding matrix indicator information (PMIk); the terminal selects S type channels from within K type channels, and feeds index numbers of the selected channels and corresponding PMI back to the base station.