Codebook Generation for Multi-Antenna Feedback Overhead
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face challenges in reducing feedback overhead while maintaining precision in multi-antenna array environments, particularly in CoMP (Coordinate Multiple Points) transmissions, where phase offsets between pre-coding matrices are crucial for coherent signal combination but increase feedback complexity.
Innovation Solution
A method is introduced to generate a codebook with phase offsets by assigning phase offsets to pre-coding matrices in a basic codebook, allowing for simultaneous feedback of phase offsets and pre-coding matrix indexes without increasing the codebook size, using a combination of basic and modified codebooks with phase offsets across different antenna arrays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If phase offsets are fed back for multiple antenna arrays to enable coherent signal combination, then signal combination precision is improved, but feedback overhead increases
Solution Approach 1:
The patent combines the pre-coding matrix index feedback and phase offset feedback into a unified codebook structure. The codebook contains multiple pre-coding matrices where each matrix inherently includes phase offset information, allowing simultaneous feedback of both parameters through a single codebook index rather than separate feedback channels.
Solution Approach 2:
The patent pre-generates a codebook with multiple pre-coding matrices that have different phase offset configurations before transmission. This allows the terminal to directly select and feedback the most appropriate pre-coding matrix based on channel conditions, eliminating the need for separate phase offset calculation and feedback procedures.
2Productivity
If a larger codebook is used to provide more pre-coding matrix options for better channel adaptation, then downlink throughput is improved, but feedback overhead increases
Solution Approach 1:
The patent segments the codebook into multiple groups or sub-codebooks, each containing pre-coding matrices suitable for different channel conditions. The terminal can first select a group based on coarse channel characteristics, then select a specific matrix within the group, reducing the total feedback bits compared to selecting from a single large codebook.
Solution Approach 2:
The patent introduces an additional dimension to the codebook structure by organizing pre-coding matrices in a hierarchical manner with multiple selection levels. This dimensional organization allows the system to achieve fine-grained channel adaptation without linearly increasing the feedback overhead, as the feedback is structured across multiple dimensions rather than a single large index.
Data Source
AI summary
The present disclosure provides a method of generating codebook in a wireless communication system with multiple antenna arrays, as well as a wireless communication system, base station and terminal using the codebook for communication. The method comprises steps of: providing a basic codebook which contains multiple pre-coding matrices; and assigning phase offsets to certain pre-coding matrices in the basic codebook to form a codebook with phase offset. The feedback overhead from a client to a base station side is reduced and a good precision of feedback for multi-antenna array is kept by applying the method of generating codebook and using the generated codebook in the wireless communication system, base station and terminal.