Precoding Matrix Selection via Codebook Subset Restriction
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Solution Overview
Problem
In wireless communication systems, co-channel interference between user equipments (UEs) operating in the same resource area deteriorates channel performance, and existing methods are inefficient in reducing this interference while also minimizing feedback overhead.
Innovation Solution
The method involves determining and transmitting precoding matrix information from user equipment (UE) to a base station, including a first precoding matrix for the UE and one or more second precoding matrices for other UEs within a predetermined codebook subset, to reduce co-channel interference and feedback overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple UEs are multiplexed in the same resource area using MU-MIMO, then system capacity and data communication efficiency are improved, but co-channel interference between UEs deteriorates channel performance
Solution Approach 1:
The patent changes the parameter of precoding matrix selection by introducing codebook subset restriction. The base station configures specific UEs to select precoding matrices only from certain codebook subsets rather than the entire codebook, which modifies the signal transmission characteristics to reduce co-channel interference while maintaining system capacity
Solution Approach 2:
The base station performs preliminary configuration by informing UEs of the allowed codebook subsets before actual data transmission. This preliminary action enables UEs to pre-determine their precoding matrix options, ensuring interference mitigation is built into the transmission strategy from the outset
2Adaptability or versatility
If the entire codebook is used for precoding matrix selection, then precoding flexibility and adaptability are maximized, but feedback overhead increases
Solution Approach 1:
The patent extracts a specific subset of precoding matrices from the complete codebook that is relevant to the current transmission scenario. By configuring UEs to select only from this extracted subset rather than the entire codebook, feedback overhead is reduced while retaining the necessary precoding flexibility for effective interference management
Solution Approach 2:
Different codebook subsets are configured for different UEs based on their specific channel conditions and interference scenarios. This local quality approach allows each UE to have tailored precoding options optimized for its situation, maintaining adaptability while reducing overall feedback requirements
Data Source
AI summary
The present invention relates to a precoding matrix information transmission method and a user device, and provides a method for transmitting precoding matrix information by a particular user device among user devices that receive a signal transmitted from one base station. The method comprises the steps of: determining, from a predetermined codebook, a first precoding matrix which is a precoding matrix for the particular user device during signal reception, and determining one or more second precoding matrices for the other user devices which are to be multiplexed in a predetermined resource region with the particular user device, wherein the one or more second precoding matrices are determined within a codebook subset of the predetermined codebook linked with the first precoding matrix; and transmitting, to the base station, first precoding matrix information indicating the first precoding matrix and second precoding matrix information indicating the one or more second precoding matrices.