Precoding Matrix Codebook Selection for Massive MIMO Feedback

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Solution Overview

Problem

Conventional Massive MIMO communication systems face channel mismatch issues due to inadequate channel state feedback, leading to low precoding performance, especially with increasing numbers of antennas.

Innovation Solution

A method for determining channel state feedback information using a precoding codebook matrix model W=[v0v2α1⁢v1α2⁢v3β⁣·v0-β⁣·v2β⁣·α1⁢v1-β⁣·α2⁢v3], where v0, v2, v1, and v3 are vectors and α1, α2, β are phase factors, to form a precoding matrix that improves communication quality and precoding performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional channel transmission methods are used with increasing numbers of antennas, then the system can support more antennas, but channel mismatch occurs and precoding performance deteriorates

Engineering Contradiction:

Improvenumber of antennasVSAvoidprecoding performance

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent changes the parameter structure of the precoding matrix by introducing a codebook index-based selection mechanism. Instead of using fixed conventional transmission methods, the system selects precoding matrices from a codebook based on channel state feedback, adapting the precoding parameters to match the actual channel conditions. This resolves the channel mismatch problem that occurs when simply increasing the number of antennas without adapting the transmission parameters.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If detailed channel state feedback is provided to improve precoding accuracy, then precoding performance improves, but the amount of feedback information increases

Engineering Contradiction:

Improveprecoding performanceVSAvoidfeedback information overhead

Core Design Contradiction:

ReliabilityVSLoss of information

Solution Approach 1:

The patent extracts only the essential channel state information needed for precoding by using a codebook index instead of feeding back the complete channel matrix. The terminal selects the most suitable precoding matrix from the codebook and feeds back only its index, which significantly reduces feedback overhead while still enabling the base station to apply accurate precoding based on the selected matrix.

Inventive Principle:

Principle #2Taking out (Extraction)

3Device complexity

If a simple precoding matrix structure is used to reduce complexity, then device complexity decreases, but channel matching accuracy and precoding performance worsen

Engineering Contradiction:

Improveprecoding matrix complexityVSAvoidchannel matching accuracy

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent prepares multiple precoding matrices in advance within a codebook, each optimized for different channel conditions. The terminal then selects the most appropriate pre-prepared matrix based on current channel state, avoiding the need for complex real-time matrix calculations while maintaining high channel matching accuracy. This preliminary preparation resolves the contradiction between simplicity and accuracy.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS10187129B2Information feedback method, terminal, base station, communication system and storage medium

Publication Date: 2019.01.22 ZTE CORP

AI summary

Disclosed are a channel state feedback information determination method, a terminal, a base station and a communication system. The method includes that: a channel state is measured to form a measurement result; when a Rank Indicator (RI) is 2, a precoding matrix is formed according to the measurement result and a precoding codebook matrix model W; and channel state feedback information is formed according to the precoding matrix. The disclosure further discloses a computer storage medium.