MIMO Channel Matrix Grouping for Interference Reduction

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Solution Overview

Problem

In MIMO systems, the interference among signals transmitted via multiple antennas leads to a decrease in Signal-to-Noise Ratio (SNR) due to non-orthogonal relationships between channel columns, resulting in lower signal quality.

Innovation Solution

The method involves dividing the channel matrix columns into groups and applying the Singular Value Decomposition (SVD) scheme to each group, allowing for the calculation and feedback of precoding matrices to improve signal processing and transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the SVD scheme is applied to the entire channel matrix to achieve beam forming and increase data transmission capacity, then the signal-to-noise ratio (SNR) and transmission gain are improved, but interference among signals from multiple antennas increases due to non-orthogonal channel columns

Engineering Contradiction:
Improvesignal qualityVSAvoidinterference among signals
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent divides the channel matrix columns into multiple groups and applies SVD to each group separately rather than to the entire matrix. This segmentation reduces the complexity of the SVD operation and allows for more effective interference management while maintaining beam forming capabilities, thereby improving signal quality without excessive interference.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different processing strategies to different groups of channel columns. By grouping columns with similar characteristics and applying SVD locally to each group, the system optimizes the signal processing for each spatial dimension independently, reducing overall interference while maintaining high SNR in the dominant signal directions.

Inventive Principle:
Principle #3Local quality

2Productivity

If multiple data streams are transmitted simultaneously via multiple antennas to increase data transmission speed, then the throughput is improved, but interference among the streams increases due to non-orthogonal channel relationships

Engineering Contradiction:
Improvedata transmission speedVSAvoidinterference among data streams
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent segments the channel matrix into groups of columns and applies SVD to each group separately. This allows the system to maintain multiple simultaneous data streams while managing interference by processing each spatial dimension independently, thereby preserving high throughput without excessive interference between streams.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent incorporates feedback mechanisms where the receiving end calculates precoding matrices based on channel state information and feeds this information back to the transmitting end. This feedback loop allows the system to adaptively adjust transmission parameters to minimize interference among multiple data streams while maintaining high transmission speed.

Inventive Principle:
Principle #23Feedback

3Reliability

If the channel matrix is processed using traditional SVD to achieve beam forming, then the transmission gain is improved, but the complexity of signal processing increases

Engineering Contradiction:
Improvetransmission gainVSAvoidsignal processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the channel matrix into groups and applies SVD to each group separately, which reduces the computational complexity compared to applying SVD to the entire matrix. This segmentation approach maintains transmission gain by preserving the essential spatial information while reducing the processing burden.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies SVD only to the necessary portions of the channel matrix (specifically to grouped columns) rather than to the entire matrix. This partial application of SVD achieves sufficient beam forming capability and transmission gain while significantly reducing the overall processing complexity.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS7796703B2Method of processing received signals in a multi-input multi-output (MIMO) system
Publication Date: 2010.09.14 THOMSON LICENSING SA
  • US7796703B2 patent drawing
  • US7796703B2 patent drawing
  • US7796703B2 patent drawing

AI summary

A method of processing data by using a plurality of antennas and by applying weight to each signal received via a corresponding antenna in a wireless communication system is disclosed. More specifically, the method includes estimating a channel matrix corresponding to the received signal and dividing columns of the channel matrix into at least two groups. Here, each group includes at least one column. Furthermore, the method includes applying a Singular Value Decomposition (SVD) scheme to each group.