MIMO Transmitter Feedback Control via SVD Decomposition
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Solution Overview
Problem
Conventional MIMO systems face performance variability with the number of users and channel environments, and suffer from high feedback load in multi-user environments, limiting their capacity and efficiency.
Innovation Solution
The method determines and transmits only necessary feedback information based on the type of feedback required, optimizing system capacity while reducing feedback load by using a transmitter and receiver that selectively feed back decoding order and SINR information for successive interference cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If full channel matrix information is fed back from receiver to transmitter, then transmitter can achieve maximum MIMO performance through SVD, but the feedback amount becomes very large making it difficult to use in time-varying channels
Solution Approach 1:
The patent extracts only the essential components needed for MIMO performance - specifically singular values and selected eigenvectors - rather than feeding back the complete channel matrix. This selective extraction maintains transmitter capability while dramatically reducing feedback overhead to match time-varying channel conditions.
2Loss of information
If partial channel information is fed back to reduce feedback load, then feedback amount is reduced, but transmitter performance cannot be maximized
Solution Approach 1:
The patent transforms the channel matrix into a different parameter representation through SVD decomposition, extracting singular values and eigenvectors that capture the essential channel characteristics. This parameter transformation enables compact feedback while preserving the information needed for optimal transmitter performance.
3Reliability
If PU2RC technology is used to improve performance through multi-user diversity, then system performance increases in multi-user environments, but interference between data streams cannot be cancelled
Solution Approach 1:
The patent segments the feedback information into distinct components - singular values for channel gain information and eigenvectors for spatial direction information. This segmentation allows the system to selectively use different components for different purposes, enabling both performance optimization and interference management through successive interference cancellation.
4Object-generated harmful factors
If PARC or PSRC technologies are used to enable successive interference cancellation, then interference between data streams can be cancelled, but performance cannot be increased using multi-user diversity
Solution Approach 1:
The patent creates a universal feedback mechanism based on SVD that serves multiple functions simultaneously - providing channel state information for rate adaptation, spatial information for beamforming, and structured information for successive interference cancellation. This multi-functional approach enables both interference cancellation and multi-user diversity gains within a unified framework.
Data Source
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AI summary
Provided are a method of controlling a multi-user multiple input multiple output (MIMO) system and a transmitter/receiver used in the method. In the method, it can be determined whether feedback information is fed back according to the feedback information type rather than being indiscriminately provided to a transmitter, and then only a necessary feedback information type is transmitted, thereby increasing system capacity while reducing feedback load.