Precoding Matrix Index Feedback for MIMO Interference Mitigation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In multiple-input and multiple-output (MIMO) mobile communication systems, the presence of multiple interference base stations complicates channel status estimation and precoding, leading to performance deterioration due to increased channel and interference information complexity.
Innovation Solution
A terminal estimates the status of both serving and interference channels, selects an index for a precoding matrix based on these channels, and transmits it to the base station, which uses this index to precode data, employing autocorrelation matrix generation, singular value decomposition, and null space vector selection to minimize interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a terminal transmits separate interference indices for each interference base station, then interference mitigation performance is improved, but the amount of channel status and interference information increases, deteriorating terminal and base station performance
Solution Approach 1:
The patent combines multiple interference indices from different interference base stations into a single common interference index. The terminal estimates interference channels from multiple interference base stations, processes their autocorrelation matrices, and selects a common precoding matrix index that represents the combined interference state. This single index is then fed back to both the serving base station and interference base stations, reducing information complexity while maintaining interference mitigation capability.
2Device complexity
If a terminal selects precoding matrix index based only on serving channel, then device complexity is reduced, but interference from multiple base stations cannot be effectively minimized
Solution Approach 1:
The patent introduces an interference channel estimator and autocorrelation matrix generator as intermediary components between the serving channel and the precoding matrix selection. These intermediaries process the interference channel information from multiple base stations and transform it into a form that can be integrated with serving channel information, enabling joint optimization without excessive complexity.
3Object-affected harmful factors
If each interference base station accurately estimates its own channel status to minimize interference, then interference signal effect is reduced, but the system requires increased channel status information at each base station
Solution Approach 1:
The patent creates a universal common interference index that serves multiple interference base stations simultaneously. Instead of each base station requiring its own dedicated channel status information, a single precoding matrix index is designed that can be applied across multiple interference sources, reducing the quantity of information needed while maintaining the ability to mitigate interference from each base station.
Data Source
AI summary
A communication system to feed back an index of a precoding matrix is provided. A terminal may feed back an index of an optimal precoding matrix based on estimated channel status. A base station may transmit data to the terminal based on the index of the precoding matrix received from the terminal.