MU-MIMO User Terminal Interference Elimination
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Solution Overview
Problem
In MU-MIMO systems, when the total number of receive antennas of multiple user terminals exceeds the number of beams transmitted by a base station, channels are not orthogonalized, leading to interference among reception signals.
Innovation Solution
A user terminal configured to generate first channel estimation information, perform interference signal elimination, and use postcoding based on the second channel estimation information to detect desired signals, ensuring orthogonal transmission even when the number of receive antennas exceeds the number of beams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If block diagonalization precoding matrix is used for MU-MIMO, then interference among reception signals can be avoided when the number of receive antennas is less than or equal to the number of beams, but interference arises when the total number of receive antennas of multiple user terminals exceeds the number of beams transmitted by the base station
Solution Approach 1:
The patent divides the channel estimation process into two distinct stages: first channel estimation information is obtained using conventional methods, then second channel estimation information is obtained by applying interference signal elimination processing to the first channel estimation information. This segmentation allows the system to handle cases where the number of receive antennas exceeds the number of beams by processing different aspects of channel estimation separately, thereby resolving the contradiction between maintaining orthogonalization and supporting more user terminals.
2Productivity
If the number of user terminals is increased beyond the number of beams, then system capacity is improved, but channel orthogonalization fails and interference occurs
Solution Approach 1:
The patent introduces an intermediary processing step between initial channel estimation and final signal detection. The interference signal elimination processing acts as a mediator that takes the first channel estimation information (which may contain interference when multiple terminals are served) and transforms it into second channel estimation information with reduced interference. This intermediary process enables the system to maintain signal quality while increasing the number of served user terminals, thus resolving the contradiction between productivity and reliability.
Data Source
AI summary
User terminal 20 configured to perform MIMO transmission with radio base station 10 includes: control section 200 configured to generate first channel estimation information based on a reference signal transmitted by radio base station 10, and perform an operation for elimination of an interference signal on the first channel estimation information to generate second channel estimation information; and postcoder 208 configured to perform postcoding, based on the second channel estimation information, on a data signal to be transmitted by the radio base station 10, so as to detect a desired signal.