Precoding Matrix Design for Macro Pico Interference Suppression
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Solution Overview
Problem
In wireless communication systems, full-duplex operations in macro and pico base stations lead to mutual interference (PT2M and MT2P) due to intra-frequency concurrent transmission and reception, which cannot be effectively mitigated by existing methods despite attempts to reduce path loss and electromagnetic interference.
Innovation Solution
A wireless communication method and apparatus that utilize channel matrices to obtain precoding matrices based on null space vectors, effectively suppressing interference by precoding transmit signals and using beamforming matrices to receive signals, thereby reducing the impact of PT2M and MT2P interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If full-duplex communication is used in macro and pico base stations, then system capacity is improved, but mutual interference (PT2M and MT2P) worsens
Solution Approach 1:
The patent changes the spatial parameters of signal transmission by using precoding matrices to adjust the direction and distribution of transmitted signals. By modifying the spatial parameters through precoding, the system maintains full-duplex operation while reducing interference through optimized signal directionality.
Solution Approach 2:
The patent introduces spatial dimensionality to the communication system by using multiple antennas and precoding matrices. This transforms the problem from a single-dimensional interference issue to a multi-dimensional spatial problem, where interference can be managed through spatial separation and beamforming techniques.
2Object-affected harmful factors
If path loss is reduced by selecting pico base station site, adjusting beam direction, or shielding direct path, then PT2M and MT2P interference is reduced, but uplink signal reception quality worsens
Solution Approach 1:
The patent applies local quality by using different precoding matrices for different spatial directions and users. Each user receives customized precoding treatment based on their specific channel conditions and spatial location, allowing interference reduction in base station-to-base station links while maintaining or improving uplink reception quality for each individual user.
Solution Approach 2:
The patent segments the communication signals into different spatial streams using precoding matrices. By dividing the transmitted signal into multiple spatially separated streams, the system can reduce interference in certain directions while maintaining signal quality in other directions, thus resolving the contradiction between interference reduction and reception quality.
3Object-affected harmful factors
If precoding matrices are designed to suppress interference, then PT2M and MT2P interference is reduced, but downlink transmission performance may be compromised
Solution Approach 1:
The patent applies partial action by designing precoding matrices that provide partial interference suppression rather than complete elimination. The precoding is optimized to reduce interference to acceptable levels while maintaining sufficient downlink transmission performance, recognizing that complete interference suppression would excessively degrade the downlink performance.
Data Source
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AI summary
Embodiments of the present invention provide a wireless communication method, an apparatus, and a base station, relate to the field of communications technologies, and can suppress impact of PT2M interference on receiving an uplink signal from UE by a macro base station and impact of MT2P interference on receiving an uplink signal from UE by a pico base station. The method includes: obtaining a first channel matrix that is from a first base station to a second base station; obtaining a second channel matrix that is from the first base station to user equipment served by the first base station; obtaining, based on the first channel matrix, a first precoding matrix, where the first precoding matrix is constituted by a null space vector of the first channel matrix; obtaining a first equivalent channel matrix that is from the first base station to the user equipment served by the first base station, where the first equivalent channel matrix is a product of the second channel matrix and the first precoding matrix; and selecting, based on the first equivalent channel matrix, a second precoding matrix for a transmit signal, performing precoding on the transmit signal according to the second precoding matrix, and sending a precoded transmit signal. The embodiments of the present invention are used for wireless communication.