Precoding Matrix for Interference Alignment in Multi-Cell Systems
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Solution Overview
Problem
Communication systems face challenges in controlling inter-cell and intra-cell interference, which affects data rates and radio resource utilization in multi-user interference channel environments, particularly for terminal devices located at cell edges.
Innovation Solution
A precoding method and communication apparatus that determine the location of terminal devices within a cell system, using channel information and signal strength, to generate zero-forcing and interference alignment precoding vectors, which are used to create a precoding matrix that reduces intra-cell interference and aligns inter-cell interference in separate signal spaces, thereby enhancing throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If terminal devices at cell edges receive signals from multiple base stations, then system capacity and resource utilization improve, but inter-cell interference increases and reduces data rates
Solution Approach 1:
The patent segments interference management by categorizing terminal devices into cell-edge devices (requiring interference alignment) and non cell-edge devices (using conventional precoding). This segmentation allows tailored interference handling strategies for different device types, improving overall system capacity while managing inter-cell interference effectively.
Solution Approach 2:
The patent introduces an interference alignment precoding vector as an intermediary mechanism that aligns inter-cell interference signals into a specific signal space separate from the desired signal space. This intermediary approach enables terminal devices to distinguish and separate desired signals from interference, thereby improving data rates despite the presence of inter-cell interference.
2Object-affected harmful factors
If interference alignment precoding is applied to all terminal devices, then inter-cell interference is reduced, but intra-cell interference control and data rate performance deteriorate
Solution Approach 1:
The patent applies local quality by using different precoding strategies for different terminal device locations. Cell-edge terminal devices receive interference alignment precoding to handle dominant inter-cell interference, while non cell-edge terminal devices receive conventional precoding optimized for intra-cell interference control. This localized approach ensures each device type receives the most appropriate interference management technique.
Solution Approach 2:
The patent implements partial action by applying interference alignment precoding only to cell-edge terminal devices where inter-cell interference is most severe, rather than to all terminal devices. This selective application avoids the performance degradation that would occur if interference alignment were applied universally, while still achieving significant interference reduction where needed.
3Device complexity
If conventional precoding is used without location-based differentiation, then system complexity remains low, but interference control performance and resource utilization are suboptimal
Solution Approach 1:
The patent introduces dynamics by making the precoding strategy adaptive to terminal device location. The base station determines whether each terminal device is a cell-edge device or not, and dynamically selects the appropriate precoding method (interference alignment or conventional precoding). This dynamic adaptation improves resource utilization and interference control performance without requiring overly complex fixed architecture.
Data Source
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AI summary
Provided are a communication apparatus that may generate a precoding matrix including precoding vectors to cancel or align interference existing in a plurality of terminal devices based on location of the terminal devices, and a terminal device that may estimate a channel formed between the terminal device and the communication apparatus to cancel or align interference signals.