UE Interference Cancellation Using Split Frequency Offset Compensation
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Solution Overview
Problem
Satellite communication systems face significant interference due to cell-specific reference signal overlap between adjacent cells, leading to deteriorated performance of user equipment (UE) and network performance.
Innovation Solution
The UE divides the frequency difference between the serving cell and the interference cell into a subcarrier offset and a residual frequency offset, and performs an interference signal removing operation, which includes a method for compensating for the subcarrier and residual frequency offset to efficiently remove interference signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the base station transmits cell-specific reference signal over the entire bandwidth, then the coverage is widened, but CRS signal interference occurs between adjacent cells
Solution Approach 1:
The patent extracts and removes the interfering CRS signal from the received signal. By detecting the interference cell's CRS and subtracting it from the total received signal, the method isolates and eliminates the harmful interference component, allowing the UE to receive signals from multiple cells simultaneously without CRS interference degradation.
2Reliability
If frequency offset difference between serving cell and interference cell is large, then the interference signal removing operation becomes more complex, but the interference removal effectiveness decreases
Solution Approach 1:
The patent segments the frequency offset difference into two components: a subcarrier offset (integer multiple of SCS) and a residual frequency offset. This segmentation allows the method to handle large frequency offset differences systematically by addressing each component separately through different compensation operations, maintaining effectiveness while managing complexity.
Solution Approach 2:
The patent implements dynamic interference removal operations that adapt to the detected frequency offset characteristics. When a CRS collision is detected, the method dynamically switches between different compensation strategies (repeated compensation when residual offset is large, single compensation when residual offset is small), optimizing the balance between complexity and effectiveness for each scenario.
3Reliability
If the UE performs repeated compensation for frequency offset difference, then the interference signal is removed more effectively, but the processing time increases
Solution Approach 1:
The patent implements dynamic compensation strategies based on the detected residual frequency offset. When the residual offset is large, repeated compensation is performed to achieve effective interference removal. When the residual offset is small, single compensation suffices. This dynamic adaptation significantly reduces processing time compared to always performing repeated compensation, while maintaining effectiveness when needed.
Data Source
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AI summary
Provided are a user equipment (UE) for removing an interference signal caused by an adjacent cell and an operating method of the UE. The operating method of the UE communicating with a base station (BS) includes calculating a frequency offset difference between a serving cell and an interference cell based on a first frequency offset for the serving cell and a second frequency offset for the interference cell, the frequency offset difference including a subcarrier offset and a residual frequency offset, the subcarrier offset being an integer multiple of a subcarrier spacing (SCS), and removing an interference signal from a reception signal received by the UE by compensating for the frequency offset difference based on the residual frequency offset.