Inter-Cell Interference Mitigation via Dynamic Frequency Subband Allocation
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Solution Overview
Problem
Current wireless communication systems face inefficiencies in reducing inter-cell interference, particularly in frequency reuse schemes where each cell uses only a fraction of the available frequency band, leading to suboptimal resource utilization.
Innovation Solution
The system partitions the frequency band into non-overlapping subbands and allocates these subbands differently to inner and outer regions within cells, allowing adjacent outer regions in neighboring cells to use distinct frequency subbands during specific time intervals to mitigate inter-cell interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a frequency reuse scheme with a small frequency use factor (e.g., 1/7) is employed to reduce inter-cell interference, then inter-cell interference is reduced, but system resource utilization efficiency deteriorates
Solution Approach 1:
The system segments the frequency band into multiple non-overlapping subbands and further segments cells into inner and outer regions. Different frequency subbands are allocated to different outer regions of neighboring cells, while inner regions can use the entire frequency band. This segmentation allows frequency resources to be differentiated by space and function, reducing inter-cell interference for outer region users while improving overall system resource utilization efficiency.
2Object-affected harmful factors
If frequency subbands are allocated to outer regions of cells, then inter-cell interference for outer region users is reduced, but frequency resource utilization for inner region users deteriorates
Solution Approach 1:
The system applies local quality by allocating different frequency subbands specifically to outer regions of cells where inter-cell interference is most problematic, while inner region users can utilize the entire frequency band without restriction. This localized frequency allocation strategy针对性地 solves the interference problem for outer region users without unnecessarily limiting frequency resources for inner region users, thereby optimizing overall system performance.
3Productivity
If the entire frequency band is used for data transmission, then system capacity is maximized, but inter-cell interference increases significantly
Solution Approach 1:
The system implements dynamic frequency allocation where the frequency resources available to users depend on their location (inner or outer region) and the current time interval. Outer region users are dynamically assigned specific frequency subbands to avoid interference, while inner region users can access the full frequency band. This dynamic approach allows the system to adapt frequency resource allocation to actual spatial and temporal conditions, maximizing system capacity while controlling inter-cell interference.
Data Source
AI summary
Techniques to mitigate inter-cell interference using joint time and frequency division are described. A frequency band is divided into multiple non-overlapping frequency subbands. The transmission timeline is divided into Tin and Tout time intervals. Data is exchanged with users in at least one inner region of a cell on the entire frequency band in the Tin time intervals. Data is exchanged with users in multiple outer regions of the cell on the multiple frequency subbands in the Tout time intervals. The frequency band may be partitioned into three frequency subbands. Data may then be exchanged with users in first, second and third outer regions on first, second and third frequency subbands, respectively. The regions in which the users are located may be determined based on pilot and/or other measurements.