Base Station Interference Handling via Dynamic Blank Time Slot Adjustment
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Solution Overview
Problem
In heterogeneous cellular networks, inter-cell interference is challenging to manage, especially when deploying pico-cell and femto-cell base stations within macro-cells, leading to difficulties in optimizing communication quality at cell edges due to power attenuation and interference from neighboring cells.
Innovation Solution
A method involving cooperative interference control through time division multiplexing, where base stations determine and adjust blank time slots based on terminal location information and interference metrics, using direct signaling or upper layer management devices to optimize radio resource allocation and reduce interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If base stations are deployed densely to accommodate more terminals, then system capacity increases, but inter-cell interference increases and communication quality at cell edges deteriorates
Solution Approach 1:
The frequency band is segmented into multiple sub-bands, and different sub-bands are allocated to different cells. This segmentation allows adjacent cells to use different frequency resources, thereby reducing inter-cell interference while maintaining system capacity through efficient frequency utilization.
Solution Approach 2:
Different power levels and frequency allocations are applied locally at cell edges versus cell centers. Cell-edge terminals receive enhanced power compensation and dedicated frequency resources, while cell-center terminals use standard allocations. This local quality differentiation optimizes communication quality at interference-prone cell edges without sacrificing overall system capacity.
2Object-affected harmful factors
If FFR is applied to suppress interference, then inter-cell interference is reduced, but device complexity and coordination overhead increase
Solution Approach 1:
Instead of applying full FFR coordination across all base stations and frequency bands, the invention selectively applies frequency segmentation and power compensation only to cell-edge terminals experiencing significant interference. This partial action approach maintains interference suppression benefits while reducing coordination complexity and overhead.
Solution Approach 2:
Cell-edge terminals autonomously identify their interference conditions and request appropriate power compensation and frequency allocation adjustments. The base station processes these local requests without requiring extensive inter-base-station coordination, enabling interference management through distributed terminal-initiated actions rather than centralized control.
3Reliability
If power is increased to improve cell-edge communication, then communication quality improves, but interference to other cells increases
Solution Approach 1:
Power compensation is applied locally and selectively only to transmissions intended for cell-edge terminals, rather than uniformly increasing power across all transmissions. This localized power enhancement improves cell-edge communication quality while minimizing the generation of interference to other cells, as only necessary transmissions receive power boosting.
Solution Approach 2:
The frequency band is segmented such that cell-edge transmissions use dedicated sub-bands different from those used by adjacent cells. This frequency segmentation allows power to be increased for cell-edge communications without proportionally increasing interference to other cells, since the interfered frequencies are different from those being transmitted at high power.
Data Source
AI summary
In a radio communication system where a base station provides blank time slots to avoid inter-cell interference, a decrease in throughput by an excess or shortage of blank time slots is prevented. This invention relates to a radio system that avoids interference in cooperation between base stations by providing blank time slots by a (first) base station. Other (second) base stations detect the number of served terminals affected by interference from the first base station that sets blank time slots, calculate required blank time slots so that the number of required blank time slots will increase with an increase in the number of terminals located in cell edges, and send a notification of the required blank time slots to the first base station. The first base station determines whether system throughput is anticipated to improve, based on the above notifications, and adjusts the length of blank time slots.