Inter-Cell Interference Coordination in Heterogeneous Wireless Networks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In heterogeneous wireless communication networks, high handover failure rates occur due to inter-cell signal interference between macro and small-cell base stations, leading to reduced network performance and increased signaling loads.
Innovation Solution
A method where a serving base station coordinates radio resources with neighboring base stations to avoid simultaneous use of coordinated radio resources, ensuring orthogonal usage in time, frequency, code, or space domains, thereby reducing inter-cell signal interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If small-cell base stations are introduced to improve network capacity and coverage, then system capacity and coverage are improved, but inter-cell signal interference increases leading to high handover failure rates
Solution Approach 1:
The network side performs preliminary identification of user equipment that may experience interference from small-cell base stations before handover occurs. By detecting reference signals from small cells and evaluating interference levels in advance, the system can proactively adjust handover parameters or notify the UE to adjust reception parameters, preventing handover failures before they occur.
Solution Approach 2:
The system implements a feedback mechanism where the network side receives interference information from user equipment regarding small-cell base stations. This feedback loop enables the network to continuously monitor interference conditions and dynamically adjust handover strategies, resource allocation, or small-cell transmission parameters to maintain reliable handovers while preserving network capacity benefits.
2Reliability
If frequent handover is performed to maintain connection quality in heterogeneous networks, then connection quality is maintained, but signaling load and processing complexity increase
Solution Approach 1:
The system performs preliminary interference assessment by detecting small-cell reference signals before handover is triggered. By identifying potentially interfering small cells in advance and evaluating the interference level, the system can make informed decisions about whether handover is truly necessary, avoiding unnecessary handovers that would increase signaling load while still maintaining connection quality when needed.
Solution Approach 2:
The system dynamically adjusts handover parameters such as threshold values and offset parameters based on detected small-cell interference conditions. When interference is detected, the system modifies handover parameters to be more conservative, reducing the frequency of handovers. When interference is absent, normal handover parameters apply, ensuring connection quality is maintained without excessive signaling overhead.
3Area of stationary object
If downlink power of small-cell base station is increased to improve coverage, then coverage is improved, but downlink interference on macro cell users increases
Solution Approach 1:
The system applies different power levels to different spatial locations and user groups. Small-cell base stations transmit at higher power specifically for their served users within their coverage area, while macro-cell users experience reduced interference through coordinated resource allocation. This local quality adjustment allows coverage improvement for small-cell users without proportionally increasing interference to macro-cell users.
Solution Approach 2:
The network side identifies user equipment that may be interfered with by small-cell downlink transmissions before allocating resources. By detecting potential interference scenarios in advance, the system can pre-configure resource allocation patterns, apply interference coordination techniques, or adjust small-cell power settings for specific time-frequency resources, thereby improving small-cell coverage while protecting macro-cell users from excessive interference.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The present invention relates to a method, a base station, and a radio communication system for reducing inter-cell signal interference. The method for reducing inter-cell signal interference includes: sending, by a serving base station, a user identity of a served user equipment to an neighboring second base station, coordinating a radio resource with the second base station, and obtaining a coordinated radio resource for scheduling the user equipment corresponding to the user identity, so that a base station that is neighboring to a base station using the coordinated resource to schedule the user equipment corresponding to the user identity avoids using the coordinated radio resource; and using, by the serving base station, the coordinated radio resource to schedule the user equipment corresponding to the user identity.