TD-LTE Interference Mitigation via Time Offset Synchronization
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Solution Overview
Problem
Interference between wireless communication terminals using different uplink/downlink (UL/DL) configurations in Time-Division Long-Term Evolution (TD-LTE) systems, leading to communication blockages and performance degradation, particularly when downlink sub-frames of one terminal overlap with uplink sub-frames of another.
Innovation Solution
Implementing a time offset between alternating UL/DL patterns used by base stations to minimize interference, synchronizing the patterns to avoid sub-frame overlaps and applying interference mitigation processes during special sub-frames, including signal weighting, alternative synchronization methods, and adaptive receiver settings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple TD-LTE networks use different UL/DL configurations in the same geographical area, then network versatility and adaptability are improved, but interference between terminals increases
Solution Approach 1:
The patent applies local quality by allowing different UL/DL configurations in different geographical areas or network sectors. Each base station can select configurations adapted to local traffic patterns while the time offset mechanism ensures that locally optimized configurations do not cause harmful interference to neighboring networks. This resolves the contradiction by enabling configuration diversity where needed while maintaining interference coordination.
Solution Approach 2:
The patent changes the timing parameter by introducing a time offset between the alternating UL/DL patterns of different networks. This parameter change transforms the interference problem into a solvable synchronization problem, allowing multiple networks to operate with different configurations without terminal interference, thus maintaining both versatility and reducing harmful effects.
2Productivity
If downlink sub-frames of one terminal overlap with uplink sub-frames of another terminal, then time utilization efficiency is improved, but communication reliability deteriorates due to interference
Solution Approach 1:
The patent applies preliminary action by pre-synchronizing base stations and pre-coordinating time offsets before terminals begin communication. This advance coordination ensures that downlink and uplink sub-frames from different networks do not overlap in a way that causes interference, maintaining both time utilization efficiency and communication reliability through proactive interference prevention.
3Adaptability or versatility
If base stations synchronize with different timing, then adaptability to different network requirements is improved, but interference mitigation becomes more difficult
Solution Approach 1:
The patent changes the synchronization parameter by introducing a controlled time offset between different base station networks. This parameter transformation allows base stations to maintain different timing configurations for adaptability while the defined offset relationship simplifies the synchronization complexity by providing a clear reference framework for coordination.
Data Source
AI summary
A method for communication includes communicating between one or more first base stations (28A) and first wireless communication terminals (32A) using a first alternating pattern (56) of downlink time intervals and uplink time intervals. A time offset is selected between the first alternating pattern and a second alternating pattern (60), which is used by one or more second base stations (28B) for communicating with second wireless communication terminals (32B), so as to minimize impact of interference between the first and second wireless communication terminals. The first base stations are synchronized relative to the second base stations according to the selected time offset.