TDD Interference Identification via Signal Correlation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In mobile networks using time division duplex (TDD) configurations, interference issues arise due to neighboring cells having different uplink and downlink configurations, leading to eNB-to-eNB and UE-to-UE inter-cell interference, which degrades system performance, especially near cell edges and in scenarios with varying traffic patterns.
Innovation Solution
The implementation of a method at the evolved Node B (eNB) to identify potential eNB-to-eNB and UE-to-UE interference by correlating received signals with locally generated cell-specific reference signals and determining interference based on thresholds, along with interference mitigation strategies such as power reduction and frequency reuse plans, to address the interference effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If TDD systems use different uplink and downlink configurations in neighboring cells to adapt to varying traffic patterns, then adaptability is improved, but interference increases due to eNB-to-eNB and UE-to-UE inter-cell interference
Solution Approach 1:
The system dynamically changes TDD configuration parameters (uplink-downlink subframe assignments) to adapt to varying traffic patterns. Each cell can independently adjust its configuration based on local traffic conditions, achieving adaptability while the interference identification and mitigation mechanisms manage the resulting interference
Solution Approach 2:
The system implements feedback mechanisms where eNBs identify interference types by correlating received signals with reference signals, then use this information to adjust power levels and configurations. The interference identification results feed back into the configuration decision process, enabling adaptive interference mitigation
2Ease of operation
If TDD systems allow independent configuration of uplink and downlink subframes to improve flexibility, then ease of operation is improved, but system reliability deteriorates due to interference degradation near cell edges
Solution Approach 1:
The system allows flexible configuration of TDD parameters (uplink-downlink assignments) for ease of operation, while simultaneously using interference identification and power adjustment mechanisms to maintain reliability. The configuration flexibility is managed through dynamic parameter changes based on interference conditions
Solution Approach 2:
The system applies different quality levels of interference mitigation to different spatial locations. Cell edge users experience enhanced protection through interference identification and power reduction mechanisms, while cell center users benefit from full configuration flexibility. This local differentiation maintains both flexibility and reliability
3Object-affected harmful factors
If neighboring cells use synchronized TDD configurations to reduce interference, then interference is reduced, but adaptability to varying traffic patterns is lost
Solution Approach 1:
The system transitions from static synchronized configurations to dynamic independent configurations. Each cell can dynamically adjust its TDD configuration based on local traffic patterns, while the interference identification and mitigation mechanisms dynamically adjust to manage the resulting interference, achieving both adaptability and interference control
Solution Approach 2:
Each cell independently identifies and manages its own interference conditions through signal correlation and power adjustment. The system enables cells to self-adapt to local traffic patterns and self-mitigate interference without requiring centralized coordination, achieving adaptability while maintaining interference control
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly reduces interference, enhancing system performance by allowing dynamic and flexible reconfiguration of uplink and downlink allocations, improving data throughput, and adapting to changing traffic conditions without requiring synchronized TDD configurations among neighboring cells.
Implementation Method 1
correlating a received signal with a locally generated cell specific reference signal according to an identifier for the neighbor cell eNB
Implementation Method 2
calculating a first negative acknowledgment (NAK) rate base on a percentage of NAKs received from a user equipment in a first set of subframes; calculating a second NAK rate base on a percentage of NAKs received from the user equipment in a second set of subframes
Data Source
AI summary
Methods and apparatus at an evolved Node B (eNB) and user equipment (UE) in cells operating in time division duplex with a first configuration and having a neighbor cell eNB operating in time division duplex with a second configuration, the methods and apparatus: identifying potential eNB-to-eNB; UE-to-UE; eNB-to-UE; and UE-to-eNB interference. Further methods and apparatus to report interference including enumerated interference types to neighbor cell eNBs. Further, methods and apparatus for interference mitigation.