Virtual Cell ID Scrambling for ePDCCH Interference Mitigation
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Solution Overview
Problem
Wireless communication networks face interference issues due to the increasing demand for mobile broadband access, leading to performance degradation in both downlink and uplink transmissions, particularly in environments with multiple base stations and user equipment (UEs).
Innovation Solution
The method involves configuring virtual cell identifiers for user equipment (UEs) to determine and scramble enhanced physical downlink control channels (ePDCCH) based on virtual cell IDs, allowing for improved interference mitigation and decoding of control channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If virtual cell identifiers are used for ePDCCH scrambling, then interference mitigation is improved and control channel capacity increases, but device complexity increases due to additional configuration and determination steps
Solution Approach 1:
The patent changes the parameter used for ePDCCH scrambling from physical cell ID to virtual cell ID. This parameter change enables frequency-domain interference coordination by allowing different virtual cell IDs to be assigned to different cells, thereby differentiating their ePDCCH scrambling sequences and reducing inter-cell interference.
Solution Approach 2:
The virtual cell ID acts as an intermediary between the physical cell ID and the ePDCCH scrambling process. Instead of directly using physical cell IDs for scrambling, the system introduces virtual cell IDs as a intermediate layer that provides additional degrees of freedom for interference management while maintaining the existing scrambling mechanism.
2Productivity
If virtual cell IDs are configured for multiple UEs, then spatial reuse of control channel resources is improved, but measurement precision requirements increase for distinguishing different virtual cell IDs
Solution Approach 1:
The patent segments the control channel resources by assigning different virtual cell IDs to different UEs or UE groups. This segmentation allows multiple UEs to simultaneously use the same physical resources (frequency and time) for ePDCCH transmission while being distinguishable through their unique virtual cell IDs, thereby improving spatial reuse efficiency.
Solution Approach 2:
The patent applies local quality by assigning specific virtual cell ID characteristics to specific UEs or regions. Each UE receives a virtual cell ID configured according to its local interference environment and service requirements, allowing optimized interference mitigation and resource allocation for each local context.
Data Source
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AI summary
A method of wireless communication includes configuring a virtual cell identifier (ID) for a user equipment (UE). The method determines a first candidate for an enhanced physical downlink control channel (ePDCCH) for the UE. The method also determines a first virtual cell ID for the first candidate. Furthermore, the method scrambles the ePDCCH based on the first virtual cell ID and transmits, to the UE, the scrambled ePDCCH using the first candidate.