Control Channel Resource Allocation for LTE-A Interference Management
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Solution Overview
Problem
In next-generation mobile communication systems like LTE-A, the control channel designed for distributed transmission faces challenges in managing inter-cell interference and fulfilling performance requirements, especially in MU-MIMO environments, leading to reduced control channel capacity and increased interference.
Innovation Solution
A method and apparatus for efficiently managing the ratio between the control channel region carrying a common reference signal (CRS) and a dedicated control channel region carrying a dedicated reference signal (DRS), allowing for increased DRS capacity without additional blind demodulation operations, by configuring the control channel structure to optimize resource allocation based on UE conditions and data channel transmission schemes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the control channel is designed based on distributed transmission to minimize inter-cell interference, then inter-cell interference is reduced, but the control channel capacity and performance are insufficient for MU-MIMO transmission
Solution Approach 1:
The control channel is segmented into two distinct types: legacy control channels (PDCCH) using common reference signals for backward compatibility, and new control channels (ePDCCH) using dedicated reference signals for enhanced MU-MIMO support. This segmentation allows each control channel type to be optimized for its specific function without compromising the other.
Solution Approach 2:
Different control channel regions are assigned different reference signal types based on local requirements. The legacy control channel region uses common reference signals for broad compatibility, while the new control channel region uses dedicated reference signals for specialized MU-MIMO performance. This local quality differentiation resolves the contradiction by providing appropriate control channel capacity where needed while maintaining low interference through distributed transmission design.
2Adaptability or versatility
If the legacy control region is reduced to assign new resources for Rel-11 UE-RS based PDCCH, then resource allocation flexibility is improved, but the control channel reception efficiency may be compromised
Solution Approach 1:
The patent establishes predetermined rules and higher-layer signaling mechanisms that inform UEs about the locations and configurations of new control channel regions before transmission occurs. This preliminary action allows UEs to efficiently search and receive new control channels without compromising reception efficiency, while the network gains flexibility in resource allocation.
Solution Approach 2:
Higher-layer signaling acts as an intermediary between the network's resource allocation decisions and the UE's reception process. The signaling provides necessary configuration information about new control channel regions, enabling flexible resource allocation while maintaining reliable reception through informed UE behavior.
3Quantity of substance
If the control channel region with dedicated reference signal is increased, then the dedicated control channel capacity is improved, but the number of blind demodulation operations increases
Solution Approach 1:
The network performs preliminary configuration of new control channel regions through higher-layer signaling, providing UEs with specific location and format information. This preliminary action eliminates the need for UEs to perform blind demodulation across the entire bandwidth, allowing increased dedicated control channel capacity without proportionally increasing blind demodulation operations.
4Stability of the object's composition
If the control channel is designed for LTE with distributed transmission, then backward compatibility is maintained, but it is difficult to fulfill performance requirements in LTE-A MU-MIMO transmission
Solution Approach 1:
The control channel structure is segmented into legacy and new regions, allowing the legacy control channel to maintain backward compatibility while the new control channel provides enhanced performance for MU-MIMO. This segmentation resolves the contradiction by enabling both compatibility and performance advancement to coexist in the same system.
Solution Approach 2:
The control channel structure achieves universality by supporting multiple functions: the legacy control channel region serves backward compatibility requirements for Rel-10 and earlier UEs, while the new control channel region serves advanced MU-MIMO transmission requirements. This multi-functionality allows the system to fulfill both compatibility and performance requirements simultaneously.
Data Source
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AI summary
Methods and apparatus for receiving a first control channel and a second control channel in a wireless communication system are provided. Control information for receiving the second control channel from a base station is received through higher layer signaling. A second control channel resource is determined from an entire control channel resource based on the control information. A first control channel resource is determined from the entire control channel resource according to the second control channel resource.