R-PDCCH Resource Mapping for Reliable Relay Control Transmission

The patent segments the R-PDCCH resource allocation process into distinct stages: CCE interleaving (dividing control channel elements into groups), VRB mapping (mapping interleaved CCEs to virtual resource blocks), and PRB allocation (assigning VRBs to physical resource blocks). This segmentation allows each stage to be optimized independently, improving transmission reliability through frequency diversity while maintaining manageable complexity through standardized procedures at each stage.

The patent introduces Virtual Resource Blocks (VRBs) as an intermediary layer between CCEs and physical PRBs. The VRB acts as a buffer that decouples the logical channel structure from physical resource allocation, enabling flexible mapping strategies (localized or distributed) without changing the underlying CCE structure. This intermediary layer simplifies the overall system by providing a standardized interface between control channel processing and physical resource management.

The patent performs CCE interleving before VRB mapping, which preliminarily distributes control channel elements across frequency resources. This preliminary action ensures that even before the final VRB-to-PRB mapping, the R-PDCCH components are already spread across different frequency locations, providing inherent frequency diversity that simplifies the subsequent mapping stage while maintaining robustness against frequency-selective fading.

The patent enables dynamic selection between localized and distributed VRB mapping modes based on channel conditions and service requirements. By changing the mapping parameter (localized vs. distributed) adaptively, the system can optimize frequency diversity when needed while reducing complexity when channel conditions are favorable, thus resolving the contradiction between diversity gain and allocation complexity.