New Remapping Strategy for PDCCH Scheduling for LTE-Advanced Systems

Abstract

In LTE-A, efficient Physical Downlink Control Channel (PDCCH) scheduling is fundamental to ensuring not only users' Quality of Service (QoS) but also bursty data channels. However, the limited resource available for PDCCH has proven to be a major issue that hampers users' scheduling. By principle, every user equipment (UE) admitted into the network is expected to be scheduled by the control channel prior to gaining access to data channel's resources (i.e. Physical Resource Blocks-PRBs). However, the limited PDCCH resources in traditional systems usually result to some UEs being deprived from accessing PRBs because they have not been scheduled for resource access by PDCCH. This situation is a major connectivity challenge in LTE-A systems. As such, we have proposed a new remapping strategy for PDCCH resource scheduling based on linear transformation matrix. Our scheme remaps the users' search spaces using a transformation function derived from their previous search spaces and the available resources in order to efficiently address PDCCH resource utilization issue. Extensive simulation results show that our new scheme is able to reduce UEs' average blocking probability and as well improve PDCCH resource utilization. Notwithstanding this enhancement, our scheme still maintains the decoding procedure and search space concept in LTE-A systems. Terms — Physical downlink control channel (PDDCH), aggregation level, search space, control channel element, u ser equipment (UE).