Search Space Design in Enhanced Physical Downlink Control Channel for LTE-Advanced

In Long Term Evolution- Advanced (LTE-A) Release 11, an enhanced physical downlink control channel (ePDCCH)was introduced to increase the capacity of the physical downlink control channel (PDCCH), in order to support Multiple User-Multiple Input Multiple Output (MU-MIMO) and interference mitigation in heterogeneous networks. Design of the search space, in which control information is mapped, for the ePDCCH is an essential issue. Conventional search space designs suffer from low resource utilization efficiency and a high blocking probability. This paper presents a novel search space design. The proposed design introduces proper resource division in conjunction with a search space split. Simulation results show that the proposed design effectively improves the resource utilization efficiency and reduces the blocking probability.