Search space design of enhanced physical downlink control channel for long term evolution advanced system

This paper focuses on investigating the search space design of Enhanced Physical Downlink Control CHannel (EPD-CCH), which is introduced in Long Term Evolution-Advanced (LTE-A) system to increase the capacity of the downlink control channel. Since EPDCCH is frequency-division-multiplexed with downlink data channel, resource utilization efficiency is a very important issue in addition to blocking probability. This paper proposes the innovative methods of locating the search spaces of EPDCCH with different transmission schemes, i.e. distributed transmission and localized transmission, considering the UE complexity, the capacity of control channel and the impacts on Physical Downlink Shared CHannel (PDSCH). By simulation results, it is proven that the proposed methods could get higher resource utilization and lower blocking probability while maintain the same UE complexity in blind decoding.