Performance evaluation of the Enhanced Physical Downlink Control Channel in a LTE network

In 3GPP LTE Release-11 the Enhanced Physical Downlink Control Channel (EPDCCH) has been specified for downlink and uplink radio resource assignment notifications to User Equipments (UEs). EPDCCH has been designed to overcome several limitations of the Physical Downlink Control Channel (PDCCH) used in LTE Release 8-10. Some of the important design objectives of EPDCCH are: increased capacity for DL and UL assignments by exploiting frequency selectivity and beamforming, greater flexibility of dynamic allocation of control channel resources, and enabling frequency domain inter-cell interference co-ordination in heterogeneous network deployments. In this paper, we compare the performances of PDCCH and the LTE Release-11 EPDCCH by system level simulation. The performance evaluation results indicate that, in low user mobility and frequency-selective channel condition, EPDCCH can derive significant benefits from frequency domain scheduling and UE-specific beamforming; using EPDCCH instead of PDCCH, control channel blocking rate could be reduced, and a significantly larger number of users could be scheduled per subframe.