Enhanced Symbol-Level Interference Cancellation for PDCCH of 3GPP LTE/LTE-A

In cellular communication systems, such as 3GPP LTE (3rd Generation Partnership Project Long Term Evolution)/LTE-Advanced, mutual co-channel interference from neighboring cells may significantly jeopardize the performance of all downlink physical channels, especially for receivers located at the cell-edge. A conventional approach to cope with those interference issues relies on coordination of neighboring cell transmissions. However, the design of Physical Downlink Control Channel (PDCCH) of LTE/LTE-A is not flexible enough to fully support transmitter-based inter-cell interference coordination (ICIC). Therefore, a more general receiver-based approach to suppress co-channel interference on PDCCH is being considered for LTE/LTE-A. This paper proposes an enhanced iterative symbol-level inter-cell interference cancellation (SLIC) receiver designed for PDCCH. Compared to conventional SLIC, the proposed method provides more robust PDCCH link-level performance in scenarios with amplitude ambiguity of the serving and interfering signals which can occur in LTE/LTE-A systems due to the transparent, i.e., without any network signaling assistance to the user, power control on PDCCH. From simulation of PDCCH in LTE/LTE-A systems, we show that the proposed SLIC receiver provides substantial performance gains over the conventional SLIC receiver under typical PDCCH interference conditions.