A Low Complexity Receiver with Interference Cancellation for Power-Controlled MC-CDMA Downlink Transmissions

We consider the downlink of a power-controlled MC-CDMA system in which the near-far effect limits the performance of single-user receivers and calls for interference cancellation (IC)-based schemes. The latter provide enhanced error rate performance but are not suited for downlink applications due to their relatively large complexity. To overcome this problem, we present a novel reduced-complexity IC- based detector in which interfering signals are canceled provided that their estimated power exceeds a given threshold. In addition to the channel response, the proposed scheme requires knowledge of the amplitudes of the users’ signals. The latter are estimated using two different methods that exploit some pilot blocks placed at the beginning of the downlink frame. Numerical results are given to highlight the effectiveness of the proposed scheme and to make comparisons with other existing IC-based solutions.