An Interference-Blocking RAKE (IB-RAKE) Receiver for CDMA Communications Systems

Abstract

In this paper, a space-time RAKE (ST-RAKE) receiver with enhanced interference rejection is proposed for a CDMA communications system over multipath channels. The scheme involves three stages. An interference-blocking (IB) transformation is first developed for suppressing the strong interference, while the other signals retained. Optimum beamforming is then performed based on the IB transformed data to produce reception of signals of interest (SOIs) and rejection of strong interference. Finally, RAKE receiver is used to constructively collect the SOI energy. Since strong interference has been removed, RAKE receiver can effectively combine the SOIs, leading to performance enhancement as compared with the conventional ST-RAKE receiver. Numerical results illustrate the efficacy of the proposed interference-blocking RAKE (IB-RAKE) receiver.