Low-complexity linear group-SIC detectors

In this paper, we consider a linear group polynomial expansion successive interference cancellation (GPE-SIC) detector in a synchronous CDMA system. It is a hybrid detector, which combines parallel and successive cancellation techniques in order to extract the advantages of both schemes. We use the fact that even if the crosscorrelation matrix of the system is not diagonal dominant, the sub-matrices corresponding to different groups can be forced to be diagonal dominant by suitable grouping of users to approximate the decorrelator/MMSE detector by a low-complexity polynomial expansion detector. The latter is computationally very efficient if the crosscorrelation matrix of users within the same group is diagonal dominant. Simulation results showed that the (GPE-SIC) detector has the same performance as the linear group decorrelator successive interference cancellation (GDEC-SIC) detector but with low-computational complexity.