A threshold-based linear parallel interference canceller on fading channels

We obtain closed-form expressions for the bit error rate (BER) of a conventional linear parallel interference canceller (LPIC), where the interference from all other users is estimated and cancelled on Rayleigh fading and diversity channels. We also propose an improved LPIC scheme which cancels the interference from only those users whose instantaneous SNRs exceed a certain threshold on Rayleigh fading channels. We obtain the optimum threshold by optimizing an approximate expression for the SIR at the canceller output. We show that the proposed threshold-based LPIC scheme performs better than the matched filter (MF) detector as well as the conventional LPIC scheme.