Performance of the multi-stage variable group hybrid interference cancellation scheme with timing and phase errors

The variable group hybrid interference cancellation (VGHIC) scheme proposed in [KW Ang et al., 1999] outperformed both the successive (SIC) and parallel (PIC) interference cancellation in a system with perfect fast power control, and also in a system without fast power control. However, the comparison was done under the assumption that the timing and phase estimations were perfect. In practical systems, these parameters are not perfectly estimated. In this paper, we study the effect of phase and timing errors on the bit error rate (BER) performance of the VGHIC and its multi-stage structure. A performance comparison with the SIC, PIC and the conventional matched filter receiver is also presented. Simulations show that the VGHIC maintains an overall performance advantage over the SIC and PIC even with high estimation errors. However, the performance gain from using the multi-stage structure diminishes rapidly as the estimation errors are increased. It is observed that the rapidly as the estimation errors are increased. It is observed that the VGHIC, as well as the PIC and SIC are more tolerant of phase errors than timing errors.