Performance comparison of PIC and decorrelating multiuser receivers in fading channels

The decorrelating and parallel interference cancellation (PIC) multiuser receivers are among the most interesting multiuser demodulators for practical mobile communication systems. Thus, the performance of the decorrelating and the PIC multiuser receivers operating in frequency selective fading channels is compared. A decision-directed (DD) multiuser channel estimation based both on prediction and smoothing is presented. It is observed through computer simulations that from low to moderate SNRs, the PIC outperforms the decorrelator. The PIC is, however, more sensitive to channel estimation errors than the decorrelator, and at high channel loads it suffers from BER saturation, whereas the decorrelator does not.