Large system error probability of multiuser decision feedback receivers

The large system limits of the probability of error for multiuser decision feedback detectors (DFDs) are evaluated for synchronous CDMA. Both successive (S-) and parallel (P-) DFDs are considered, where the filters are optimized according to the minimum mean squared error (MMSE) criterion. A comparison of the analytical results with simulation shows that the large system results accurately predict the performance of systems with a spreading gain /spl ges/128 over a wide range of error rates. The results also show that the P-DFD error rate approaches the single-user bound at high signal-to-noise-ratios (SNRs).