Performance of a Decorrelator in Convolutionally Coded WCDMA Systems

Rapport, 2005

The objective of this paper is to study the performance of a linear multiuser detector (a decorrelator) in a convolutionally encoded wideband code-division multiple-access (WCDMA) system. The study, which is valid for a traditional detection scheme, where the decorrelator and the channel decoder work separately, shows that the single-user detector (the Rake receiver) performs better than the decorrelator at low signal-to-noise ratios (SNRs). The SNR range, in which the Rake receiver outperforms the decorrelator, is influenced by the error correction capability of the channel code and the load of the system. In particular, a WCDMA speech service is evaluated. Simulations show that the Rake receiver is superior to the decorrelator when targeting a required bit-error rate (BER) of 10^{-3}.