The present work aims to illustrate the improvement that turbo encoding / decoding algorithms can bring to a multiuser detection system, evaluated in terms of Bit Error Rate (BER). Extended simulations have been performed for conventional multiuser detection algorithms and are still under study for other algorithms, like the optimal, the MMSE and the classical MMSE ones. Simulations have been performed in both optimal conditions and imperfect ones, like non-equal power of users and non- zero correlations between them and for different number of users. Several interesting conclusions have been highlighted with respect to parameters influence on overall system performances.