ABSTRAKSI: Kata Kunci : ABSTRACT: Multiuser Detection is the most important aspect on DS-CDMA system. The capacities of DS-CDMA with the conventional receiver limited by multipath fading, Multiple Access Interferensi (MAI) problem, and near-far problem. This research study the performance of MUD decorrelator compared to a conventional receiver at perfect synchronization condition and also imperfect synchronization, consequence the saturation value of decorelator is also increase, it is mean that decorelator system have a good performance to error synchronization.
Rake Receiver used to overcome the problem of multipath fading and decorrelator detector to overcome the problem MAI. Decorrelator detector performance limited by uplink direction and perceived with the computer simulation posed with the graph of Bit of Error Rate ( BER) to Signal to Noise Ratio ( SNR) and BER to error synchronization (20Tc). In this simulation used synchronize DS-CDMA system and BPSK modulation, that transmitted to canal with multipath fading and Additive White Gaussian Noise ( AWGN) characters on the receiver.
At perfect synchronization, decorrelator detector better than conventional performance, goodness in addition of SNR and also speed of user, performance of decorrelator detector still better than conventional during its error synchronization below dot saturation value. Performance of Decorrelator detector will much the same or can be worse than conventional if the error synchronization increased again.Keyword: MUD,decorrelator