Discrete Time Rake Receiver for Cooperative DS-CDMA Systems

In this paper, we propose to use the Discrete-Time Rake receiver for Cooperative DS-CDMA systems. We compare the Bit Error Rate (BER) performance of the Continuous Time, Discrete Time and Decorrelating Discrete Time Rake receivers (CTR, DTR, DDTR) using Decode and Forward (DF) relaying. The former receiver is the most used and consists in combining the output of correlators locked on the most significant paths. The DTR consists in a matched filter to the discrete equivalent model of the global channel resulting from the convolution of the impulse response of the transmitter shaping filter and the multipath channel. The DDTR is the optimal implementation of the DTR according to maximum a posteriori criterion.