Fractionally spaced decision feedback joint detection for multitone CDMA systems

In the present paper we consider a fractionally spaced decision feedback joint detector for multitone CDMA systems. We first derive the structure of the receiver for an MMSE criterion. Then we evaluate the BER achieved by this detector for BPSK modulation in steady-state conditions. We consider an asynchronous scenario where the signal of each user propagates over a two-path channel. The resistance of the detector against timing errors is studied and the resistance against a near-far scenario is also demonstrated.