Pre-combining advanced blind multiuser detector for time and frequency selective wireless channel

This paper deals with an adaptive multiuser detector for DS-CDMA (Direct Sequence Code Division Multiple Access) wireless communication systems, whose main features are low complexity and joint utilization of the time diversity and blind adaptive processing techniques. The proposed multiuser detector, defined as Pre-combining Advanced Blind Adaptive Multiuser Detector (PABA-MUD), a window reprocessing technique together with an original adaptation rule is used in order to improve performance for time varying environment. In particular, pre-combining of different replicas allows deriving a unique adaptive sequence even for multipath signals. The proposed detector shows remarkable near-far resistance and requires knowledge of the desired user´s signature waveform, timing and phase. No training sequence is needed. Receiver performance is expressed in terms of bit error rate (BER), which has been derived by simulations under the assumption of a time and frequency-selective Rayleigh fading channel.