INTERFERENCE REJECTION OF SIGNALS BY ADAPTIVEMINIMUM MEAN SQUARE ERROR CRITERION OVER RAYLEIGH FADING CHANNELS

Channel time-variation (or fading) is the major source of impairment in digitalwireless communications. This occurs due to mobility of the user or of the objectsin the propagation environment. The limited spectral bandwidth necessitates theuse of resource sharing schemes between multiple users. As the transmissionmedium is shared between the users, this leads to interference between the users.Sharing of resource results in interference such as multiple access interference.This paper deals with methods to study and mitigate such interference consideringRayleigh fading channels. There are various classes of fading conditions. The useof CDMA is under active research as a viable alternative to TDMA and FDMA.Performance in this system is limited by narrowband and multiple accessinterference. Various methods are used to mitigate them. But here, linear MMSEdetector is considered. MMSE technique results in interference rejection. Itsadaptive form is applied to Rayleigh fading channels, which are reflective andnondispersive. It results into better results than before.