Hybrid Interference Cancellation for Stationary and Non-Stationary Users in DS-CDMA
Monica Khanore, Srija Unnikrishnan · 2019
In addition to the Multiple Access Interference (MAI) caused by the loss of orthogonality of the spreading codes while transmission, the multi path propagation of the user signals further aggravates the interference which adversely affects the BER performance of the DS-CDMA system. Another factor contributing to the degradation of performance is the Doppler shift in the carrier frequency. In this paper the performance of the modified hybrid interference cancellation scheme is investigated in the presence of MAI, multipath propagation as well as Doppler shift in the Rayleigh fading environment. The scheme uses the Least Square (LS) channel estimation method. The interference cancellation scheme and the detection technique used avoid the need for the use of RAKE receiver for data estimation. The interference canceller is shown to exhibit tolerable BER in the presence of Doppler shift.