Forward Transmission over a Multipath Faded Channel in a DS CDMA System

Abstract—the pseudorandom spreading sequence in the forward transmission in the IS-95 system is assigned only to individual base stations. To separate users, the system assigns orthogonal (Hadamard) sequences to each of them. In this paper, a different scheme for the forward transmission is considered. In this scheme pseudorandom sequences are u sed, instead of employing orthogonal spreading sequence for individual users. The effect of fade amplitudes, phase shifts, time-mismatching and AWGN on the detection process of Gold Sequence Spread Spectrum Signal (G SSSS) is considered. Key-words: Gold sequence, Rake receiver, Time-mismatching, QPSK-GS SS receiver.