Performance of convolutional coded and uncoded DS/CDMA system in Nakagami fading channels

One of the interesting features of the DS/CDMA system is that in the forward link a pilot signal is used so as to provide a reference phase to a mobile station, while in the reverse link the pilot signal is not usually used due to the power efficiency problem. We investigate the performance of the convolutional coded DS/CDMA system with the noncoherent M-ary orthogonal modulation in multi-user environments over slow nonselective Nakagami-m fading channels with AWGN. The pairwise error probability that can be used to compute the upper bound of the coded system is derived. The performance of the DS/CDMA system with and without the convolutional codes are also compared, and we have observed that the convolutional codes satisfactorily compensate the degradation in multi-user situations over the Nakagami fading channel