Performance of the decorrelating detector for convolutionally coded DS/CDMA systems

In this paper, the performance of the decorrelating detector for a convolutionally coded DS/CDMA system is analyzed. Based on the union bound of the error probability of the Viterbi algorithm (VA) with soft or hard decoding, the upper bound of bit-error-rate (BER) of the decorrelating detector for convolutionally coded CDMA at higher signal-to-noise ratio (SNR) is derived. The performance of the detector at lower SNR is only given by computer simulations by reason of the heavy effect of the inferior BER of the decorrelating filter on the upper bound Analysis and simulations show that it is a simple and efficient method to evaluate the performance of such a receiver at higher SNR using the union bound. Simulations also show that great system gains can be achieved when decorrelating detection is used to combat the multiple access interference (MAI) over the conventional coded data transmission.