An improved BER calculation for nonlinear successive interference cancellation [DS-CDMA systems]

In this contribution, an algorithm for calculating the bit error rate (BER) of a nonlinear successive interference canceller (SIC) in a direct sequence-code division multiple access (DS-CDMA) system was presented. The model of our algorithm was actually originated from a notion proposed by Frenger, et al. (Elect. Lett. vol.35, no.18, p.1572-1573, 1999) for a binary phase shift keying (BPSK) DS-CDMA system. However by modifying that algorithm so as to exploit the characteristics exhibited by the nonlinear SIC, we managed to improve the accuracy of each user´s computed BER. Furthermore, our modified algorithm can also be applied in certain anomalous conditions, such as imperfect recreation of a user´s signal. Our improved algorithm is then further extended, in order to calculate the BER of each user for a 16 quadrature amplitude modulation (QAM) DS-CDMA system. In all cases, it was shown that the BER for each user computed by our algorithm nearly matches with that obtained by simulation.