BER performance of multicarrier DS-CDMA systems over generalized fading channels

We study the performance of a multicarrier DS-CDMA system proposed by Kondo and Milstein (see IEEE Trans. Commun., vol.COM-44, p.238-46, 1996) when the various subbands undergo a generalized type of fading. We consider the average bit-error-rate of such systems in the absence and in the presence of partial band interference, and compare the results with that of a single carrier RAKE system. The final expressions are expressed in a simple form which can be readily computed numerically and offer therefore a useful analytical tool for the accurate performance evaluation of various systems operating in a wide range of fading environments. The mathematical formalism is illustrated by applying the analysis to the performance of a multicarrier DS-CDMA system over Nakagami-m fading. Numerical results confirm that multicarrier systems outperform single carrier ones in the presence of strong interference. Furthermore, the relative difference between the two systems tends to increase as the amount of fading decreases.