Precise bit error rate calculation for asynchronous DS-CDMA in Nakagami fading

Abstract

Accurate bit error rate calculation is considered for a binary, direct sequence spread spectrum multiple access system using conventional matched filter receivers and long code sequences in flat fading Nakagami channels. To this end, a closed-form expression for the characteristic function of a sum of multiple interfering signals is found. The exact average bit error rate is expressed as a single integral with a well-behaved integrand function. Numerical results obtained from the new accurate bit error rate expression are compared with the standard Gaussian approximation.