Multicarrier direct-sequence spread-spectrum system performance in Doppler-spread Rician fading
R.E. Ziemer, Thaddeus B. Welch · 2003
A method for computing the bit error probability (BEP) of multicarrier modulated (MCM) direct-sequence spread-spectrum (DSSS) using differentially coherent phase-shift keying (DPSK) with equal gain combining in delay and Doppler-spread Rician fading is given. The accounting for the Doppler spread is based on Gauss-Chebyshev quadrature integration of the moment generating function of the decision statistic at the combiner output. The results show that as the specular-to-diffuse power ratio, K, increases and/or the maximum Doppler spread decreases the minimum BEP for optimum diversity, L (MCM carriers), decreases.