Effect of correlation between subcarriers of an MCM/DSSS communication system

The analysis of a combined multicarrier modulation/direct-sequence spread-spectrum (DSSS) modem carried out by Kondo and Milstein (see IEEE Trans. on Commun., 1995) in delay spread multipath is extended to include the effect of correlation between the DSSS subcarriers due to an exponential power delay profile. Analytical and simulation results show that additional diversity gain can be achieved with more subcarriers, but at the expense of multiple access capability. Eventually, an irreducible bit error probability (BEP) is approached as more subcarriers are used.