MMSE interference suppression for multicarrier DS-CDMA in frequency selective channels

We integrate the multicarrier (MC) signaling technique and a minimum mean-squared error (MMSE) receiver to design a MC DS CDMA system with the capability to suppress both multiple access interference and multipath interference. We employ the correlated subcarrier model to analyze the average probability of error of the system when operating in a frequency selective Rayleigh fading channel, and compare the results with those obtained when the MC-RAKE system operates without the MMSE. The new system is shown to successfully suppress near-far multiple access interference without requiring knowledge of other users' spreading codes, timing, or phase information, while, at the same time, yielding a diversity combining gain. Also, the tradeoff among the number of subcarriers, the number of multipaths, and the number of weights in the MMSE receiver is shown in the results.