Performance analysis of multitone direct-sequence spread spectrum in the presence of carrier frequency offset

It is well known that accurate synchronization is more critical in multicarrier systems than in single carrier systems. Here we provide new analytical and computer simulation results for performance of MT-DS-SS signaling in the presence of imperfect carrier synchronization, modeled as frequency offset with Gaussian statistics. We investigate performance as a function of frequency offset standard deviation, the number of subcarriers and per-subcarrier processing gain. Random spreading codes are used, and we assume coherent BPSK modulation. Comparisons between simulations and analysis show excellent agreement, and also show the expected increased sensitivity of MT-DS-SS to frequency offset, compared with single-carrier DS-SS.