Spread Spectrum Technique Using Staggered Multi-tone

Filter-bank multi-carrier spread spectrum systems (FBMC-SS) provide a viable solution for communications in harsh environments where strong interferers may dominate portions of the spectrum. Thanks to spectrum localization of the individual sub-carrier bands in FBMC-SS, partial-band interferers can be easily removed. Previous studies of FBMCSS make use of filtered multi-tone (FMT), where sub-carrier bands are non-overlapping. This may simplify the tasks of carrier and timing synchronization as well as channel estimation, however, introduces a spectral footprint that may be undesirable in many applications. Instead, this paper adopts staggered multi-tone (SMT) filter banks that make use of offset/staggered quadrature amplitude modulation (OQAM) to remove any discernible footprint from the FBMC-SS spectrum. We propose a preamble design that facilitates development of carrier and timing synchronization algorithms as well as an effective channel estimation method. The performance of the proposed synchronization algorithms are evaluated through computer simulations. Moreover, the performance of the proposed channel estimator is bench marked against its respective Crammer-Rao lower bound (CRLB).