Impact of time and carrier frequency offsets on the FBMC/OQAM modulation scheme

This paper presents a novel analysis of the sensitivity of an important class of filter bank multicarrier (FBMC) systems to time and frequency offsets. For the FBMC system under consideration the mapping for each sub-carrier uses offset quadrature amplitude modulation (OQAM) constellations. Assuming that the time offset (TO) and carrier frequency offset (CFO) are less than the symbol duration and sub-carrier frequency spacing, respectively, we derive exact analytical expressions of the interference power resulting from TO and CFO. Our theoretical results are confirmed by simulations for a large set of prototype filters. Furthermore, in the case of perfectly orthogonal prototype filters, we establish the link with a simple expression that up to now was left unused.