Low complexity frequency domain carrier frequency offset compensation for uplink multiuser FBMC receiver

This paper proposes a low complexity frequency offset compensation method for Filter Bank MultiCarrier (FBMC) waveforms in a context of Frequency Division Multiple Access (FDMA). The Carrier Frequency Offset (CFO) introduces Inter Carrier Interference (ICI) which is compensated in the frequency domain by the proposed algorithm. This method allows the factorization of the FFT computation for all the users in an uplink multiuser context. Based on the properties of FBMC modulation, a three steps method is proposed. First, a shift at the output of the FFT is realized to compensate a significant part of the CFO. A filtering followed by a phase correction is then performed to cancel the ICI. Simulations results show the effectiveness of the proposed strategy. A low complexity implementation based on a cascade of a small set of filters is also discussed and benchmarked.