Frequency domain CFO compensation for FBMC systems

The frequency-domain compensation of the deleterious effects introduced by the residual carrier frequency offset (CFO) still present on the received signal after rough time-domain compensation in a filter bank multicarrier (FBMC) receiver is considered. The compensation method depends not only on the particular FBMC modulation technique but also on the chosen receiver structure. The paper is dedicated to the case where the recently proposed frequency-despreading receiver, one of the most promising solutions, is used in the OFDM/OQAM transceiver. Specifically, this receiver exploits some samples of an extended FFT and, as shown in the paper, it can nearly perfectly compensate the CFO effects on the received signal by adapting the weights of the linear combination of the considered samples. A detailed analysis of the frequency-despreading structure and of the proposed CFO-compensation technique is presented by using as performance measure the signal-to-interference ratio and the bit-error-rate.