A simple ICI mitigation method for a space-frequency coded cooperative communication system with multiple CFOS

A cooperative system may have both timing errors and carrier frequency offsets (CFOs) from relay nodes. To combat timing errors, space-frequency (SF) coded OFDM system has been recently proposed for cooperative communications to achieve both full cooperative and multipath diversities without the time synchronization requirement among relay nodes. In this paper, we consider the signal detection problem in an SF coded OFDM system for cooperative communications where multiple CFOs may occur from relay nodes. By exploiting the structure of the SF codes that are rotational based in this paper, we propose a novel inter-carrier interference (ICI) mitigation method called the multiple fast Fourier transform (M-FFT) method. Simulation results illustrate that for the same symbol error rate (SER) level, the M-FFT based detection methods require less computations than other classic approaches.