An Ordered Interference Cancellation Detection Scheme for Oversampled OFDM System in Doubly Selective Fading Channels

This paper proposes a linear ordered successive interference cancellation (OSIC) detection scheme for the oversampled OFDM system to improve the diversity gain and decrease the interference over the doubly selective fading channel. In the proposed scheme, the received OFDM signal is primarily processed by an oversampling module and a FFT module, then the processed data symbols are detected one by one in the order determined by comparing the post-detection signal-to-interference and noise power ratio (SINR) of the symbols, the symbol with the largest SINR is first detected based upon the MMSE and then subtracted from symbol sets, the rest symbols are reconstructed and perform the above operations until all symbols are detected. Simulation results show that the proposed method outperforms the suboptimum Doppler domain block decision feedback scheme by about 2dB for normalized Doppler shift F_d T_o= 0.5, the proposed method is able to effectively reduce the residual interference and error propagation in the low complexity, moreover, it is further suppress ICI and obtain the diversity embedded in fast time-varying channels.