Performance of pre-FFT combining diversity OFDM receiver in the presence of co-channel interference

This paper proposes a novel pre-FFT (fast Fourier transformation) combining space diversity scheme for orthogonal frequency division multiplex (OFDM) systems for mitigating the degradation not only due to fading but also due to severe co-channel interference with low hardware complexity. Since the proposed diversity receiver requires only one discrete Fourier transform (DFT) processor to demodulate the OFDM signal, the proposed scheme can reduce the computational complexity. This paper derives the diversity weights for the proposed receiver in order to maximise the signal-to-noise plus interference power ratio (SNIR) after combining. Computer simulation results show that the proposed scheme can cancel the co-channel interference