A novel narrowband interference canceller for OFDM systems

Narrowband interference (NBI) will degrade the performance in an OFDM system not only on the overlapped subcarriers, but also on the nearby subchannels due to the spectral leakage effect of DFT demodulation. In this paper we proposed a novel NBI suppression method in the case that NBI is caused by a narrowband digital communication system. We estimate the "transmitted data" of NBI signal and reconstruct its waveform, by measuring interference information on certain unmodulated subcarriers. And then subtract estimated disturbance in frequency domain. Simulation results show that this method can achieve an average SINR gain about 6 dB on a multipath fading channel, when the interference has equal power with the desired signal and twice bandwidth of an OFDM bin. With less bandwidth of NBI, more performance gain will be obtained.