Co-Channel Interference Cancelation: Cross Coding vs. Beamforming

The performance of OFDM systems (e.g. IEEE 802.11g system) can severely degrade due to partial band interference (e.g. from Bluetooth devices). Therefore, we propose a novel cross coding scheme based on erasure codes to mitigate the effect of partial band jamming (PBJ). The key element of this coding scheme is to discard the part of channel that is corrupted by PBJ. By transmitting a packet over a single sub-carrier, the original data can be reconstructed with the assistance of erasure codes. In comparison with the Wiener beamforming technique, the proposed coding scheme has a power gain (i.e. at least 50% power saving) in the wireless receiver, and also has a performance gain in terms of the corrupted bandwidth and SIR. At SIR = 0 dB, it endures 1 MHz larger corrupted bandwidth than using beamforming, allowing one more Bluetooth device to coexist with the IEEE 802.11g system. Furthermore, it has a SIR gain of around 4 dB over the beamforming algorithm when only one Bluetooth interferes the IEEE 802.11g system (i.e. the corrupted bandwidth = 1 MHz).