Maximum ratio combining for OFDM systems with cochannel interference

In this paper, we investigate a receive diversity combining method for orthogonal frequency division multiplexing wireless local area network systems with cochannel interference. The scheme utilizes interference plus noise power (INP) to obtain the weighting factors for signal to interference plus noise power ratio (SINR) based maximum ratio combining (MRC). INP is estimated by using the correlation between the subchannel gains within the coherence bandwidth of the channel, which is caused by the limited delay spread of the multipath channel. Simulation results show that the SINR based MRC using the proposed INP estimator reveals greatly improved packet error rate performance compared to the signal-to-noise ratio based MRC that only considers white channel noise.