Mitigating intercarrier interference by rotating received symbols in OFDM communication systems

For intercarrier interference (ICI) due to frequency offsets, this paper studies an ICI self-cancellation scheme for combating the impact of ICI on OFDM systems. Its basic idea is symbols rotation and interference self-cancellation. At the transmitter, original symbols are mapped into one special symbol block, and then it is transmitted as a conventional OFDM system. Received signals are divided into two paths at the receiver. The each sampled data of the received signal at one path is multiplied by relevant sub-carriers, respectively. Later, these results are subtracted from those of the relevant signal at another path, and then the resultant signals are demodulated to obtain the estimation of original data symbols as a conventional OFDM system. Analysis results show that the ICI contained in the received signals can be effectively reduced by using the scheme, and the Carrier-to-Interference power Ratio (CIR) of the scheme is obviously better than that of a conventional scheme and another similar scheme. Similarly, simulation results show Bit Error Rate (BER) performance of the scheme is better than that of two other schemes.