An Efficient Receiver for Ici Cancellation in Ofdm Systems Based on Prcc Scheme Using Mmse Equalizer

This paper presents a cyclic prefixed conjugate transmission technique with adaptive receiver to cancel out the ICI in OFDM systems using MMSE equalizer. The receiver design is based on the phase rotated conjugate cancellation (PRCC) concept , where two individual phase rotations are employed on the two receive paths, rather than only one phase rotation is adopted for the two transmit paths in the PRCC scheme. Cyclic prefix increases signal spacing and makes the signal more robust to ISI. The two phase rotations are chosen properly using the criterion of maximizing the carrier-to-interference ratio such that an additional phase distortion on the detected symbol could be completely removed. Block least mean-squared algorithm is applied to adaptively update the two phase rotations with the frequency offset variation. BER performance of the proposed method with MMSE and Zero Forcing Equalizer is compared. Simulation results shows that MMSE equalizer based approach can further improve the performance of proposed scheme at low to medium SNRs. Keywords— Inter Carrier Interference (ICI), Adaptive Receiver, Frequency Offset, OFDM, MMSE, Block Least Mean Square Algorithm.