An Improved MIMO PCC OFDM System with Reduced Sensitivity to Imperfect CSI

In this paper we propose an improved multiple-input multiple-output (MIMO) polynomial cancellation coding (PCC) orthogonal frequency division multiplexing (OFDM) system. In this improved system, PCC OFDM symbols are transmitted from different antennae with different time offsets. At the receiver these symbols are demodulated using each of those time offsets. Time offsets substantially reduce the power of the interfering signal relative to the wanted signal at the PCC OFDM demodulation stage. The improved system has significantly reduced sensitivity to imperfect channel state information (CSI) and also retains the insensitivity of normal PCC OFDM to frequency offsets. Results are presented for the improved system with (2, 2) MIMO in flat Rayleigh fading channels. It shows that the improved system has a lower bit error rate (BER).