SIMPLEST PHASE NOISE MITIGATION TECHNIQUE IN OFDM SYSTEM

In Orthogonal Frequency Division Multiplexing Communication systems, the local oscillator used for the upconversion and down-conversion at the transmitter and receiver respectively introduces phase noise which causes two effects, common phase error (CPE) and inter-carrier interference (ICI). OFDM is one of the futures of wireless communications system, but exhibit great sensitivity to the phase noise and the time-varying propagation channel, inter-channel interference (ICI) result to the loss of orthogonality among subcarriers and common phase error (CPE) causes the rotation of constellation of the OFDM signal. Due to the presence of phase noise, produced by the local oscillator at the transmitter and receiver result in reduction of signal to noise ratio (SNR), and hence reduce the bit error rate (BER) and data rate. There are various methods of high complexity of phase noise mitigation already proposed in the literature. In this paper simple technique has been proposed. The computer simulations of the proposed scheme shows how effectively the effect caused by phase noise gets mitigated and improve the BER of OFDM systems..