SNR and BER derivation and analysis of downlink OFDM systems with noisy fading Doppler channels

In this paper, we investigate the SNR and BER performance of an OFDM system under imperfect synchronization which is caused due to noise, Doppler shift and frequency selective fades in the channel. An analytical expression for BER is derived assuming BPSK modulation and numerical results are presented to show the effect and extent of the above channel impairments in OFDM downlinks.