Performance Limitations of a SIMO OFDM Wireless Link Impaired by Carrier Frequency Offset, Phase Noise and Rayleigh Fading

摘要

An analytical approach is developed to evaluate the Bit Error Rate (BER) performance of an OFDM wireless link over a faded channel impaired by Carrier Frequency Offset (CFO) and phase noise. The analysis is further extended to an OFDM system with receive diversity taking into consideration the effects of above system impairments. The analysis is developed for SIMO OFDM to find the expression of the unconditional bit error rate of the wireless link with Rayleigh fading assuming Gaussian probability density function of the CFO and phase noise. Analysis is carried out for both Maximal Ratio Receiver Combining (MRRC) and selective combining techniques. BER performance results are evaluated numerically following the analytical approach. The results are depicted in terms of BER versus Signal to Noise Ratio (SNR) with different fading variances and for different values of CFO and phase noise variances. Results show that the system BER is highly deteriorated due to fading, CFO and phase noise. Thus, there is significant penalty in signal power at a given BER. System BER performance results are evaluated with different receiver diversity combining techniques. It is noticed that there is significant improvement in system performance increasing the receiver sensitivity due to the application of the receive diversity techniques.