Bit Error and Packet Error Probability for Rectangular Mary-QAM in OFDM Transmission System over Rayleigh Fading Channels

Abstract

Orthogonal frequency division multiplexing (OFDM) or multicarrier transmission has been shown to be an effective technique to combat multipath fading in wireless communications. It has been successfully used for HF radio applications and has been chosen as the standard for digital audio broadcasting and digital terrestrial TV broadcasting in Europe and high-speed wireless local areas networks.
This paper describes the concept behind parallel data transmission and the configuration of an OFDM transmitter and receiver when used four type of rectangular Mary QAM modulation (QAM, 16QAM, 64QAM & 256QAM). Two type of error evaluated (bit error rate BER & packet error rate PER) for two typical channels, AWGN channel & (one or two path) Rayleigh fading channels.
For AWGN channel, two curves are plotted (with & without) using guard time and compared with theoretical performance. While different curves are plotted for one path Rayleigh fading channels (with & without) using channel estimation and compared with theoretical performance. We explained how we configured the OFDM transmitter and receiver by using MATLAB computer software.
We discussed the results of our extended simulation of OFDM where we simulated the broadband WLAN system by using a pilot system assisted OFDM transmission system. We showed the effectiveness of the pilot system assisted OFDM transmission system for (one or two) path Rayleigh fading channel when using guard time is less than multipath delay spread or greater than multipath delay spread