The Comparative Performance of 16 QAM /BPSK -OFDM Scheme Over Frequency Selective Known and Unknown multipath besides AWGN channel

Abstract

In this paper, the communication Wireless channel is simulated comprehensively with utilizing orthogonal frequency division multiplexing (OFDM) technique for two different modulation scheme which are Binary Phase shift keying (BPSK) and Quadrature amplitude modulation (16 QAM). Also the bit error rate (BER) performance of different types of wireless communication channels were observed and evaluated. The simulation is basically carried out by MATLAB where, a wireless communication system with transmitter, channel and receiver are built and coded by. At transmitter side, 16 QAM modulation and OFDM technique were used to modify the input digital signal. Thus, the demodulator of 16 QAM and equalizer of OFDM technique were applied at receiver to recover the signal. Three different types of channel which are Additive White Gaussian Noise (AWGN) channel, known multipath channel and unknown multipath channel were used whose BER performance was obtained and evaluated. The BER is key point to indicate the performance of system is good or not. Moreover, the theoretical results of the BER under different channel were calculated and compared with the simulation results to make sure the simulation is correct. Hence, wireless communication system could have the best performance under AWGN channel among three channels. Also based on this observation, it would always be best to try and have a known multipath channel as a significantly better error performance can be made and the data rate does not necessarily have to suffer. In all the study carried out, there was a significant accuracies of 100% are investigated as all results came out as intended and an accurate positive analysis was able to be made as a result.