PERFORMANCE ANALYSIS OF OFDM WITH QPSK USING AWGN AND RAYLEIGH FADING CHANNEL

Wireless technologies have gradually become more and more involved into everyday life. Among multicarrier transmission techniques, Orthogonal Frequency Division Multiplexing (OFDM) is the most popular one that uses parallel data streams. Compared with single carrier modulation, OFDM has many advantages as immunity to impulse interference, high spectral density, robustness to channel fading, resistance to multipath, much lower computational complexity. However, OFDM has some major drawbacks to implement it in practical telecommunication systems. Some of them are that OFDM signal suffers Packet loss, Bit loss, Bi t Error Rate (BER), Signal to Noise Ratio (SNR). In this paper all these terms are discussed and all the four parameters are compared using AWGN and Rayleigh fading channel by changing the phase of some of the subcarriers using QPSK in OFDM modulation. Results shows that in case of Rayleigh fading the Packet loss is.4574, Bit loss is 1.77e+004, Bit Error Rate is.520444651and Signal To Noise Ratio is 2.6dB.Where as in case of AWGN channel Packet loss is.36355,Bit loss is 28061,Bit Error Rate is.36355980514096 and Signal to Noise Ratio is 3.2 dB. Which shows that Rayleigh fading channel is better than the AWGN channel. The simulation is done on MATLAB softwar