Evaluation of BER Performance for M-Ary QAM OFDM Through Wireless Channel by Controlling PAPR at the Transmitter

The implementation of FFT in OFDM system may provide many advantages, such as the bandwidth becomes more efficient and the signal performance over fading channel is better than single carrier signal. However, the PAPR of the signal is high and it can reach 10 dB, which is equivalent to a peak power that is 10 times higher than the average power. This way, the usage of FFT-based OFDM is not very efficient, especially in terms of power consumption at the transmitter. In this paper, a simulation was done to evaluate the BER performance of the signal with the implementation of several PAPR reduction techniques, such as the wavelet transform, Partial Transmit Sequence (PTS) technique, and also the clipping technique. The implementation was done with the 16 QAM and 64 QAM, and also the signal was sent through Rayleigh fading channel. The result shows that for 16 QAM, the best result is achieved by using db1 with PTS technique. With Eb/No value of 20 dB, the BER can be 10−3, which is 7 dB better than the normal FFT-based OFDM system. As for 64 QAM, the best result is achieved by the usage of normal db3 without PTS nor clipping technique. With Eb/No value of 24 dB, the BER can be 10−3, which is 4.5 dB better than FFT-based OFDM system.