Comparison of BER Performance for M-ary QAM and PSK on DWT-based OFDM System with PTS Technique Through AWGN Channel

Abstract

Modulation technique, such as QAM and PSK may provide wireless communication with bandwidth efficiency. They each have their advantages, especially when it comes to BER performance over a wireless channel. They increase the performance of the bandwidth when used along with the OFDM. The FFT usually used in the OFDM system; however, it significantly increased the PAPR. DWT-based OFDM system can be implemented to solve this, and PTS technique can further improve it. This paper aims to do a simulation comparing QAM and PSK's BER performance. Both modulation technique will have the order of 4, 8, 16, 64, and 256.Additionally, the bit order will be Gray-mapped. The signal is implemented in DWT-based OFDM system with PTS technique through AWGN channel. The result shows that the performance of 4-QAM is similar to QPSK. Then, 8-QAM is slightly better than 8-PSK, and as the order gets higher, the QAM shows a much better performance than PSK. The constellation diagram of QAM shows that the distance between each combination is constant for any order. PSK has a smaller distance; thus, it is very rational for QAM to perform better than PSK for the higher-order as 16-QAM, 64-QAM, and 256-QAM.