Performance Evaluation of PAM-4 and PAM-2 Modulation Techniques using MATLAB

Abstract

Two Levels Pulse Amplitude Modulation techniques (PAM-2) is failing to cope with the increase in appetite for data and higher data rate with respect to noisy channel. Hence, Four Levels Pulse Amplitude Modulation techniques (PAM-4) was developed. PAM-4 is said to enable two times the data rate as compared to PAM-2. PAM-4 has its pros and cons as compared with PAM-2. This paper compares the performance of Two Levels Pulse Amplitude Modulation technique to Four Levels Pulse Amplitude Modulation technique. The communication system was modeled using Simulink R2016b, the signal passed through an Additive White Gaussian Noise (AWGN) Channel and eye diagram scope was adopted to evaluate the corresponding signal. The study compared eye diagram to evaluate both PAM-2 and PAM-4 at same channel condition. Bit error rate (BER) analysis of the two signals were studied and the results for the corresponding signals were compared. It was observed that the performance of PAM-2 surpasses PAM-4 in terms of the bit error rate analysis. The study shows similar characteristic for Symbol Error Rate Probability curve. The result revealed that PAM-4 is more susceptible to noise than PAM-2.