Effects of Dispersion and Phase Noise on QPSK and QAM System: Performance and Compensation Techniques

This paper investigates the effects of dispersion and phase noise on quadrature phase shift keying (QPSK) and quadrature amplitude modulation (QAM) systems, as well as their compensation techniques, which are two fundamental modulation schemes widely used in digital communication. The motivation for this study is the growing demand for high-speed and reliable data transmission, which requires a deeper understanding of the impact of these damages on system performance. Through computer simulation, this work aims to gain a deeper understanding of the performance degradation caused by dispersion and phase noise, and to explore compensation techniques that can mitigate their adverse effects. We have discovered the impact of AWGN, dispersion, and phase noise on signal transmission and their manifestation on constellation diagrams. At the same time, compensation technology was used to compensate for dispersion and phase noise, which to some extent restored the distorted signal. Meanwhile, the BER-SNR curves of fibers with different linewidths under the influence of AWGN, dispersion, and phase noise were also explored to determine how to improve the bit error rate, enhance system performance, and achieve optimal communication performance of fibers.