Comparative assessment of reconfigurable intelligent surfaces and relaying techniques with QAM imperfections

The thesis investigates the potential of Reconfigurable Intelligent Surfaces (RIS) to enhance wireless communication systems. Due to the increasing demand for data and the limitations of traditional cellular networks, innovative solutions like RIS are essential. The research focuses on optimizing RIS design parameters (element position and quantity) to improve Bit Error Rate (BER) performance. RIS is compared to traditional relaying techniques (Amplify and Forward, Decode and Forward) under various conditions, including different frequency bands and channel impairments. The findings demonstrate that RIS outperforms traditional relays in terms of BER, especially in non-line-of-sight scenarios. Additionally, the thesis analyzes the ability of RIS and relay systems to mitigate channel impairments like carrier frequency offset, timing offset, and phase noise in Quadrature Amplitude Modulation (QAM) systems. The goal is to determine the best approach for different communication scenarios based on factors such as network complexity, capacity, and robustness.