Mitigation studies of fading channels for mobile communications

Abstract

This project aims to study mitigation techniques to reduce the negative impact caused by fading channels. Nowadays, most human activities are supported by communication technologies, such as telework, telecommunication and so on. In addition, communication modules are also integrated into more advanced technologies to improve productivity and provide more helpful services like Internet of Things (IoT) and cloud computation. However, fading channels significantly degrade the performance of communication systems, causing trouble in humans’ normal life. Therefore, the study is conducted to mitigate its fading effect, which consists of four main stages. All experiments are completed on Matlab, and the Rayleigh fading channel is selected as the channel model. First, the technique of space diversity is studied and simulated to prove its ability to lower bit-error rates (BERs). In the second stage, the orthogonal frequency division multiplexing (OFDM) technique is studied, and its function is verified by simulation. Third, other techniques, including spread spectrum, equalizer and channel coding, are also analyzed and simulated. The final stage is to establish the final mitigation system adopting all mitigation techniques studied in the previous stages. Two kinds of systems are built because two choices of space diversity are possible. After comparing, the final system that uses 1×4 SIMO and all other mitigation techniques has the best effect in mitigating the negative impact of Rayleigh fading, which is the biggest achievement of this project.