MINIMIZING MULTIPART FADING IN CELLULAR NETWORK USING ANTENNA DIVERSITY TECHNIQUE

Abstract

This thesis aims at reducing multipath fading in cellular network using antenna diversity technique. In this thesis, several causes of multipath fading were considered. The Bit Error Rate (BER) of the investigative network was investigated before and after antenna diversity. Experiments were done to show signal reception improvements with space diversity. Simulation result shows that antenna diversity on the investigative network gave a BER of 10-2 to 10-3 which shows that antenna diversity has reduced the effect of multipath fading. Multipath fading is a critical challenge in cellular networks, significantly degrading signal quality and overall system performance. It occurs when transmitted signals reach the receiver via multiple paths due to reflections, diffractions, and scattering caused by obstacles like buildings and terrain. This phenomenon leads to constructive and destructive interference, resulting in rapid fluctuations in signal amplitude, phase, and delay. To mitigate these adverse effects, antenna diversity techniques have been widely employed. Antenna diversity involves using multiple antennas at the transmitter, receiver, or both, to provide alternative signal paths and improve the probability of receiving a strong signal.This paper explores the use of antenna diversity as an effective method to reduce multipath fading in cellular networks. Various diversity schemes such as spatial diversity, polarization diversity, and pattern diversity are analyzed with respect to their ability to enhance signal reliability and network capacity. The study discusses how antenna diversity exploits the spatial decorrelation of fading signals by combining signals from multiple antennas using techniques like selection combining, maximal ratio combining, and equal gain combining. These methods significantly improve the signal-to-noise ratio (SNR), reducing the fading margin and enhancing communication quality. Simulation results demonstrate that antenna diversity considerably reduces the depth and duration of fades, leading to improved bit error rates (BER) and overall system robustness. The paper concludes that antenna diversity is a cost-effective and practical solution for mitigating multipath fading, thereby improving the performance and reliability of modern cellular networks.