The fading channel problem and its impact on wireless communication systems in Uganda

Abstract

Recent advances in radio communications, signal processing, and computer technologies have made wireless networking for data-communication systems an achievable reality. Wireless communication for data networks is not only limited to outdoors systems, but has also extended to an attractive application referred to as indoor wireless local area networks (WLAN). The advantages of wireless networks are that they allow for mobility of users and rewiring is unnecessary when a user of a WLAN moves, which is especially important for users of portable data terminals. Because the WLAN can operate in indoor environments, high-speed data transmission is possible without requiring an unrealistic amount of transmitter power. The explosive growth of wireless systems, coupled with the proliferation of laptop and palmtop computers and mobile phones, indicates a bright future for wireless networks, both as stand-alone systems and as a part of the larger networking infrastructure. Many technical challenges remain in designing robust wireless networks that deliver the performance necessary to support the emerging applications. Multipath propagation is the most challenging problem encountered in a wireless-data-communication-link design process. Due to the complexity of the fading phenomena, engineers currently depend more on simulation techniques to predict the effects of the various parameters involved. This chapter discusses the multipath problem, the physical causes of fading, and mitigation measures applied in the Uganda cellular communication systems environment. It also presents a mathematical model for fading and characterizes it as a stochastic process.