| Cooperative diversity is a technique recently proposed to mitigate channel impairments due to large-scale and small-scale fading, which can be applied to various wireless, including ad hoc and sensor networks. In this dissertation, the performance of a dual-hop amplify-and-forward (AF) cooperative diversity system is investigated. Two diversity combining techniques employed at the destination terminal, including maximal-ratio combining (MRC) and selection combining (SC), are considered. The outage performance of the system under four different fading environments, Rayleigh, Rician, Nakagami- m and Weibull fading, are analyzed. The signal-to-noise ratio (SNR) at the receiver is upper bounded. New closed-form expressions for the probability density function (PDF), cumulative distribution function (CDF) and the moment generating function (MGF) of the bounded SNR are derived. These statistical results are then applied to obtain the outage probabilities. Numerical results of the outage probabilities for different fading scenarios are examined to illustrate the advantage of cooperative diversity in terms of outage performance. The outage performance of the system in situations when the signals of different links undergo different types of fading and the situation when shadowing is present are also studied. The impact of power allocation between source and relay nodes on the performance of the system is also investigated. |
