The Study on Diversity Order of CD Networks based on Amplify-and-Forwards

In high SNR regime, diversity order is a performance metric which indicates how fast the error probability decays with SNR. This paper study the cooperative behavior of cooperative diversity (CD) networks based on amplify-and-forward (AF) protocol from the point of view of diversity order and explain the mechanism of obtained diversity order of several types of CD networks. The method we employ is much easier than the analysis approach used before. As a result, the obtained diversity order is equals to the number of independent paths which is combined at destination terminal. Numerical result verifies our conclusion further. The analysis method this paper presents can be easily utilized to analyze diversity order in many kinds of CD networks. Although achieving the exact error probability of these CD networks is a very difficult task, we can evaluate the asymptotic performance of these networks by the method this paper provides.