Performance Analysis of Amplify and Forward Cooperative Relaying Protocol in Wireless Communication System

Cooperative relaying has been well appreciated to be a key concept of future wireless systems capable of yielding high network reliability and significant error rate reduction. However, in such paradigm of communication, the total limited power may be wasted without providing minimum performance requirements such as network lifetime if it is not well allocated between the cooperating nodes in an efficient way. In this work, we mainly address the problem of network lifetime limitation in wireless relay communication system by developing optimal power allocation techniques. In the communication scenario, a source sends information to a destination with the help of multiple relay nodes operating in amplify-and-forward relaying protocol. As a parameter of measurement, we particularly address the symbol error rate (SER) performance for MPSK signal using the concept of moment generating function. Due to the complexity of the closed-form SER expression, we then find a tight corresponding lower bound to show useful insights in terms of analysis. Next, we develop a cooperation strategy where only a best relay that maximizes the end-to-end signal-to-noise ratio assists the transmission to further improve the performance of the previous system. In addition, numerical results are presented to validate the theoretical analysis.