Relay Selection Schemes for Cooperative Communications Systems Sensor Networks

Due to being so effective to mitigate the fading effect of wireless channels relay networks have received so much attention recently. Especially because relays are typically small, power limited and low cost and also can remove the problem of attenuation of signal due to propagation loss. Moreover increasing the number of relays improves the system performance and also using more power. The system efficiency can be enhanced by selecting relays in better conditions. In this paper single and multiple relay selection schemes is proposed applying Principal Component Analysis (PCA) method. The main idea of PCA method is selecting relays according to the eigenvector corresponding to the largest eigenvalue of channels from source to the destination. The PCA method provides an acceptable tradeoff between better power and Bit Error Rate (BER) performances. The higher efficiency is achieved by Appling PCA which demonstrated in power performance and this management of total power usage makes relay networks more practical.