AF relaying scheme for multiple relays-cooperative-turbo coded system

Improving the quality of the communication as well as the data rate is of utmost importance, particularly in adverse wireless conditions. In this paper, a scheme combining turbo coding and cooperative multiple relays techniques, comprising one source, one destination and multiple relays is proposed and studied. Because of text space limitation, only the Amplify and Forward (AF) strategy is investigated, thus the relay multiplies the received signal vector by an amplifying factor and forwards the resulting vector to the destination. We consider the using of specific signal constellations (e.g., Quadratic Phase-Shift Keying) in transmission, and develop practical turbo coding schemes to be used at the source node. Two Parallel Concatenated Convolutional Codes (PCCCs or turbo codes) are used at the source and a suitable information combining technique (MRC) is adopted at the destination node, assuming that all the relay-destination channels are well estimated at the destination. A great research interest has been dedicated to cooperative coding schemes, but the schemes combining multiple-relays cooperative diversity and turbo coding has not received such an interest.