In advance radio communication, cooperative communication introduces a new method of collectively transmit information using antenna array with each terminal having single antenna in order to exploit spatial diversity in wireless fading channels. In this monograph the performance of important transmission protocols, amplify-forward, decode- forward and adaptive decode-forward in terms of symbol error rate have been demonstrated. In relay networks, specifically ad hoc or cellular networks user via cooperation enhances the quality of wireless communications link. In case of multiple relays, performance benefits of distributed space-time block codes over Rayleigh and Nakagami-m fading channels have been analyzed which ensures the performance improvement of data transfer in cooperative relay networks. The optimal power allocation algorithm between broadcasting and relaying phase has been introduced. Based on power allocation scheme the region of interest (ROI)-based scheme for image transmission is examined. Matlab simulations and Mathematica results are presented which show the good contribution to the latest research in the domain of cooperative communication.