in this paper, we consider a cooperative cognitive radio network in which there is an ofdm primary link and multiple single carrier secondary links.the primary link is required to maintain its secrecy rate above a predefined threshold. if the secrecy rate requirement is not satisfied, the secondary system help primary link to maintain its secrecy rate requirement. in doing so, the secondary trans...

in this paper, we consider a cooperative cognitive radio network in which there is an ofdm primary link and multiple single carrier secondary links.the primary link is required to maintain its secrecy rate above a predefined threshold. if the secrecy rate requirement is not satisfied, the secondary system help primary link to maintain its secrecy rate requirement. in doing so, the secondary trans...

Cooperative communication has received tremendous interest for wireless networks. Most existing works on cooperative communications are focused on link-level physical layer issues. Consequently, the impacts of cooperative communications on network-level upper layer issues, such as topology control, routing and network capacity, are largely ignored. In this article, we propose a Capacity-Optimiz...

This article reviews progress in cooperative communication networks. Our survey is by no means exhaustive. Instead, we assemble a representative sample of recent results to serve as a roadmap for the area. Our emphasis is on wireless networks, but many of the results apply to cooperation in wireline networks and mixed wireless/wireline networks. We intend our presentation to be a tutorial for t...

In recent years, cooperative communications are widely studied. Cooperative communications can obtain the space diversity as multiple-input multiple-output (MIMO) systems. In cooperative communications, the relay method is important as decode-and-forward (DF) and decode-amplify-forward (DAF). The multi-relay cooperative communications can improve the system performance. In the multi-relay coope...

This Wireless channel while offering independence of movement also introduces un-reliability in the messages received at the destination. Various strategies have been introduced so far to mitigate the effects of the channel on the message received. In this paper, we give an introductory overview of cooperative communications, a new trend in this field of wireless Communications where the transm...

Cooperative vehicular communication systems are being developed to improve traffic safety and efficiency through the wireless exchange of information between vehicles and between vehicles and infrastructure units. The future deployment of cooperative active safety applications requires their prior extensive testing due to their critical nature and strict quality of service requirements. Such te...