In this paper, we study the transmit diversity of the cooperative relay system employing multiple-input multiple-output (MIMO) technology, especially for the Alamouti space-time block codes (STBC), over slow Rayleigh fading channel. The transmit diversity gain is achieved by STBC and cooperative technology. Maximum ratio combining (MRC) and maximum likelihood detection (MLD) are applied in the ...

An energy efficient adaptive rate cooperative MIMO selection scheme is proposed for uniform load distribution in the cluster based wireless sensor networks. The intrinsic data flow direction in multi-hop cluster based sensor networks causes uneven load distribution in the network. The transit clusters and the clusters near the base station carry more network traffic than the other clusters. Coo...

Wireless Mobile Communications rely on a host of techniques, all related to one goal, sending the most possible information accross a link or a network. In recent years, both spatial and multiuser diversity have proven to be key techniques to achieve this goal. These two diversity dimensions can be exploited by the use of multiple antennas and/or the use of multiple terminals sending at the sam...

We consider a scenario in which a sender wishes to broadcast a common message to a large number of receivers in a slowly fading wireless environment. We exploit cooperation between the receivers but impose an average sum power constraint across the network. As the number of receivers K → ∞, there is a critical rate C for the common message such that the outage probability of every receiver appr...

Cooperative communication is a vital area of research in wireless sensor networks due to its advantages for spatial diversity. Specifically, selective single relay cooperative communication is an area of vast research interest due to its simplicity and practicality. In this paper, we propose a selective single relay cooperative communication scheme for wireless sensor networks which adapts powe...

Cognitive radios (CR) and cooperative communications represent new paradigms that both can effectively improve the spectrum efficiency of future wireless networks. In this paper, we investigate the problem of cooperative relay in CR networks for further enhanced network performance. We investigate how to effectively integrate these two advanced wireless communications technologies. In particula...

Introduction: Cooperative communications [1] create diversity gains for network users with a single antenna. The classical cooperative scheme consists of two orthogonal time slots (TS): a broadcasting TS for a source (S) to transmit its signal to the intended destination (D), and a relaying TS for a relay (R) to retransmit S’s signal to D. There are amplify-and-forward (AF) and decode-and-forwa...

Cooperative diversity protocols are designed with the assumption that terminals always help each other in a socially efficient manner. This assumption may not be valid in commercial wireless networks where terminals may misbehave for selfish or malicious intentions. The presence of misbehaving terminals creates a social-dilemma where terminals exhibit uncertainty about the cooperative behavior ...

Next-generation wireless networks will go beyond the point-to-point or point-to-multipoint paradigms of classical cellular networks. They will be based on complex interactions, where the involved nodes cooperate with one another in order to improve the performance of their own communication and that of the global network. Cooperative communications based on relaying nodes have emerged as a prom...