In this chapter, a cooperative broadband relay-based resource allocation technique is proposed for adaptive bit and power loading multiple-input-multiple-output/orthogonal frequency division multiplexing (MIMO-OFDM) system. In this technique, sub-channels allocation, M-QAM modulation order, and power distribution among different sub-channels in the relay-based MIMO-OFDM system are jointly optim...

IEEE 802.15.4 is a global standard designed for the low power consumption, low cost, and low data rate. Thus, this standard is advantageous to implement ubiquitous sensor network (USN). However, researchers do not have been studied to employ cooperative communication in this system. Cooperative relaying system has been shown to help the destination to get the spatial diversity. It is possible t...

This paper evaluates intercept probability (IP) of a cooperative cognitive radio network. Using Fountain codes, secondary source continuously generates encoded packets, and sends them to destination relay nodes that attempt receive sufficient number the pa

Cooperative networking schemes in wireless networks provide cooperative diversity gain using differently located antennas that combat fadings induced by multipath propagation. In this paper, we present the optimal weight design for the destination in AF (Amplify and Forward) relay system, where the optimally designed MRC (Maximum Ratio Combining) is employed at the destination for S→D link (dir...

The problem of jamming plays a very important role in ensuring the quality and security of wireless communications, especially now when wireless networks are quickly becoming ubiquitous. Since jamming phenomenon can be considered as a game where a player (say, jammer) is playing against a user (transmitter), game theory is an appropriate tool for dealing with the jamming problem. In this paper ...

In this paper, we propose joint cooperative beamforming and jamming schemes in decode-and-forward (DF) relay networks for physical layer secrecy. In DF relay networks, only the relays decoding the message from the source correctly have to join in the forwarding phase and the relays with decoding error are not utilized sufficiently. Taking this property into consideration, we let the relays deco...

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...

The cooperative relay channel is a recent model for the exploitation of the spatial channel. One user node relays information from the source to the destination which in turn improves the error rate performance due the multiple receive copies i.e. diversity gain. The foundation for any investigation of cooperative diversity channels is based on an accurate and reliable simulation environment. T...

Cooperative diversity uses relays which assist source destination transmissions to reduce link outage rates in multipath fading environments. In this paper, an Amplify-and-Forward (AAF) cooperative communication system over Nakagami-m fading channel is considered where a source node communicates with a destination node directly and indirectly (through multiple relays). Nakagami-m fading channel...

In this paper a new cooperative transmission scheme is proposed that enjoys some important advantages over similar protocols First it achieves cooperative diversity without relying on orthogonal subspaces e g di erent spreading codes or frequency bands allowing full rate transmission Second its performance degrades gracefully as the path loss between cooperating partners increases never falling...