Consider an unstable linear time invariant system in which the sensor transmits information to a controller across an additive white Gaussian noise channel. The designer can optionally utilize a relay node to assist the controller; however the total transmission power consumed by the sensor and the relay node is constant. We consider two topologies: (i) a Gaussian relay channel, and (ii) a casc...

We proposed a new physical layer technique that can enhance the security of cooperative relay communications. The proposed approach modifies the decoded message at the relay according to the unique channel state between the relay and the destination such that the destination can utilize the modified message to its advantage while the eavesdropper cannot. We present a practical method for secure...

In modern transmission networks, relay plays an important role for cooperative strategies. Several relaying strategies, such as decode-forward, compress-forward and amplify-forward, have been proposed for relay channels and networks. However, the capacity for the general relay channel and network is still unknown. In this thesis, we propose several relay schemes for different relay models. In t...

Zero-error communication over a primitive relay channel is for the first time proposed and studied. This model is used to highlight how one may exploit the channel structure to design a relaying strategy that explicitly provides “what destination needs”. We propose the Colour-and-Forward relaying scheme which constructs a graph GR of relay outputs based on the joint conditional distribution of ...

This work concerns minimizing the achievable distortion of a Gaussian source over a two-hop block fading channel under mean square-error criterion. It is assumed that there is not a direct link between transmission ends and the communication is carried out through the use of a relay, employing the Decode and Forward (DF) strategy. Moreover, for both of transmitter-to-relay and relay-to-destinat...

We consider a state-dependent three-terminal full-duplex relay channel with the channel states noncausally available at only the source, that is, neither at the relay nor at the destination. This model has application to cooperation over certain wireless channels with asymmetric cognition capabilities and cognitive interference relay channels. We establish lower bounds on the channel capacity f...

In this paper we adapt and evaluate the performance of two classical pilotaided channel estimation schemes designed for OFDM systems: least square and minimum mean square error, in a relay-assisted scenario. We consider the Amplifyand-Forward, which is the simplest relay protocol for cooperative systems. Also, we consider the use of a single antenna at all the terminals: base station, user term...

A novel coding technique is proposed for the relay channel. The source broadcasts a recursive convolutional code to both relay and destination. After detecting the data broadcasted by the source, the relay interleaves and re-encodes the message prior to forwarding it to the destination. Because the destination receives both codes in parallel, a distributed turbo code is embedded in the relay ch...

A novel coding technique, termed distributed turbo coding, is proposed for the quasi-static relay channel. The source broadcasts a recursive code to both relay and destination. After detecting the data broadcasted by the source, the relay interleaves and re-encodes the message prior to forwarding it to the destination. Because the destination receives both codes in parallel, a distributed turbo...