We analyze fading interference relay networks whereM single-antenna source-destination terminal pairs communicate concurrently and in the same frequency band through a set of K single-antenna relays using half-duplex two-hop relaying. The relays do not have channel state information, perform amplify-and-forward (AF) relaying, and the destination terminals can cooperate and perform joint decodin...

In this thesis, noncoherent cooperative amplify-and-forward (AF) half-duplex relay systems and wireless communication systems equipped with a single transmitter antenna and multiple receiver antennas (SIMO) are considered, in which perfect channel information is unavailable at the destination end. For the AF half-duplex relay systems, the use of the least square error (LSE) receiver is proposed...

New aspects arise when generalizing two-way relay network with one relay to two-way relay network with multiple relays. To study the essential features of the two-way multiple-relay network, we focus on the case of two relays in our work. The problem of how two terminals, equipped with multiple antennas, exchange messages with the help of two relays is studied. Five transmission strategies, nam...

In this treatise a two-way Amplify and Forward (AF) relay-aided system is considered, which employs the so-called Arithmetic Sum of Average Bit Error Rate (ASABER) based MIMO precoding technique. The two-way AF relay system is comprised of the pair of transceiver nodes S1 and S2, and the Relay Node (RN) R, where each node is equipped with N1, N2 and Nr antennas, respectively. We study the effec...

In this paper, both the security and the reliability performance of the cognitive amplify-and-forward (AF) relay system are analyzed in the presence of the channel estimation error. The security and the reliability performance are represented by the outage probability and the intercept probability, respectively. Instead of perfect channel state information (CSI) predominantly assumed in the lit...

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...

Satellite communications and relaying techniques have been receiving the attention of the research community over the last years. This paper proposes a terrestrial to satellite communication system aided by terrestrial relay nodes to facilitate a robust, reliable, and efficient communication link and improve the spectral efficiency. In particular, this paper concentrates on evaluating the spect...

Performance of multi-hop MIMO relay channels under the amplify-and-forward and decode-and-forward protocols are compared via the capacity and SNR gains. In an N hop channel of linear topology with multi-antenna source and destination and single-antenna relay nodes, the capacity gain of the DF relaying over the AF one does not exceed log2N bit/s/Hz and its SNR gain does not exceed N , for any ch...

future generations of cellular communications require higher data rates and more reliable transmission link .Cooperative communications have a great significant in modern communications as they improve the information transmission between the source and the destination by using the relays. The relaying schemes are Amplify-and-Forward (AF) in which the relay sends an amplified copy of its receiv...

Cooperative wireless communication has received significant attention during recent years due to several reasons. First, since the received power decreases rapidly with distance, the idea of multi-hopping is becoming of particular importance. In multi-hopped communication, the source exploits some intermediate nodes as relays. Then the source sends its message via those relays to the destinatio...