This paper focuses on the optimal relay selection and power allocation issue, which studies the communication between SS (Secondary Source) and two SDs (Secondary Destinations) through single relay in CR (cooperative cognitive communication) system. Sufficiently takes the multi-antenna relay, primary-secondary users coexisting, and AF (Amplify and Forward) relay mode as the researching backgrou...

In this paper, we investigate a two-way relay network consisting of two sources, multiple cooperative relays and an eavesdropper. To enhance secure communications, a new relay chatting based on transmission scheme is proposed. Specifically, the proposed scheme selects a best relay that maximize the sum mutual information among the sources to forward the sources’ signals using an amplify-and-for...

We consider a two-way half-duplex relaying system where multiple pairs of single antenna users exchange information assisted by a multi-antenna relay. Taking into account the practical constraint of imperfect channel estimation, we study the achievable sum spectral efficiency of the amplify-and-forward (AF) and decode-and-forward (DF) protocols, assuming that the relay employs simple maximum ra...

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...

This paper addresses the issues in Underlay Cognitive Radio Networks employing amplify-and-forward relaying. The secondary users operating in an underlay mode in the frequency band of primary users must satisfy interference constraints to keep primary communication undisturbed. We propose a solution to this problem using cognitive relays and perform channel state information (CSI) based relay s...

This paper proposes single antenna relay system using Denoise and forward (DNF) scheme for MIMO transmission. In this scheme, the relay node eliminates the noise by identifying constellation, and retransmits after amplification. DNF does not amplify the noise, and the channel information is unnecessary in the transmitting side. In this paper, we propose the de-noising scheme for MIMO applicatio...