Abstract— In this paper, the Gaussian relay channel with linear time-invariant relay filtering is considered. Based on spectral theory for stationary processes, the maximum achievable rate of this subclass of Gaussian relay operation is obtained in finiteletter characterization. The maximum rate of this subclass can be achieved by dividing the overall frequency band (or the overall time interva...

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...

In this paper, we present the results from over-the-air experiments of a complete implementation of an amplify and forward cooperative communications system. Our custom OFDM-based physical layer uses a distributed version of the Alamouti block code, where the relay sends one branch of Alamouti encoded symbols. First we show analytically and experimentally that amplify and forward protocols are ...

In this paper, we present the results from over-the-air experiments of a complete implementation of an amplify and forward cooperative communications system. Our custom OFDM-based physical layer uses a distributed version of the Alamouti block code, where the relay sends one of the branches of Alamouti encoded symbols. First we show analytically and experimentally that amplify and forward proto...

In this paper, the impact of limited resources on achievable rates in relay channels is investigated. Resource limitation is modeled as a rate constraint, R, which constrains the rate at which a relay can reliably decode or source-code data. With this constraint in hand, the achievable rates for several protocols are derived and compared: decode-and-forward, estimate-and-forward, a Markovian am...

In this article, we develop an analytical framework for the performance analysis of cooperative amplify-and-forward (CAF) relay-based energy detection. We derive mathematical expression for the detection probability for single cognitive relay system and later extend it to multi-relay system. Our resulting expression is based on the canonical series representation of generalized Marcum Q-functio...

In this paper, we consider the joint problem of relay selection and optimal power allocation for multi-relay amplify-and-forward (AF) cooperative communication system over frequency selective fading channels. An optimization model combined relay selection and power allocation under a total transmission power budget is formulated. Then, this combinatorial problem is solved in a distributed strat...

In this paper, we investigate the secrecy outage probability (SOP) for the cooperative amplify-and-forward (AF) two-way relay networks (TWRN) with channel estimation (CE) errors under Rayleigh fading channels. In the proposed system, two sources simultaneously broadcast their respective information to all the relays firstly. Then, the optimal relay performs AF protocol on the received signals s...