This paper concerns two-hop communication over relay-assisted Block fading channel. It is assumed there is not a direct link between the transmitter and the affiliated destination and the communication occurs in two hops through the use of a relay, where the amplify and forward (AF) strategy is employed at this node. In this case, in a Rayleigh block fading channel, the optimal weight function ...

From practical and theoretical viewpoints, performance analysis of communication systems by using information-theoretic results is important. In this paper, based on our previous work on Multiple Access Channel (MAC) and Multiple Access Relay Channel (MARC), we analyze the impact of a relay on the fundamental wireless communications concept, i.e., coverage region of MARC, as a basic model for u...

In this channel,we study rate region of a Gaussian two-way diamond channel which operates in half-duplex mode. In this channel, two transceiver (TR) nodes exchange their messages with the help of two relay nodes. We consider a special case of the Gaussian two-way diamond channels which is called Compute-and-Forward Multiple Access Channel (CF-MAC). In the CF-MAC, the TR nodes transmit their mes...

abstract—in this paper, the problem of secure transmission in two-hop amplify-and-forward (af) systems with an untrusted relay is investigated. to prevent the untrusted relay from intercepting the source message and to achieve positive secrecy rate, the destination-based cooperative jamming (dbcj) technique is used. in this method the destination sends an intended jamming signal to the relay. t...

in order to evaluate the effect of nitrogen absorption and use efficiency in relay intercropping for winter wheat and maize, a field experiment was conducted during 2008-2009 at the agricultural research station of ferdowsi university of mashhad, iran. a randomized block design with three replications was used. treatments included four combinations of relay intercropping of wheat and maize (thr...

This paper presents a novel impedance-based approach for out-of-step (OOS) protection of a synchronous generator. The most popular and commonly used approaches for detecting OOS conditions are based on the measurement of positive sequence impedance at relay location. However, FACTS devices change the measured impedance value and thus disrupt the performance of impedance-based relay function. In...

Polar codes, that have been recently introduced by Arikan, are one of the first codes that achieved the capacity for vast numerous channels and they also have low complexity in symmetric memoryless channels. Polar codes are constructed based on a phenomenon called channel polarization. This paper discusses relay channel polarization in order to achieve the capacity and show that if inputs of tw...

in this paper, an interval approach is presented to achieve perfect selectivity and maximum sensitivity in distance relay zones, considering uncertainties. for this purpose, first, the uncertainties affecting the settings of the three zones of a distance relay are discussed. then, by using the monte-carlo simulation, the uncertainties are modelled and the impedances seen by the distance relay a...

Abstract—In this paper, the problem of secure transmission in two-hop amplify-and-forward (AF) systems with an untrusted relay is investigated. To prevent the untrusted relay from intercepting the source message and to achieve positive secrecy rate, the destination-based cooperative jamming (DBCJ) technique is used. In this method the destination sends an intended jamming signal to the relay. T...

in this paper, design and application of a new digital protective relay based on fuzzy logicand value estimation to a radial power system protection was presented. a novel approach based onvalue estimation was investigated for the proposed fuzzy logic based protective relay. in addition to thetheoretical aspect of fuzzy logic, mathematical definition of value estimation, detection andmeasuremen...