We study the asymptotic behavior of a cooperative scheme operating in amplify-and-forward (AF) mode when the number of relay terminals tends to infinity. We consider three time-division-multiple-access-based cooperation protocols which realize different degrees of broadcasting and receive collision. Optimal design rules for distributed space–time codes (STCs) are derived through the investigati...

In this paper, our objective is maximizing total sum-rate subject to power constraints on total relay transmit power or individual relay powers, for amplify-and-forward single-antenna relay-based wireless communication networks. We derive a closed-form solution for the total power constraint optimization problem and show that the individual relay power constraints optimization problem is a quad...

In this paper, non-orthogonal multiple access (NOMA) in cooperative relay system is considered, where a source node communicates with pair of energy harvesting (EH) user equipments through antennas node. A hybrid protocol adopted at the relay, which if can successfully decode signals, decode-and-forward (DF) will be to forward signals users. Otherwise, amplify-and-forward (AF) implemented. Assu...

We motivate the study of a certain class of random Fibonacci sequences which we call continuous random Fibonacci sequences by demonstrating that their exponential growth rate can be used to establish capacity and power scaling laws for multihop cooperative amplify-and-forward (AF) relay networks. With these laws, we show that it is possible to construct multihop cooperative AF networks that sim...

An opportunistic relay selection based on instantaneous knowledge of channels is considered to increase security against eavesdroppers. The closed-form expressions are derived for the average secrecy rates and the outage probability when the cooperative networks use Decode-and-Forward (DF) or Amplifyand-Forward (AF) strategy. These techniques are demonstrated analytically and with simulation re...

In this paper we present the performance analysis of a novel channel assignment scheme where two non-cooperative independent users simultaneously communicate with their destination through a single relay by using only two frequency channels. The analytic derivation of the probability of symbol error for two main relay techniques will be provided, namely Amplify-and-Forward (AF) and Decode-and-F...

To minimize total transmit power in a system while guaranteeing the outage probability at the same time in a cooperative system, we propose and analyse two threshold-based hybrid relay selection and power allocation schemes for a threenode cooperative relaying system. They are designated as: the hybrid amplify-direct-forward relaying (HADF) and incremental hybrid decode-direct-forward relaying ...

In this study, we study compressive channel estimation for Orthogonal Frequency Division Multiplexing (OFDM) modulated Amplify-and-Forward (AF) relay networks. Based upon the mathematical channel model of P2P and sparseness measure function, by using Monte-Carlo runs, we show that the OFDM cooperation convoluted channels also exhibit sparsity. In this study, we propose two compressive channel e...

Resumo—Este artigo investiga o desempenho de outage de sistemas cooperativos amplifica-e-encaminha (AF) de dois saltos em um ambiente de desvanecimento Nakagami-m limitado por interferência. Mais especificamente, assumindo a presença de múltiplos interferentes Nakagami-m no relay AF e um terminal destino ruidoso, aproximações simples e em forma fechada para a probabilidade de outage fim-a-fim s...

In this paper, we consider single-source, single-sink (ss-ss) multi-hop relay networks, with slow-fading Rayleigh links and single-antenna relay nodes operating under the half-duplex constraint. We present protocols and codes to achieve the optimal diversity-multiplexing tradeoff (DMT) of two classes of networks. Networks belonging to the first class can be viewed as the union of K node-disjoin...