The problem of jointly optimizing the source precoder, relay transceiver, and destination equalizer has been considered in this paper for a multiple-input-multiple-output (MIMO) amplify-and-forward (AF) relay channel, where the channel estimates of all links are assumed to be imperfect. The considered joint optimization problem is nonconvex and does not offer closed-form solutions. However, it ...

In this paper, we consider a two-way multiple input multiple output (MIMO) Amplify-and-Forward (AF) relay system, where interference is observed at the relay node during the multiple access (MAC) phase. For such a scenario, two new joint source-relay precoding algorithms with interference suppression are proposed and their performance analyzed through simulation results. These linear minimum me...

In this paper, Hybrid relay systems are comprised of Amplify-andForward (AF), Decode-and-Forward (DF) and DeModulate-and-Forward (DMF) together in cooperative networks. We propose adaptive relay schemes based on Channel State Information (CSI) of the received Signal-to-Noise Ratio (SNR) at the Relay Node (RN). We select the relay protocol adaptively, on the basis of Power Allocation (PA) constr...

In this article, we propose multiple-relay selection schemes for multiple source nodes in amplify-and-forward wireless relay networks based on the sum capacity maximization criterion. Both optimal and sub-optimal relay selection criteria are discussed, considering that sub-optimal approaches demonstrate advantages in reduced computational complexity. Using semi-definite programming convex optim...

This paper considers a wireless energy harvesting two-way relay (TWR) network where the relay has energy-harvesting abilities and the effects of practical hardware impairments are taken into consideration. In particular, power splitting (PS) receiver is adopted at relay to harvests the power it needs for relaying the information between the source nodes from the signals transmitted by the sourc...

In this paper, we propose an adaptive amplify-and-forward (AF) relaying scheme that selects the best relay among the available relay nodes opportunistically to cooperate with a source node for improvement of the spectral efficiency. This improvement can be achieved by introducing a policy that gives the useful cooperative regions and defines a switching threshold signal-to-noise ratio that guar...

This current paper addresses the noncooperative distributed wireless relay networks under a jamming environment. The amplifyand-forward single-input multiple-output (SIMO) and multiple-input single-output (MISO) schemes are considered with multiple N-relay nodes. The main contribution of this paper is to determine the optimal relay precoder vectors by minimizing the minimum mean square error (M...