Decode and forward relaying

In this paper, we study a cooperative cognitive radio network (CCRN) where the secondary user-transmitter (SU-Tx) assists bi-directional communication between a pair of primary users (PUs) following the principle of two-way relaying. In return, it gets access to the spectrum of the PUs to enable its own transmission to SU-receiver (SU-Rx). Further, in order to support sustainable operation of the network, SU-Tx is assumed to harvest energy from the RF signals received from the PUs, using the technique of simultaneous wireless information and power transfer (SWIPT). Assuming a decode-and-forward behaviour and power-splitting based relaying protocol at SU-Tx, closed form expressions for outage probability of PU and SU are obtained. Simulation results validate our analytical results and illustrate spectrum-efficiency and energy-efficiency advantages of the proposed system over one-way relaying. KEYWORDS Cooperative cognitive radio network, simultaneous wireless information and power transfer, two-way relaying, decode-andforward relaying.

We derive bounds on the error probability of optimal and sub-optimal detectors in an uncoded decode-andforward relay system with two correlated information sources. This setup is relevant to wireless sensor networks where nearby sensors collect spatially correlated data. We show that taking into account the source correlation at the relay and at the destination leads to significant performance gains. Simulation results corroborate the tightness of our analytical bounds.

In this paper, we study a cooperative cognitive radio network (CCRN) where the secondary user-transmitter (SU-Tx) assists bi-directional communication between a pair of primary users (PUs) following the principle of two-way relaying. In return, it gets access to the spectrum of the PUs to enable its own transmission to SU-receiver (SU-Rx). Further, in order to support sustainable operation of the network, SU-Tx is assumed to harvest energy from the RF signals received from the PUs, using the technique of simultaneous wireless information and power transfer (SWIPT). Assuming a decode-and-forward behaviour and power-splitting based relaying protocol at SU-Tx, closed form expressions for outage probability of PU and SU are obtained. Simulation results validate our analytical results and illustrate spectrum-efficiency and energy-efficiency advantages of the proposed system over one-way relaying. KEYWORDS Cooperative cognitive radio network, simultaneous wireless information and power transfer, two-way relaying, decode-andforward relaying.

In this paper, optimum transmission distances are obtained for different relay nodes in the serial and parallel decode-and-forward relaying schemes by using differential evolution algorithm in free-space optical communication systems. The transmission distances are investigated by optimizing the place of the relay nodes at a target outage probability of 10 −6. In this study, the numerical results reveal that the optimum transmission distances are increased for both the whole power margins and different number of relay nodes with the help of the proposed optimization technique.

A performance analysis of both centralized and decentralized cooperation diversity schemes involving decodeand-forward relay nodes is carried out in the case of Middleton Class A impulsive disturbance. It is shown that, with respect to the Gaussian noise case, the presence of impulsive disturbance does not significantly affect the performance of the maximumlikelihood detector in terms of coding gain and asymptotic diversity order. Instead, the major effect of the impulse disturbance is on the finite signal-to-noise ratio (SNR) diversity order, which does not monotonously increase as the SNR rises. Numerical results are provided to validate the derived theoretical results.