# Wireless Energy Harvesting with Cooperative Relaying under the Best Relay Selection Scheme
## 2 Related Works
The major idea was to employ stochastic geometry in deriving the mean proportional fairness utility function (PFUF) with respect to the receiver threshold and the associated probability of the user. The relaxed PFUF exhibited a concave function for the receiver threshold and the associated probability of the user. The alternative optimization approach was also used in the proposed suboptimal algorithm. The numerical results confirmed the effectiveness of the suboptimal algorithm with less computational complexity than recent related schemes. In [22], indoor EH relaying was applied over Log-Normal fading channels, a single relay was assumed. The performance of wireless transfer of the power for two-hop cooperative networks was investigated within indoor channels that have the log-normal fading distribution. Particularly, the authors considered two EH protocols, which are the PS scheme and TS scheme. They obtained precise analytical expressions for the ergodic outage probability and ergodic capacity for the previously mentioned protocols. The results illustrated that superior ergodic capacity is obtained when the channel variance is increased. The authors of [23] stated that CR is a promising technique that enhances the EE of cellular networks. However, the saved energy via deployed relays may be canceled by the static power consumption of the relay. EH is one of the techniques used for relays within cellular networks for flexible deployment and energy charge reduction. Cognitive radio was proposed to encourage the utilization of the spectrum via exploiting the existence holes of spectrum opportunistically. The authors of [24] considered the CR among secondary users to enhance the diversity of the spectrum. A spectrum-rich user node is chosen as the relay node to enhance the performance among the destination and the source. Cooperative communication was proposed to achieve better performance for the wireless network compared to traditional wireless networks. A great deal of attention and importance has been given to these networks since they can be used in different types of networks and applications, such as: military, cellular and ad-hoc/sensor networks. In [25], the OP behavior was investigated for a cooperative network over a wireless channel with a Nakagami-m fading type. The authors derived a closed-form expression for the OP. The authors of [26] analyzed threshold-based selection combining (SC) and threshold-based maximal ratio combining (MRC) the signals of these multiple antenna Nakagami fading channels. They discovered that the end-to-end (E2E) network error performance with few number of relays and many antennas is not considerably worse compared to that who own many relays everyone has a less number of antennas. In [27], precise ergodic capacity for different adaptive protocols in DF system under different Rician fading channels was studied for optimal rate adaptation with constant power, optimal rate adaptation and simultaneous power, channel inversion based fixed rate. Through capacity analytical expressions, the optimal rate adaption and power offers superior capacity compared to optimal rate adaption by means of constant power over different Rician channels from low to reasonable SNR. In [28], spectrum sensing for cognitive radio scenarios was proposed, and the communication frame classified based on the orthogonality and the ability of th ecooperative channel. In order to do thiy, four protocols were investigated: multiple access channel (MAC), parallel access channel (PAC), cooperative MAC (CMAC) and cooperative PAC (CPAC). Channel-aware binary-decision fusion over a shared Rayleigh flat-fading channel with multiple antennas at the Decision Fusion Center (DFC) was proposed in [29]. Two approaches were presented, Decode-and-Fuse (DaF) and Decode-then-Fuse (DfF). Authors in [30] proposed an analysis of large-array regime at the DFC. To reduce the complexity, the authors derived Sub-optimal fusion rules. The authors of [31] presented two schemes for the cooperation.