Power‐Splitting Scheme for Nonlinear Energy Harvesting AF Relaying with Direct Link

Abstract

Simultaneous wireless information and power transfer (SWIPT) is a promising technique to prolong the lifetime of energy-constrained relay systems. Most previous works optimize power-splitting (PS) scheme based on a linear or a simple two-piecewise linear energy harvesting (EH) model, while the employed EH model may not characterize the properties of practical EH harvesters well. This leads to a mismatch between the existing PS scheme and the practical EH harvester available for relay systems. Motivated by this, this paper is devoted to the design of PS scheme in a nonlinear EH amplify-and-forward energy-constrained relay system in the presence of a direct link between the source and the destination. In particular, we formulate an optimization problem to maximize the system capacity according to the instantaneous channel state information, subject to a nonlinear EH model based on the logistic function. The objective function of the formulated problem is proven to be unimodal and there is no closed-form expression for the optimal PS ratio due to the complexity of logistic function. In order to reduce overhead cost of optimizing PS ratio, a simpler nonlinear EH model based on the inverse proportional function is employed to replace the nonlinear EH model based on the logistic function and we further derive the closed-form expression for the optimal PS ratio. Simulation results reveal that a higher system capacity can be achieved when the PS scheme is optimized based on nonlinear EH models instead of the linear EH model, and that there is only a marginal difference between the capacity under the two optimal PS schemes optimized for two different nonlinear EH models.

Optimization of Full-Duplex Relaying System With Non-Linear Energy Harvester

“…The developed non-linear EH models are being used in the design and analysis of various SWIPT systems [27]- [33], [35]- [39], [42], [45]. For the non-linear EH model relaybased systems specifically, based on the sigmoid function [24], [32] study the PS scheme for the HD-AF relay-based system in the presence of a direct link between source and destination, where as [33] studies the resource allocation and relay selection in a two-hop AF relay-assisted HD multi-user orthogonal frequency division multiple access (OFDMA) network with PS scheme. Based on LC model, [35] calculates the outage capacity of the HD-AF relay system with TS protocol, whereas [36] deduces the expression of the secret outage probability in the HD multi-DF relay-based system with PS protocol.…”

Simultaneous Wireless Information and Power Transfer With Cooperative Relaying for Next-Generation Wireless Networks: A Review

“…They proved that lesser OP is expected in Nagakami instead of the Raleigh fading channel. In [109], Bai et al investigated PS scheme in nonlinear EH, AF relay network with a direct link. They formulated an optimization scheme for system capacity maximization according to instantaneous CSI based on nonlinear EH model considering a logistic function.…”

Performance Analysis of UAV Relay Assisted IoT Communication Network Enhanced With Energy Harvesting

“…Ji et al [17] explored PS schemes for nonlinear energy harvesting AF relay systems with direct path and optimized system to maximize system capacity. Bai et al [18] proposed a new hybrid EH protocol such as a combination of power splitting and time switching. In order to maximize the system throughput performance, Atapattu and Evans [19] analyzed the outage probability expression of a nonlinear energy harvesting and decoding system in the two-hop transmission relay network under the influence of interference through a multiple parameters joint optimization.…”