Resource Scheduling Design In Data And Energy Integrated Networks

Nowadays,wireless mobile communication rises rapidly with a large number of devices flooding into wireless networks.In order to maintain the stable working of the network,ensuring the energy supply of these devices has become a key challenge to achieve the Internet of Everything.Based on wireless power transfer(WPT)and simultaneous wireless information and power transfer(SWIPT)techniques,micro/small communication devices equipped with rectifiers are able to convert radio frequency(RF)signals into direct current,which powers their operations for achieving energy self-sustaining of wireless networks.The resultant data and energy integrated networks(DEINs)supply us the main solution to tackle the energy shortage problem.However,WPT signals would occupy a part of network resources while providing energy.It results in the resource scheduling towards conventional wireless communication networks not being applicable to DEINs.Therefore,it has necessity to design dedicated resource allocation strategy for satisfying the dual requirements,i.e.,energy and information,so as to guarantee the high-performance.Currently,numerous researchers in the relevant field are dedicated to the various performance enhancement of DEINs.However,several pressing issues remain to be addressed.1)Energy of signals emitted by electrical devices rely on WPT signals harvesting.Hence,the remote devices suffer from more serious double path-loss.Nevertheless,current efforts generally overlook the dual far-near effect imposed by it,thus failing to ensure quality of service for the devices in DEINs.2)Existing works generally adopt block fading channel model.Due to the dynamic nature of real channel conditions,the model necessitates frequent pilot interactions? otherwise,outdated resource allocation may occur,leading to throughput performance decline.3)Time-sensitive applications for DEINs require timely information to reflect real states of environments or objects.However,major of current efforts pour into throughput and energy efficiency,etc,while information timeliness requirements in such applications are neglected.4)Fusion information,as one of the essential information types in time-sensitive scenarios,is essential for system decision-making.However,it lacks a precise metric for measuring its freshness.Therefore,freshness of the fusion information based decision cannot be guaranteed.In light of the above dilemmas,the dissertation specifically investigates the following four aspects:In the first part,a classical wireless powered communication network(WPCN)in DEINs is considered.In order to guarantee the quality of service of all user equipments in the network,a multi-domain resource allocation algorithm is designed.The WPCN is composed of a single hybrid access point(H-AP)and multiple user equipments.The former simultaneously carries out downlink wireless power transfer(WPT)and uplink wireless information reception,while the latter acquires energy from downlink RF signals emitted by the H-AP for powering their own information uploading.By considering the intense selfinterference(SI)at the H-AP,its adverse impact is attenuated through the spatial-domain design.In order to overcome the double far-near effect,the uplink fair-throughput within a single transmission frame is maximised.Specifically,a joint design is proposed,where the transmit beamforming and receive combining at the H-AP in the spatial-domain,the time allocation in the time-domain and the users’ scheduling in the user-domain are optimised.The numerical results demonstrate that the proposed multi-domain joint design achieves fast convergence and perfect fairness,while efficiently improving the uplink fairthroughput.In the second part,in order to enlarge the communication coverage of central infrastructures,a cooperative communication end-to-end network equipped with SWIPT aided relays is considered,where an end-to-end throughput enhancement strategy within consecutive transmission frames is studied then.The relays harvest the downlink RF signal transmitted by a source node,while these energies are subsequently consumed for powering information decoding and relaying.In order to store more sufficient energy and efficiently exploit them,an energy harvesting based selective-decode-and-forward protocol is proposed.Moreover,for alleviating the overhead induced by frequent pilot interactions,channel aging effect(CAE)is considered for formulating channels in the fact of the interframe channel correlation.A joint design is then proposed that transmit beamforming at the source node and relay selection as well as the transmit power and power splitting allocation are optimised for improving the end-to-end throughput within consecutive multiple frames.Simulation results demonstrate the performance superiority of the proposed design and illustrate the throughput gain by taking the impact of CAE into consideration.In the third part,in order to satisfy timeliness requirements arising from a large number of time-sensitive applications in DEINs,age of information(AoI)is analysed and optimised in a wireless powered relay aided end-to-end system.The relay powered by an H-AP receives information updates from a sensing equipment and then forwards to the HAP.Specifically,long-term AoI performances are analysed when the relay adopts either a decode and forward(DF)or an amplify and forward(AF)protocols,respectively.Moreover,the energy consumption for information decoding at the relay operating in DF is also discussed.In order to reduce computation complexity of closed-form AoI,an error control based Taylor approximation algorithm is proposed.The transmit power of the relay is further optimised for minimising the metric.Numerical results demonstrate the accuracy of the analytical solution and the great approximation effect of the proposed algorithm.Moreover,the appropriate scenarios for the two forwarding protocols are also obtained.DF is adopted for the scenario with sufficient energy supply while AF is suitable for that with lenient requirement for channel environment.In the fourth part,freshness of fusion information in multiple sensing devices aided DEINs is studied.Since the traditional AoI metric cannot measure freshness of fusion information integrating multiple information flows,a novel metric is proposed,namely age of sensing(Ao S).Specifically,batteryless sensing equipments cooperatively sense a common object in a WPCN,while the sensing information is then uploaded to a fusion center(FC)which decodes and fuses these information from different equipments.By considering that the sensing equipments may make error when they collect information,this study would further explore the reliability of the fusion information.Based on Ao S quantification,the WPT duration in the time-domain as well as the number and the position of devices in the deployment-domain is jointly designed.In particular,a Fibonacci aided integer programming is proposed for optimally tackling the formulated non-linear integer problems,which ultimately achieves the minimisation of average AoI.Simulation results show the accuracy of the theoretical analysis for Ao S and the great performance of the proposed algorithm.