On The Energy Efficiency Of Wireless Cooperative Communication System

Wireless cooperative communication can expand the coverage area of the networks and improve the quality of network service and the system robustness,which can widely recognized as one of the key technologies of mobile communication networks in the future.The booming development of information and communication industry has led to a rapid growth trend of the energy consumption.This not only exacerbates the lack of energy resources,but also directly leads to the increase of operating costs for network providers.From both economic efficiency and sustainable development advantages,it is unavoidably important to reduce the energy consumption and improve the energy efficiency of the system while satisfying the traffic demand of users in the wireless networks.In the paper,the issues of energy saving in cooperative communication networks have been studied from the perspectives of “reduce expenditure” and “increase income”.This paper firstly models the wireless cooperative multi-path relay communication system,where one data source communicates with the intended destination with the assistance of decode-and-forward relays.In this paper,a joint self-adaptive power control and optimal relay route selection scheme is proposed to optimize the energy efficiency of the cooperative communication system while ensuring the quality of data transmission.With the proposed joint self-adaptive power control and optimal relay route selection scheme,the energy efficiency and outage probability of the cooperative network are analyzed and compared with other benchmark cases.Simulation results demonstrate a trade-off between the outage performance and energy efficiency of the system.Under the same outage performance,the system energy efficiency can be significantly improved with the proposed joint self-adaptive power control and optimal relay route selection scheme.In addition to advanced resource management and relay selection schemes,energy harvesting has become another way to reduce the energy consumption and improve energy efficiency of wireless cooperative systems.In order to improve the energy efficiency of cooperative system,simultaneous wireless information and power transfer(SWIPT)technology and energy harvesting technology are used in the cooperative communication system.WIPT cooperative multi-path relay network is studied,where energy-constrained relay nodes harvest energy from received source signal and use the harvested energy for forwarding the source signal to the destination.In order to collect more energy and ensure the reliability of signal transmission,with the channel state information each relay node dynamically selects a suitable power-splitting factor for signal decoding and forwarding,respectively.Depending on the channel state information available at the relays,different opportunistic energy harvesting and relay selection schemes are proposed.Simulation results demonstrate that a better outage performance can be achieved with more CSI available,while each relay node can harvest more energy.