Optimalallocation Of Cognitive Radio Network Resources Under Simultaneous Information And Power Transfer

Cognitive radio technology has a very broad development prospect in improving the utilization rate of wireless spectrum and improving the shortage of spectrum resources.Energy harvesting is a promising solution to extend the operation of energy constrained networks.The cognitive radio network adopts the radio frequency energy harvesting to build a new network mode,namely,the cognitive radio network with wireless power supply.In this network mode,the system design of the traditional cognitive radio network is improved.At the same time,the spectrum and energy efficiency solutions are provided for the wireless network,so that the activities of the main user are more easily detected by spectrum sensing,and it is easy to find the spectrum opportunities of information transmission or radio frequency energy harvesting.However,due to the introduction of energy harvesting,the network also faces some problems and challenges: how to deal with the balance between energy efficiency and rate;how to ensure the system to maintain good communication quality in a complex and diverse communication environment;how to develop energy harvesting methods.Aiming at the above problems,this paper discusses the wireless power supply cognitive wireless network under different energy harvesting modes.By designing power control algorithms,it guarantees user communication quality and service requirements,and achieves energy rate trade-offs and optimized system resource allocation.Firstly,the cognitive radio network under the mode of power splitting energy harvesting is studied,in which the secondary user receives the radio frequency signal of the secondary transmitter,obtains the energy harvesting and decoding information according to a certain ratio,considers the uncertain channel model of instantaneous state information,and puts forward the problem of the energy efficiency of the secondary system.By fractional programming and problem decomposition,the original problem is transformed into a convex optimization problem which is easy to deal with.An effective algorithm is designed to optimize the power and splitting ratio,improves network communication performance.Secondly,the optimization of the power and time allocation of cognitive radio networks under the time switching energy harvesting mode is studied.An inequality based on interrupt probability is used to describe the impact of channel uncertainty,and the constraint of interrupt probability is established.Based on the convex optimization theory,the optimal variables are solved,the algorithm of power and time switching allocation is given,and the convergence of the algorithm is proved to maximize the system energy efficiency.Finally,the cognitive radio network in the wireless power supply communication network mode is studied.Considering the energy causal constraints and interference power constraints,the optimal time and power allocation scheme is proposed.In the scenario of simultaneously achieving downlink energy collection and uplink information transmission,a secondary system throughput and maximization problem is established,and solved by convex optimization theory and Lambert function to obtain the optimal resource allocation scheme.