Research On Cooperative Resources Allocation Based On Cognitive Radio

The spectrum resources become increasingly scarce for the growing number of the wireless communication equipment.And the spectrum utilization rate of the fixed spectrum allocation system is relatively low.As a result,various techniques have been developed and utilized to solve the lack of spectrum resources and the low utilization rate problem.The cognitive radio is one of the techniques in this domain,recognized as one of the best ways to solve the spectrum problems.The cognitive radio enable the non-authorized cognitive users to communicate in the authorized spectrum communication network,so as to improve the spectrum utilization rate and ease the situation of shortage of spectrum resources.However,there are poor communication quality,low transmission rate and energy shortage problems in the practical cognitive radio networks,the cooperative relay technology can achieve a high-speed and reliable "green" communication,by using resource sharing and cooperation between the network nodes,which improves the performance of wireless communication.So,the integration of the cooperative relay and the cognitive communication network can effectively improve the communication quality of the users,increase the transmission opportunities of cognitive users and improve spectrum utilization rate.The main research of this paper is about the spectrum allocation,the power allocation and the energy harvesting time,by which solving the existing problems of the cognitive cooperative wireless communication network,as described below:(1)For the problem of low frequency spectrum utilization,power and spectrum optimization assignment algorithm of the cognitive cooperative relay network is proposed.Based on AF relay mode,the mathematical model of cognitive user transmitting efficiency is established,considering the limited cognitive user and primary user interference and other factors.And optimal power and spectrum allocation solutions are obtained by Lagrange?and traversal searching method.Finally,the simulation results show the superiority of the proposed strategy(2)For energy-constrained CR networks,the optimal allocation algorithm of power and energy harvesting time in cognitive cooperative relay networks is proposed.Based on DF relaying model,the optimization mathematical model of cognitive user SINR is established,considering energy constrain of the cognitive users and interference of the primary users and other factors and by.optimizing the allocation of energy harvesting time and power to optimize the SINR of cognitive user;At last,numerical results are provided to validate this analysis.