Optimization Methods For Spectrum Sensing Estimation Delay Time In Cognitive Radio Networks

In the field of wireless communications,the contradiction between ever-increasing user demands and limited spectrum resources has become increasingly prominent.The limited spectrum resources will restrict the development of wireless communication technology.The introduction of cognitive radio technology puts forward new ideas for the utilization of spectrum resources and transforms the traditional static allocation of spectrum resources into dynamic spectrum resource allocation.The spectrum sensing technology in the cognitive radio is the most critical technology,in which the spectrum sensing delay time length will affect the system throughput.The too long spectrum sensing time will lead to the system throughput decreasing,otherwise the too short spectrum sensing time will affect the estimation accuracy of the spectrum channel sensing,and increase the interference to authorized users.Therefore,the optimization of spectrum sensing time is of great research value.This paper studies the optimization algorithm of spectrum sensing channel estimation delay in cognitive wireless networks.The main research work and results are as follows:(1)Systematically introduces the cognitive radio spectrum sensing and cognitive radio time-delay of spectrum sensing of the research status at home and abroad,and focuses on analyzing the concept of cognitive radio network,cognitive relay networks,spectrum sensing superiority,key technology and common methods of spectrum sensing delay optimization.(2)In order to optimize the time-delay of spectrum sensing channel estimation in cognitive wireless networks,the model of spectrum sensing delay optimization in OFDM-based cognitive wireless networks is analyzed.Aiming at maximizing the throughput of the system,the channel interference and channel power become the main constraints of the optimization model.A stochastic programming method is proposed to solve the optimization problem of spectrum sensing delay estimation model.Computer simulation results show that the algorithm is effective and has certain engineering application value.(3)Applying the cooperative relay in cognitive wireless network,the single-channel cognitive relay network with decoding and forwarding relay cooperation is discussed.The performance of spectrum sensing delay in single-channel cognitive radio network with relay is analyzed.A delay model of channel estimation for decoding and relaying cognitive relaying network is researched.An improved stochastic programming algorithm is proposed to derive and simplify the channel estimation delay model so as to obtain the convex function of the channel estimation delay of the decoding and forwarding cognitive relay network model.The optimal channel estimation delay isobtained through computer simulation,which can improve the system throughput.