Research On Performance In Cognitive Radio Ad Hoc Networks With Underlay Spectrum Sharing Mode

Cognitive radio technology is an effective way to solve this contradiction spectrum resource shortages and underutilized spectrum,it is an intelligent wireless communication technology,which allows an unauthorized user does not affect the dynamic use of authorized users to work under the premise of the spectrum to achieve efficient use of spectrum.Cognitive Wireless Ad Hoc Networks(Cognitive Radio Ad Hoc Networks)combines the advantages of cognitive radio technology and Ad Hoc networks,not only dynamic use of the spectrum,but also with self-organizing Ad Hoc network flexibility.For cognitive wireless Ad Hoc network performance analysis,we must take into account the distributed multi-hop network architecture,dynamic network topology,and change with time and location of the available spectrum information and so on.Reasonable and effective performance metrics is critical for improving network performance.Transmission capacity is a concept used in wireless Ad Hoc network capacity issues raised in recent years,this concept very well make up for the lack of classical information theory in wireless network capacity decentralized analysis.Based in transmission capacity,the random network model for the modeling of wireless networks to provide a more practical and applicable models and stochastic geometry theory was random interference analysis model provides a set of powerful mathematical tool.In this paper,based on wireless Ad Hoc network performance measure existing research results,the use of random geometric theory of cognitive wireless Ad Hoc network modeling,study its capacity and latency.Specific work and results are as follows:It analyzes the wireless Ad Hoc network based on cognitive Underlay spectrum sharing mode.The capacity and delay.When the primary and secondary networks are modeled as independent Poisson point process and secondary network Underlay way with the main network shared spectrum use,secondary network by limiting its node density to meet the main constraints to achieve a network outage dynamic spectrum access.Analysis of the expected density in the reference transmission schedule jointly determined distance and direction angle outside the selected area recently receiving node under the policy(Expected Density of Progress).Product here expect progress within the network density per unit area is defined as the completion of a successful hop node number and the effective transmission distance.In this paper,the desired density goal progress were discussed with reference to the transmission distance and the transmission probability of individually optimized to derive the upper and send the best probability of individually optimized reference transmission distance of expression.The results given in closed local wireless Ad Hoc network delay and end delay of Cognitive Underlay spectrum sharing situation.Numerical and simulation results show that in the second network node density allowable range reference memory at an optimal distance,such that the desired progress density.