Multi-User Cooperative Spectrum Sensing Algorithm Based On HMM Model And Construction Of The Simulation System

With the coming of the information age and rapid development of mobile intelligent terminal,wireless spectrum resources have become one of the most valuable resources in modern society.In the current case of using unified allocation to use the radio spectrum,there are few bands available for allocation in other areas.In addition,these allocated spectrum utilization rates are not high,only 15%～85%,leading to a serious waste of spectrum resources.Therefore,how to improve the spectrum utilization has become one of the hot topics in the field of communication.Spectrum detection is the core technology of cognitive radio.Cognitive radio searches for the spectrum hole by detecting the spectrum state of the surrounding wireless communication environment,so that the cognitive radio system can adapt to the surrounding communication environment.(1)In this article raised introducing multiple secondary users to Cognitive radio network and carrying out HMM modeling to main users spectrum.Recursion calculating forecast probability of user’ s next time slot spectrum status is ’busy’ or ’leisure ’.And counting all secondary users ’busy’ and "leisure" frequency,if the percentage of ’busy’ exceeds a certain value,so could judge following time slot spectrum status is ’busy’,otherwise it is ’leisure’.The simulation results show that the algorithm is 20%higher than the average energy sensing algorithm,and it is more obvious at low level.This paper improves the perceived reliability while rapidly detecting the spectrum,and greatly reduces the interference to the primary user.(2)At present,there is no a special cognitive radio simulation platform,and our proposed simulation of multi-user cooperative spectrum sensing based on HMM(hidden Markov model)is best to simulate in the real cognitive radio simulation platform to verify the effect,which can measure the practicability and accuracy of this algorithm.Based on this problem,we design a NS-3 cognitive radio simulation platform and add different topologies and generators to simulate different communication environments,and verify the simulation results of multi-user cooperative spectrum sensing based on the HMM model in different wireless environments.