Research On Spectrum Sensing And Resource Allocation In Cognitive Radio Networks

The existing static spectrum allocation scheme in wireless communication makes the spectrum utilization low and the cognitive radio is widely concerned because of its dynamic use of spectrum.Spectrum sensing and resource allocation are key techniques for cognitive radio,The former mainly detects the free band and allows the cognitive user to take the opportunity to access it.The latter is mainly to distribute the perceived free spectrum resources to the cognitive users.Firstly,this article introduces the utilization of spectrum opportunity in the beginning,which is an important index for cognitive user actual perception performance evaluation,and analysis several factors influencing the utilization ratio of spectrum space,proves the existence of the optimal time perception can maximize the utilization of spectrum opportunity.Under the transfer rate of 100 KBPS,packet 500 bits,0.9 false-alarm probability and detection probability under the condition of 0.9,etc,to calculate the optimal spectrum perception of time is about 2 ms.In addition,we also studied how to conduct multi-user collaborative spectrum sensing in a centralized cognitive radio network composed of a fusion center and N cognitive users.This paper proposes a greedy heterogeneous parallel channel multi-user collaborative spectrum sensing method to overcome the existing methods only consider the detection accuracy and ignores the perceived cost,system benefit and the different cognitive users on the properties of different heterogeneous channel perception differences and participate in collaborative perception of the cognitive users more problems.Finally,cooperative communication is an effective way to reduce the waste of spectrum resources,and it is also an alternative way to transmit transmission through relay.This paper proposes an optimized resource allocation algorithm to maximize the throughput of cognitive radio networks.A non-repeatable model is used if the maximum rate of transmission of the main user under this subchannel is greater than the target rate required to ensure the quality of the call.Instead,let one or more cognitive users communicate with the master user.The simulation results show that the resource allocation algorithm presented in this chapter is more efficient than the traditional cooperative relay resource allocation algorithm.