Research On Energy Efficient Dynamic Spectrum Access Strategy For Cognitive Radio

With the develop ment of wireless co mmunication, a wire less spectrumresource has become the indispensable and precious resources in wire lesscommunication system. In recent years, the wire less communicatio n servicedema nd growth spurt, which make the scarce wire less spectrum resourcesbecome more nervous. The traditional static spectrum allocatio n means whatcause low utilizatio n ratio of the frequency spectrum and the imba lance of thespectrum, aggravate scarcity problem the wire less spectrum resources, restrictthe deve lopment of communication techno logy. And cognitive radio (CR) is thehot spot the next generation of wire less communication r esearch, use dynamicspectrum access server as the key techniq ues, the spectrum perception, spectrumsharing, spectrum ma nage ment and spectrum mobility of the CR obvious lyshowed its outstand ing advantage.In cognitive radio, dyna mic spectrum access techno logy is the coretechnology. Dyna mic spectrum access has obvious advanta ges in spectrumutilization re lative to the traditiona l static spectrum access. Dynamic spectrumaccess techno logy find the idle band in the syste m by spectrum sens ing, thecognitive user access an idle frequency band adaptive for communication, Inorder to achieve allocate the spectrum resources fle xibility. In the process o fpaper mainly research the energy effic iency o f dyna mic spectrum access,cognitive user use spectrum sens ing to obtain the status infor matio n of thechanne l at any time, and access to the channe l that the primary user is not usingthe opportunity. The trans miss ion and sens ing of the cognitive users both need toconsume a certain a mount of the energy of the system. In the ideal case, in orderto get more opportunities for spectrum access, cognitive user requires continuousperception wireless spectrum, that makes a serious waste of energy s ystems, sothe continuing perceived leading to premature consumption of the limited energysystem best. This shows that, energy issues in cognitive networks more researchsignificance compared to the traditiona l networks.Despite the continuo us perception of cognitive users can get more spectrumaccess opportunities, it is based on the expense of the s ystem at the expense ofenergy. When the perception in a large frequenc y, the cognitive users can getmore spectrum access opportunities. On the contrary, if the perception in a lowfrequency, it can save part of the system energy, but the cognitive users will misssome id le spectrum access opportunities. In order to improve the energyeffic ienc y of the cognitive network under the premise of ensur ing the primary user’s QoS, this paper designs energy effic ient cognitive radio dynamic spectrumaccess strategy, whic h introduced wait mechanis m, the cognitive users waiting toconsumption energy consumption is far less than the percep tio n of theconsumption of energy, Cognitive user access to the primary channe lopportunistic, it will make a collis ion with the pr imary user. When the number ofcollis ions is larger, it will serious ly affect the communication quality of theprimary user. This artic le will research how to improve the system energyeffic ienc y and to guarantee the norma l trans miss ion of the pr imary users toconduct in-depth, the collis ion probability of two users will set the limits that theprimary user is able to withstand, to study cognitive radio dyna mic energyeffic ienc y in the process of the spectrum access proble m.This artic le focuses on the fo llowing contents: Introduction the dyna micspectrum access based on continuous-time Markov cha in as well as the gradientoptimization a lgor ithm based on perturbation ana lys is in stochastic dynamicsystems. Design energy effic ie nt cognitive radio dyna mic spectrum access policyThen us ing the perturbatio n ana lys is theory in stochastic dyna mic systemsapplied to cognitive radio networks. Finally, based on the basic theory ofperturbation ana lysis, use the perturbation analys is gradie nt algorithm to ensurethat the primary user and cognitive user co llisio n probability within a set range,make the cognitive users average wait as the policy parameters to identifymaximize energy effic iency optima l strategy in energy effic ient cognitive radionetwork system, and ana lys is the trade-off between the energy effic iency and thecollis ion probability between primary users and cognitive users.