The Spectrum Allocation Based On The Spectrum Aggregation Technology In Cognitive Radio

The utilization of spectrum has been more frequent as the radio communicationtechnology develops. But the lack of wireless spectrum has hampered thedevelopment of wireless communication services. It has been considered thatCognitive Radio (CR) technology is the best scheme to solve the problem of the lowusage of wireless spectrum. This paper mainly researches spectrum allocationalgorithm, key technology of cognitive radio. The technology which uses networkresources effectively and increases the system capacity according to the wirelessenvironment of CR plays a vital role in cognitive radio system performance.This paper analyzed the research projects’ background, and introduces thetarget and meaning of research briefly. The research status of cognitive radio anddynamic spectrum allocation algorithm are discussed in detail. Secondly, sometechnologies about CR are introduced. Include the introduction of CR and the fieldwhere CR used, some theories and pivotal technologies are drawn into theintroduction about CR.Then come of the first innovate core of this paper. And it is the static statespectrum allocation algorithm of spectrum aggregation technology in the CR. Theresearch contains three objectives and they are the numbers of user of CR, spectrumutilization and considering the user of CR and the spectrum utilization coalition.The core innovation of the static state spectrum allocation algorithm ismaximize the combinatorial numbers of the spectrum fragments and pick the best fitCR to get in the spectrum. The algorithm took the combinatorial numbers of thespectrum fragments and the best fit CR into account at the same time to optimize theoptimization objective.The another innovate core of the paper is introduce the spectrum poolingsystem to the algorithm of the dynamic spectrum allocation under the background ofthe NC-OFDM system. Also the algorithm is about the application of the spectrumallocation. The purpose of the introduction of the spectrum pooling system is t osolve the problems of how to improve the spectrum utilization、how to reduce thetime the CR get into the spectrum and how to reduce the number of spectrum switch.The spectrum allocation of the spectrum pooling system is set up multiple-stepspectrum pool. And the paper made a priority rank of the spectrum pool. In thespectrum pooling system the PU (primary user) and the SU have a different accessway to solve the problems mentioned. And the stimulations support the research.At the end of the paper a conclusion and a expectation are given.