关键词: 动态频谱分配，频谱可用性，描述方法，可用时长，更新频率

Abstract: In the spectrum resources description of the dynamic spectrum allocation, we introduce two characteristic parameters to construct a spectrum description model. This method enrich description of the resource features. Because of differences in demand for spectrum, give the different weights of spectrum availability and the free probability respectively,so that the user is assigned an appropriate spectrum. Simulation results show that different types of business result different spectrum availability and the free probability parameters combined together to describe the spectrum availability, it can be appropriate to improve the spectrum efficiency. The spectrum efficiency can be increased by about 40% when the weight of free probability is much greater than the spectrum availability, especially for the voice signal.

Key words: Dynamic spectrum allocation, Spectrum availability, Description method, Availability time, Update frequency