中文摘要：

动态频谱接入技术允许非授权用户利用已授权分配频谱信道的空闲空隙完成数据传输，但是要求不能对授权用户的信道传输造成严重影响。在两种不同的频谱信道共享策略下，利用排队分析模型，对采用动态频谱接入技术的非授权用户的链路传输性能以及对授权用户的传输影响进行了分析，并讨论了非授权用户性能的优化。尽管增加可利用的授权频谱信道的数量可以改善非授权用户的传输性能，但是其传输吞吐量的增加只能趋近于一个上界值。

英文摘要：

Dynamic spectrum access technology aims at improving spectrum utilization by allowing so-called secondary users to transmit in already assigned primary users＇ bands, provided that no significant amount of interference was generated. Dynamic spectrum access radio devices looked for temporarily unoccupied frequency bands and attempted to communicate in them. This paper proposed two spectrum sharing schemes for dynamic spectrum access system, and both the impact on the primary user＇ s link performance and the transmission performance that could be acquired by the secondary user under the two spectrum sharing schemes were investigated using queueing system models. By optimizing the message length transmitted by the secondary user, it could improve the secondary user＇s goodput and enhance the channel utilization. However, the throughput achieved by the secondary user can only approximate to an upper bound even though muhiple channels are available for the secondary user to use.