基于不同分组层策略的认知无线电网络性能分析

文中根据次用户采用的不同分组层策略，提出了两种认知无线电网络模型及其性能分析方法，推导了次用户的丢包率、分组时延、吞吐量以及频谱利用率表达式。同时，为了验证理论分析模型的准确性，对认知无线电网络的性能进行了仿真。分析和仿真结果表明：（1） 分析模型能准确地评估认知无线电网络的性能；（2）次用户的丢包率、分组时延和频谱利用率随着业务流入速率的增加而增加；（3）使用认知无线电技术，能大大提高频谱利用率；（4）次用户采用不同的分组层策略对频谱利用率的影响很小，但对吞吐量的影响很大。

Performance of Cognitive Radio Networks with Different Packet Level Policies

This paper mainly analyzes the performance of the cognitive radio networks with different packet level policies for secondary users. Here, two cognitive radio network models are proposed to derive the formulas for packet loss ratio, packet delay, spectrum utilization and throughput. Moreover, in order to evaluate the accuracy of the proposed analysis models, the paper performs simulations for the cognitive radio networks. The major observations include (1) the proposed analytical models can be used to accurately evaluate the performance of the cognitive radio networks; (2) the packet loss ratio, packet delay and spectrum utilization increase with the increase of the arrival rates for primary users and secondary users; (3) in a cognitive radio network, the spectrum utilization is much better than that in a traditional network; (4) adopting different policies for the packets do not make much difference to the spectrum utilization, but has a large effect on the throughput.