Abstract: Cooperative spectrum sensing can enhance the capabilities of spectrum sensing in cognitive radio, while different system parameters will produce different effects on the performance of cooperative spectrum sensing. After considering the system resource utilization and normalized throughput, the impact of the number of users and sensing duration under different conditions on system performance is analyzed. And under the condition of detection probability constraint, optimization of the system utility combined system detection probability and normalized throughput is proposed, which can be obtained to meet the conditions of the maximum system utility value. Simulation results show that in different environments and conditions, the number of users and the sensing duration needed to achieve the maximum system utility are different.

Key words: cognitive radio, cooperative spectrum sensing, system utility, optimization analysis, sensing duration

摘要： 协作频谱感知可以提升认知无线电的频谱感知能力，但不同的系统参数对协作频谱感知系统的性能会产生不同的影响。在综合考虑系统资源利用率和归一化吞吐量的情况下，对不同条件下用户数和感知时长对系统性能的影响进行分析。并在检测概率约束条件下，对结合系统检测概率和归一化吞吐量的系统效用提出优化方法，可以求出满足条件的最大系统效用值。仿真结果表明，在不同的环境和条件限制下，达到最大系统效用所需要的用户数和感知时长也是不同的。

关键词: 认知无线电, 协作频谱感知, 系统效用, 优化分析, 感知时长