研究了协作通信与认知无线电的结合,针对TD-SCDMA系统和WiMAX系统组成的异构无线网络,提出了一种基于多用户分集的协作频谱感知机制。根据该算法,WiMAX用户被分成若干个簇,选择每个簇内瞬时信道条件最好的WiMAX用户协作检测频谱,并利用软硬结合的判决手段,既保证检测性能,又不增加复杂度。分析和仿真表明,该算法一方面保证了频谱检测的可靠性,降低了虚警概率,另一方面减少了通信开销,提高了判决消息传输的可靠性,达到了提升频谱利用率的目的。
In order to achieve spectrum sharing in the heterogeneous wireless environment consisting of TD-SCDMA system and WiMAX system, a robust cooperative spectrum sensing scheme based on multi-user diversity is proposed. According to the scheme, the WiMAX users are separated into a few clusters and the most favorable user is selected in each cluster to detect spectrum. A softened hard decision scheme is used to achieve a good tradeoff between the detection performance and the complexity. The analytical and simulation results show that the proposed approach can enhance the sensing performance and improve the spectrum efficiency by reducing the false alarm probability and the transmission overhead.