中文摘要：

在认知超宽带（cognitive ultra-wideband，CUWB）通信系统中，检测与躲避（detection and avoidance，DAA）策略通过感知首要用户（primary user，PU）所处频段，然后用脉冲波形设计等方法来规避所占频段以获得共存通信的效果。提出了一种新的DAA-CUwB共存通信方案，首先设计多尺度的宽带频谱检测算法来感知PU所用频段，粗细尺度结合的检测方式保证频谱的准确检测和较低的复杂度，进而提出基于多通道正交频域编码的脉冲成形设计算法，来避开被PU占据的频段，最大化CUwB的频谱利用率。利用理论分析和仿真测试验证了所提出的DAA算法的特性，并通过性能仿真进一步论证了共存方案的有效性，实验结果表明cUwB和Pu都能保证各自系统性能，并最大化地共享了频率资源。

英文摘要：

The coexistence communications hetween cognitive ultra-wideband （CUWB） and primary us- er can be implemented by the strategy of detection and avoidance （DAA） , in which the spectrum sensing and evading to the primary user are employed in CUWB. A novel DAA CUWB algorithm is proposed. For the spectrum detection, a multi-scale sensing scheme is designed to obtain high detection accuracy and low-com- plexity~ then a pulse shaping based on multi-channel orthogonal frequency coding （MC-OFC） is proposed to avoid the occupied spectrum and improve spectral usage. The effectiveness of the proposed DAA scheme is studied via theoretical analysis. Simulations are also employed for proving the reliability of the coexistence of the primary user and CUWB. Both of them are able to guarantee the performance of their individual system, and the spectrum utilization is thus maximized.