基于小波的优化组合认知超宽带波形设计方法

研究了认知超宽带(CUWB)脉冲波形设计问题,提出了一种基于Morlet小波的优化组合CUWB波形设计方法。在分析Morlet小波时频特性的基础上,制定了该方法的设计实现步骤。首先由“二分法”获得符合FCC频率掩模要求的小波伸缩因子选值区间,其次通过设计可编程逻辑语言来寻找最优组合权值,获得高频谱效率的UWB脉冲波形。综合考虑认知用户检测到的授权用户频段,设计阻带滤波器进行窄带干扰抑制,将UWB脉冲波形通过滤波器后可得CUWB脉冲波形。仿真实验表明:该方法易于实现和操作,设计波形具有良好的自相关性和高频谱利用率,方法为CUWB的波形设计问题研究提供了一种新的思路。

A Waveform Design Method of Cognitive Ultra Wide Band Communications Based on Optimized Combination Wavelet

Pulse waveform design problems of cognitive ultra wide band (CUWB) are studied, and a method of optimized combination Morlet wavelet is proposed. On the basis of characteristic analysis in time and frequency domain of Morlet, the design steps of the method are worked out. Firstly, the value area of wavelet stretching factor is acquired by the use of dichotomy method under the action of power spectrum density (PSD) met the needs of FCC spectral mask. Then, optimized weight is searched by designing programmable logistic language so as to get combined UWB pulse with high frequency spectrum efficiency. In consideration of authorized frequency band detected by cognitive user, band-stop filter is designed for suppressing narrow band interference, thus CUWB pulse waveform is got by making UWB pulse pass the designed filter. The simulation shows that the proposed method is susceptible to realization and operation, the designed waveform has good autocorrelation character and high spectrum utilization ratio, which provides a new thought for waveform design of CUWB.