为了解决认知超宽带与窄带系统共存问题,实现认知超宽带无线电自适应波形设计,采用高斯函数的加权叠加作为认知超宽带脉冲波形.通过将波形设计问题转化为线性滤波器设计问题,采用Parks—McClellan算法进行求解,实现了任意中心频率和带宽陷波的波形设计.并进一步提出了利用权重值数组控制不同频带陷波深度的方法.仿真结果表明,所设计波形的功率谱密度在WLAN频段上可以实现约-30dB的陷波,同时也可以实现多个频段陷波的波形设计.根据实际需要选择权重值可以控制各个频段的陷波的深度.
Ultra-wide band (UWB) systems must coexist with narrow band systems and implement adaptive use of available bandwidth for cognitive UWB (CUWB) radio. To deal with these challenges, a weighted superposition of the Gaussian function was used as the CUWB pulse waveform. By transforming waveform design into a linear filter design, and then solving the problem with the Parks-McClellan method, spectral notches centered at any frequency and bandwidth were produced. Then a weighting factor was introduced into the waveform design algorithm to control the depth of the spectral notches at different frequencies. Simulation results showed that the power spectrum of the waveform could be made with a -30dB notch depth on the wireless local area network (WLAN) band. This algorithm can also produce a waveform with multiple spectral notches. To deal with actual conflicts, varying notch depths at different frequency bands can be produced by changing the weighting factor.