小波变换的单开关电流积分器设计实现方法

Wavelet transform implementation method using single switched-current integrator

针对小波变换的模拟电路实现问题,提出一种基于单开关电流积分器的模拟小波变换电路设计新方法。根据小波变换的模拟滤波器实现原理,以某一带通滤波器传递函数为例,首先,基于小波函数的容许条件,证明该网络函数为母小波函数;然后,采用单开关电流积分器为基本单元设计冲激响应为该母小波的带通滤波器,通过调节滤波器电路时钟频率获得不同尺度小波函数实现小波变换。研究结果表明:该方法实现小波变换具有无需小波函数逼近过程、设计精度高、电路结构简单、小波函数尺度易于调节等特点,适合于低压、低功耗和实时工程应用。

In order to solve the problem of analog circuit implementation of wavelet transform（WT）, a novel method for implementing analog WT was presented using single switched-current （SI） integrator circuit. Firstly, according to the theory of WT implementation using analogue filters, the network function of a bandpass filter was selected as an example and proved that it was a mother wavelet function（WF） based on the admissible condition of the WF. Then the bandpass filter with its impulse response being the mother WF was designed using signal SI integrator. The different scale wavelet functions of the WT were obtained by adjusting the clock frequency of the wavelet filter. The results show that the designed circuits have many characteristics, such as high design precision without the WF approximation process, simple circuit structure and easily adjustment WF scales. Therefore, the proposed circuits are suitable for low voltage low power and real-time engineering applications.