一种新的连续小波变换VLSI实现方法

A new VLSI implementation of the continuous wavelet transform

研究了连续小波变换的VLSI实现方法。利用2个周期函数相乘得到小波信号链,与待分析信号经过乘法器相乘,再经过低通滤波器处理,得到信号的时频分解,也就是得到待分析信号的局部放大信号。乘法器采用的是InP衬底的异质双极晶体管(HBT)的Gilbert乘法器,低通滤波器采用的是压缩扩展的对数域电路。首次采用电流模式压缩扩展对数域电路来实现一维连续小波变换,这种实现具有高速、低电压、低功耗等特点。用PSPICE,Matlab对乘法器和滤波器等小波变换基本器件及小波重构进行仿真,表明所提出的连续小波变换压缩扩展电路可行。

This paper proposed a VLSI implementation of the continuous wavelet transform. The proposed approach consists of generating a chain of wavelets by multiplying two periodic functions. Each wavelet is then multiplied by the signal to be analyzed,and integrated and time-frequency decomposition of signal,i, e. partial zoom of the analyzed signal can be gained. The multiplier is a InP HBT Gilbert muhiplier,and the low-pass filter is a companding log-domain circuit. In the paper first used current - mode companding circuit technology to implement 1 - D continuous wavelet transform,which has a characteristic of high-speed,expanded frequency, simplified and low-vohage low-power. The PSPICE and Matlab simulation of the reconstruction and the basic cell such as multiplier and LPF are given. The results show that the continuous wavelet transform companding circuit proposed in the article is feasible.