The Research Of Implementation Of Wavelet Function And Continuous Wavelet Transform Using Log-domain Circuit

The Wavelet transform is a new style mathematic analysis tool developed in 1980s. It has characteristic of multi-resolution. The CWT is a powerful tool in analyzing the unstable signals and has been used in signal processing. For the real-time requirements of signal processing in project, the study of using hardware to realize wavelet transform has been developed rapidly.Instantaneous companding circuit, namely, Log-domain circuit, is the key technique used by international academia to develop the low-voltage and low-power analog VLSI in recent years. It effectively solves the dilemma aroused by low-voltage power, noise and high-frequency property, thus provides the favorable dynamic range and low-power cost for the system, which is one of the important methods to fulfill the IC design of the CWT. The design method of the circuits has the characteristics of systematization and modularization, so it suits the implementation of the VLSI circuit of the continuous wavelet transform system. As a result of a trailblazing research in the world, it can offer us a new method for the VLSI synthesis of wavelet transform in real-time.The paper concentrates on the implementation of the continuous wavelet transform system with analog circuit and the synthesis theory and design method of log-domain circuits. Firstly, the knowledge about the wavelet transform is introduced.The characteristic of time- frequency and multi-resolution about wavelet transform is introduced in detail. Secondly, the paper does a deep and systemic research on the log-domain circuits as a new technology. Then we propose a kind of differential circuit implemented by the instantaneous companding technique and we analyze its principle and execute circuit's simulation. And we realize a kind of wavelet Function with the differential circuit. The paper proposes a new kind of continuous wavelet transform and processing circuits where the wavelet transform is fulfilled by demodulation process. We analyze its primary circuits, and its PSPICE simulations indicate a wide dynamic range employed by low-voltage and low-power. We design and analyze the parameters of a 6-channel audio-wavelet transform system. At last, we explore several factors in the circuits which may affect the circuits'properties.