The Research Of Implementation Of Continuous Wavelet Transform Using Switched-Current Technology

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 have been used in signal processing. For the real-time requirements of signal processing in project, the study of using hardware to realize wavelet transform are developed rapidly.With the development of integrate circuit technics,it is possible that analog IC and digital IC are made in a same chip.Most of the mixed integrate circuits is digital,So circuit technics have the superiority to use digital CMOS process.The Swithched-Current circuit is a new technique for analog sampled data processing. The Switched-current circuits have conspicuous superiority in the compatibility with standard CMOS process. As a new type of analog circuits, the switched-current circuit works at the status of current mode and have the charactics of low voltage and low power. The design method of the circuits has the charactics of systematization and modularization, so it suits the implementation of the VLSI circuit of the continuous wavelet transform system.The paper researchs the implementation of the continuous wavelet transform system with analog circuit and the synthesis theory and design method of swithed-current 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 have a deep and systemic research on the switched-current as a new technology. The basic units of switched-current are analyzed for emphasis, especially the biquad units based on integrator or differentiator.Thirdly,the paper analyzes the ananlog circuit or mixed circuits that have realized several continuous wavelet transform.The paper research the implement of continuous wavelet transform using the technology of switched-current, that is a initiated work.The way that several biquads joined realize the wavelet function approximately is proposed.A wavelet filter bank of 8 channels is designed using the way, and the way is proved by the result of simulation using the Matlab and switched-current simulation soft.