Analogue VLSI implementations of wavelet transform based on switched-current technology

Hardware implementation is an optimum approach to the real-time application of wavelet transforms. In this paper, a novel method of implementing wavelet transform using switched-current (SI) technology is presented. Analog VLSI implementation procedure mainly involves the construction of a bank of filters whose impulse responses are the basic wavelet function and its dilations. SI circuits are well suited for this application since the dilation constant across different scales of the transform can be implemented and controlled by the clock frequency precisely. Therefore, the main focus just is on the SI circuit implementation of the basic wavelet function filter. The Marr wavelet is selected as an example with construction procedure and structure of SI circuits elaborated, in which the second-generation SI circuit is employed. Theoretical analysis and simulation results indicate that the proposed method is feasible.