Research And Hardware Implementation Of Discrete Wavelet Transform

With the increasing complexity of modern digital signal processing technology,people pay more and more attention to the processing of unstable digital signals.As one of the new generation digital signal processing technologies,wavelet transform is an ideal tool for time-frequency analysis of digital signals,and has a wide range of applications in signal denoising,video image compression,image edge detection and other fields.In this paper,firstly,the application of discrete wavelet transform in signal denoising is studied,and an improved wavelet threshold denoising algorithm is proposed;then the hardware structure design of discrete wavelet transform is studied.The main work contents are as follows:1. Based on the traditional wavelet threshold denoising algorithm,the existing threshold function and threshold selection method are improved.The new threshold function has better continuity and smaller coefficient deviation,and the new threshold selection method has higher removal rate of noise signal.2. Design and implement the hardware structure of one-dimensional and two-dimensional discrete wavelet transform from the perspective of data calculation dimension.First,the hardware architecture of the universal one-dimensional discrete wavelet transform is implemented on the structure of the convolution filter bank based on the Mallat algorithm,and then the hardware architecture of the three-level two-dimensional discrete wavelet transform is designed and implemented in combination with the multi-level expansion and line parallel structure.3. Perform functional verification and performance test for the one-dimensional and two-dimensional discrete wavelet transform hardware structure on Xilinx XC7V2000T FPGA.The test results show that the universal one-dimensional discrete wavelet transform hardware structure designed in this paper supports multiple wavelet-based discrete wavelet transforms,and the two-dimensional discrete wavelet transform hardware circuit structure designed in this paper can complete the three-level discrete wavelet transform of db2 wavelet.For fixed-point data,both architectures can provide a result accuracy of 10^-3.