A Noise Cancelling Technique Using Non-uniform Filter Banks and Its Implementation on FPGA

The problem of estimating a signal that is corrupted by additive noise has been a interesting theme of digital signal processing field for several decades. Due to advantages over the linear methods, nonlinear methods based on wavelet transform have become increasingly popular. It has been shown that wavelet-thresholding algorithm generates near-optimal properties in the minimax sense. However, the wavelet-thresholding algorithm is very complex and difficult to implement it on hardware such as Field Programmable Gate Array(FPGA). Therefore, we need alternative simple approach for noise cancelling. In this paper, we propose a new noise cancelling algorithm with the binary tree structured filter banks and implement it on FPGA. To cancel the noise, we use the signal power ratio of each subband. For simple implementation, the filter banks are designed by Hadamard transform coefficients. From the results of simulations and hardware implementation, we show that the proposed algorithm produces a good results.