A Signal Denoising Method of Gesture Radar Based on Weighted Principal Component Analysis and Improved Wavelet Threshold

When using radar to recognize gesture, radar echo signals are susceptible to noise. In order to improve detection resolution and data interpretation quality of gesture radar, this paper proposes a new denoising algorithm based on weighted principal component analysis and improved wavelet threshold, named WPCA-IWT denoising algorithm. First, radar echo data are standardized and each echo data’s variance are calculated. Each echo data is multiplied by it’s corresponding variance to complete weighting operation. By using WPCA processing, the dimension of echo data is reduced and echo signal’s principal components are extracted. Then, a new threshold function is proposed and an improved wavelet threshold denoising algorithm is designed to denoise principal components. Finally, denoised principal components are multiplied with an eigenvector matrix to reconstruct radar echo. The proposed WPCA-IWT denoising algorithm has obvious advantages at the aspects of efficiency and denoising effect. Both simulation and on-site radar data experiments verified the effectiveness of the proposed algorithm.

[1]  Ali M. Niknejad,et al.  A 94GHz mm-wave to baseband pulsed-radar for imaging and gesture recognition , 2012, 2012 Symposium on VLSI Circuits (VLSIC).

[2]  Peng Yang,et al.  A weighted PCA based denosing for the spectrum signal in laser induced breakdown spectroscopy , 2016, 2016 9th International Congress on Image and Signal Processing, BioMedical Engineering and Informatics (CISP-BMEI).

[3]  E. Ambikairajah,et al.  An improved soft threshold method for DCT speech enhancement , 2008, 2008 Second International Conference on Communications and Electronics.

[4]  Takuya Sakamoto,et al.  Radar-based hand gesture recognition using I-Q echo plot and convolutional neural network , 2017, 2017 IEEE Conference on Antenna Measurements & Applications (CAMA).

[5]  Olga Boric-Lubecke,et al.  Barcode based hand gesture classification using AC coupled quadrature Doppler radar , 2016, 2016 IEEE MTT-S International Microwave Symposium (IMS).

[6]  David L. Donoho,et al.  De-noising by soft-thresholding , 1995, IEEE Trans. Inf. Theory.

[7]  Hong Li,et al.  FMRSS Net: Fast Matrix Representation-Based Spectral-Spatial Feature Learning Convolutional Neural Network for Hyperspectral Image Classification , 2018, Mathematical Problems in Engineering.

[8]  T. Jagadesh,et al.  A novel speckle noise reduction in biomedical images using PCA and wavelet transform , 2016, 2016 International Conference on Wireless Communications, Signal Processing and Networking (WiSPNET).

[9]  A. ALSHAMALI Wavelet based ECG compression with adaptive thresholding and efficient coding , 2010, Journal of medical engineering & technology.

[10]  Friedrich Jondral,et al.  Feature-based gesture classification by means of high resolution radar measurements , 2017, 2017 18th International Radar Symposium (IRS).

[11]  Xiaohan Sun,et al.  TWT output signal denoising based on improved wavelet threshold , 2017, 2017 Eighteenth International Vacuum Electronics Conference (IVEC).

[12]  I. Johnstone,et al.  Adapting to Unknown Smoothness via Wavelet Shrinkage , 1995 .