Multipath Channel Parameter Estimation in Mobile Radio Environments Using Stationary Wavelet Transform

2005 ◽  
Author(s):  
O.A. Aboaba ◽  
Kah-Seng Chung
Keyword(s):  
Parameter Estimation ◽  
Wavelet Transform ◽  
Mobile Radio ◽  
Multipath Channel ◽  
Stationary Wavelet Transform ◽  
Channel Parameter

An Adaptive Rayleigh-Laplacian Based MAP Estimation Technique for Despeckling SAR Images using Stationary Wavelet Transform

2013 ◽  
Vol 4 (4) ◽  
pp. 88-102
Author(s):  
Amlan Jyoti Das ◽  
Anjan Kumar Talukdar ◽  
Kandarpa Kumar Sarma
Keyword(s):  
Parameter Estimation ◽  
Wavelet Transform ◽  
Speckle Noise ◽  
Posteriori Probability ◽  
Wavelet Coefficients ◽  
Stationary Wavelet Transform ◽  
Sar Images ◽  
Edge Information ◽  
A Posteriori Probability ◽  
Map Estimator

Removal of speckle noise from Synthetic Aperture Radar (SAR) images is an important step before performing any image processing operations on these images. This paper presents a novel Stationary Wavelet Transform (SWT) based technique for the purpose of removing the speckle noise from the SAR returns. Maximum a posteriori probability (MAP) condition which uses a prior knowledge is used to estimate the noise free wavelet coefficients. The proposed MAP estimator is designed for this purpose which uses Rayleigh distribution for modeling the speckle noise and Laplacian distribution for modeling the statistics of the noise free wavelet coefficients. The parameters required for MAP estimator is determined by technique used for parameter estimation after SWT. Moreover an Laplacian – Gaussian based MAP estimator is also applied and the parameter estimation is done using the same method used for the proposed algorithm. For the purpose of enhancing the visual quality and to restore more edge information, a wavelet based resolution enhancement technique is also used after applying the Inverse stationary Wavelet Transform (ISWT), using interpolation technique. The experimental results show that the proposed despeckling algorithm efficiently removes speckle noise from the SAR images and restores the edge information as well.

Channel parameter estimation in mobile radio environments using the SAGE algorithm

1999 ◽  
Vol 17 (3) ◽  
pp. 434-450 ◽  
Author(s):  
B.H. Fleury ◽  
M. Tschudin ◽  
R. Heddergott ◽  
D. Dahlhaus ◽  
K. Ingeman Pedersen
Keyword(s):  
Parameter Estimation ◽  
Mobile Radio ◽  
Channel Parameter
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