tailieunhanh - Báo cáo hóa học: " Research Article Adaptive Optimal Kernel Smooth-Windowed Wigner-Ville Distribution for Digital Communication Signa"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Adaptive Optimal Kernel Smooth-Windowed Wigner-Ville Distribution for Digital Communication Signa | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2008 Article ID 408341 17 pages doi 2008 408341 Research Article Adaptive Optimal Kernel Smooth-Windowed Wigner-Ville Distribution for Digital Communication Signal Jo Lynn Tan and Ahmad Zuri bin Sha ameri Department of Microelectronic and Computer Engineering Universiti Teknologi Malaysia Skudai 81310 Johor Malaysia Correspondence should be addressed to Jo Lynn Tan tjolynn82@ Received 20 February 2008 Revised 25 August 2008 Accepted 18 November 2008 Recommended by Ricardo Merched Time-frequency distributions TFDs are powerful tools to represent the energy content of time-varying signal in both time and frequency domains simultaneously but they suffer from interference due to cross-terms. Various methods have been described to remove these cross-terms and they are typically signal-dependent. Thus there is no single TFD with a fixed window or kernel that can produce accurate time-frequency representation TFR for all types of signals. In this paper a globally adaptive optimal kernel smooth-windowed Wigner-Ville distribution AOK-SWWVD is designed for digital modulation signals such as ASK FSK and M-ary FSK where its separable kernel is determined automatically from the input signal without prior knowledge of the signal. This optimum kernel is capable of removing the cross-terms and maintaining accurate time-frequency representation at SNR as low as 0 dB. It is shown that this system is comparable to the system with prior knowledge of the signal. Copyright 2008 J. L. Tan and A. Z. B. Sha ameri. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION Bilinear time-frequency analysis has been widely used to analyze time-varying signals such as in speech music and other acoustical signals sonar radar