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Title of Thesis

Cross-term suppression in Wigner distribution

Author(s)

Nabeel Ali Khan

Institute/University/Department Details
Faculty of Engineering and Applied Sciences / Mohammad Ali Jinnah University, Islamabad
Session
2011
Subject
Electronic Engineering
Number of Pages
94
Keywords (Extracted from title, table of contents and abstract of thesis)
Methods, Affecting, Distribution, Signals, Frequency, Filters, Scheme, Cross, Representation, Suffers, Term, Developed, Wigner, Time, Suppression

Abstract
Wigner Distribution, one of many methods to compute time frequency representation, satisfies large number of mathematical properties and gives optimal energy concentration in time frequency plane.However, Wigner distribution suffers from severe cross-term interference problem, which limits its scope for practical applications.
Different modified versions of Wigner distribution have been developed to overcome its cross-term interference problem.Most of these techniques suppresses cross-term on the expense of quality of auto-terms.Schemes that compleltely remove cross-terms without affecting the resolution of Wigner distribution are computationally very expensive.
This research proposes a computationally efficient solution to cross-term interference problem based on image processing and fractional filtering. Signal components are located in time frequency plane using image processing.Fractional filters are then applied to separate signal components. Wigner distribution of separated signal components is computed and added up to obtain cross-term free crisp time frequency representation. Performance of the proposed time frequency representation is evaluated both on synthetic and real life bat signals.One of the most significant application of Wigner distribution is instantaneous
frequency estimation of signals.However, Wigner distribution based instantaneous frequency can only be applied to mono-component signal because of its crossterm problem. In this study we extend Wigner distribution based instantaneous frequency estimation scheme to multi-component signals having non-overlapping time frequency representation.

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2,298 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 CONTENTS

 

viii
51 KB
2

1

INTRODUCTION

1.1 Background
1.2 Objective
1.3 The Proposed Methodology
1.4 Contribution
1.5 Thesis Organization

1
 41 KB
3 2 REVIEW OF LITERATURE

2.1 Classical Signal Analysis Technique and need for t-f analysis
2.2 Time Frequency Techniques
2.3 Cross-term suppression techniques for WD

5
320 KB
4 3 CRITICAL ANALYSIS OF GABOR WIGNER TRANSFORM

3.1 Limitations of Gabor Wigner transform
3.2 Experimental Results

22
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5

4

CROSS-TERM SUPPRESSION USING 2D SIGNAL PROCESSING TECHNIQUES

4.1 Problem Formulation
4.2 The Proposed Approach
4.3 Step By Step Demonstration
4.4 Computational Cost Analysis
4.5 Mathematical Properties of the Proposed t-f distribution

28
802 KB
6

5

PERFORMANCE ANALYSIS OF THE PROPOSED TECHNIQUE

5.1 Quantitative measures
5.2 Performance Evaluation of the Proposed Technique
5.3 Comparison with schemes of Similar Performance
5.4 Conclusion

46
799 KB
7

6

INSTANTANEOUS FREQUENCY ESTIMATION

6.1 Review of IF Estimation Schemes
6.2 Problem Formulation
6.3 Modified signal separation scheme based on Fractional Filtering
6.4 Adaptive Instantaneous Frequency estimation
6.5 Results

61
385 KB
8

7

CONCLUSION AND FUTURE WORK

7.1 Conclusion
7.2 Future Work

71
42 KB
9

8

REFERENCES

 

75
54 KB