Preface

There are many modern tools for learning digital signal processing (DSP): artificial intelligence (AI) software, easy-to-use interactive Jupyter notebooks, libraries such as Python’s scipy.signal, as well as environments such as Matlab and Octave. Still, despite the availability of these tools, a book retains major importance and plays significant roles.

A book is often the most appropriate format to define a coherent sequence of topics for a self-taught learner, establish consistent notation, present mathematical results, and so on. However, to coexist efficiently with modern learning tools, a book should now be integrated with them. This is the main design guideline of the present work. It is intended to be used as a companion to the tools listed at http://www.aldebaro.ufpa.br, which include software, slides, and an AI-based chatbot. These tools are collectively referred to as “bootor”: a book-based tutor.

The contents of this book were organized with the well-known exploration-exploitation tradeoff in mind. DSP is a broad field with many excellent and comprehensive textbooks. However, a conventional curriculum still requires a significant amount of time to adequately prepare the student.¹ A slow process of building maturity often underestimates students and hinders the interest in DSP. A well-designed curriculum should not excessively postpone the adoption of advanced software and mathematical concepts. Instead, it should select a subset of relevant topics for exploitation while deliberately limiting exploration. Traditional DSP classes often delve deeply into numerous properties and details,² before addressing real-world applications with tools adopted by industry.

Throughout my career, I have worked on research and development projects focused on solving real-world problems. Along this path, I had the privilege of advising more than 90 graduate students who successfully completed their degrees and secured strong positions in academia and industry. My experience indicates that once students recognize the importance of DSP for their careers and employability, they naturally fill in any gaps in their knowledge when needed, compensating for the intentionally limited exploration of DSP “properties and details”.

Therefore, this book departs from the traditional sequence of topics commonly adopted in DSP education. It primarily targets self-taught readers with a bias toward practical application. With the support of an appropriate book-based tutor, students can aspire to achieve a level of proficiency comparable to that of graduate students without necessarily following a path based on multiple textbooks. In particular, this bootor was developed to quickly train readers / users to solve advanced DSP problems by learning software and math together.

I thank everyone who contributed to this effort, especially my family, friends, professors, students, and colleagues at UFPA and other universities, as well as researchers at Ericsson, Brasilsat, and other companies with which I have collaborated. I dedicate this book to my spouse, Sonja, a wonderful person who has made me happy and in love throughout these fast-moving 28 years. I only wish I had not waited so many months to marry her! :) Finally, I express my gratitude to God for everything. In a context of far greater significance, Saint Pope John Paul II (whom I saw during his visit to my hometown in 1980) taught: “man becomes what he contemplates”. May interacting with this bootor inspire you to develop both skill and a lasting appreciation for DSP.

¹ Engineering programs often require several courses (e.g., “Signals and Systems”, “Digital Signal Processing”, and “Stochastic Processes”) before challenging students to develop solutions using tools commonly adopted in industry, such as Git and large open-source software systems.

² For example, distinct left-sided and right-sided sequences can have the same Z-transform, highlighting the need to know the region of convergence to uniquely recover the time-domain sequence. However, this knowledge is rarely essential in practical DSP problem-solving.