嵌入式硬件设计参考系列之DSＰ导论.pdf INTRODUCTION SECTION 1 INTRODUCTION 1.a INTRODUCTION 1.b INTRODUCTION SECTION 1 INTRODUCTION Walt Kester ORIGINS OF REAL-WORLD SIGNALS AND THEIR UNITS OF MEASUREMENT In this book, we will primarily be dealing with the processing of real-world signals using both analog and digital techniques. Before starting, however, let's look at a few key concepts and definitions required to lay the groundwork for things to come. Webster's New Collegiate Dictionary defines a signal as "A detectable (or measurable) physical quantity or impulse (as voltage, current, or magnetic field strength) by which messages or information can be transmitted." Key to this definition are the wo……