Wireless communications is rapidly becoming one of the ubiquitous technological underpinnings of modern society (such as electric power, fossil fuels, automobiles, etc.). Few people think about the technology within their mobile phones, remote controls, garage door openers, GPS navigation devices, and so on. These devices are always at hand and reliably work for the user.
Yet even within the electrical engineering (EE) community, radio communication techniques have a reputation as a “Black Art” that can only be successfully practiced by “RF people”. This is changing, albeit slowly. Any significant progress in successfully opening this vital technology widely to more practitioners must remove this “Black Art” stigma. In my opinion this is best achieved through outreach from existing successful “RF people”. This outreach must occur through many channels, such as this book and new courses in both academic and industrial training.
Today it takes many years to train communications engineers in the intricacies of wireless signal modulation tradeoffs. I am a product of this decades-long process. Much of this difficulty, for me anyway, is a consequence of the mathematical approach taken to all modulation training. The objective of this book is to begin to add a comprehensive yet physical approach alongside this traditional modulation training.
The contents of this book are drawn from the nearly 40 years of experience I have with radio communication technology. Being much more of a physics-based person instead of a mathematician, to build my own understanding of this material over these decades I have put in a lot of effort to get through the mathematics and into also understanding the underlying physical relationships. Through these pages I can share my results with you. One major premise of this book comes from advice I received from my father as I began learning electronics: “Don’t memorize equations to learn the material. Instead, carefully learn the fundamental principles. Then as you need an equation, if it is not memorized it can be quickly derived on the spot.” He lived by this rule, and it has definitely served me very well over the years. And now in the age where computers do much of the math anyway, it is vital to be able to check any computer output for reasonableness. A surprising output may be the result of a programming error which can be quickly fixed to avoid embarrassment. Then again, it may be a clue to a significant technology contribution. The difference can only be known if fundamental physical principles are well understood.