There is now a mini-library of published books available on the subject of digital terrestrial radio broadcasting. Two are domestic and technical; the other two are more globally-oriented and critical. (I’m writing the domestic-critical book!)
First up is the oldest: The IBOC Handbook: Understanding HD Radio™ Technology is a must-read for any broadcast engineer saddled with the task of implementing HD on a broadcast station. Published by the National Association of Broadcasters and authored by David Maxson, the book is an excellent technical overview of the protocol as well as its potentials and pitfalls. (It’s also the only one of the books I’ve actually read yet.)
HD Radio Implementation: The Field Guide for Facility Conversion was written by Thomas Ray III, WOR’s chief engineer and (until recently) a very staunch proponent of HD Radio. If you’re a broadcast engineer faced with HD, this is the second book you should read – Maxson’s book explains the theory, while Ray’s book looks at the issue from the applied angle – how to not only just install, adjust, and maintain an HD signal, but also how to optimize the entire station’s air chain to accommodate it.