I don’t know about the HW but there is a very nice textbook from Misra and Enge, second edition, 2006, titled “Global Positioning System: Signals, Measurements, and Performance”.
This bood gives an overview of the transmitted/received signals and processing.
If you want a set of legendary historic papers about the GPS, you may want to look at “Global Positioning System: Theory and Applications Volume 1” edited by Parkinson and Spilker Jr. This book covers fundamental design aspect of the GPS and many more.
Volume 2 of this book describes various areas of applications with the GPS.
All of these plus many more can be found at <a href=http://www.navtechgps.com/
target=_blank>http://www.navtechgps.com/
In my experiences, they have more books about the GPS and they are cheaper than amazon.com.
