You can download the PDF version of John R. Barry's book on digital communication from various online sources. However, please ensure that you have the necessary permissions or rights to access the PDF.
If you want, I can:
Deterministic Signal Processing. Error Control. John R. Signal-Space Coding. Multiple Access Alternatives. Springer Nature Link Digital Communication - Chess 8 Aug 2012 — digital communication john r. barry pdf
: Equalization (Adaptive and MIMO), Timing Recovery, and Carrier Recovery You can download the PDF version of John R