If you cannot find a legal PDF link, the used hardcover market is your friend (eBay, Abebooks). Older editions (1st edition) are perfectly fine; digital communications theory hasn't changed much in the last decade outside of massive MIMO and 5G, which this book covers conceptually. You arrived here looking for a shortcut—a direct "introduction to digital communications ali grami pdf link." While this article cannot provide an illegal copy, it provides something more valuable: the knowledge of how to legally acquire the digital file for pennies on the dollar via your university library.
Sets the stage, comparing analog vs. digital systems, and introduces the Shannon-Hartley theorem. introduction to digital communications ali grami pdf link
This is the heart of the book. Grami excels here, explaining Quadrature Amplitude Modulation (QAM) using constellation diagrams that are far clearer than those in Proakis’s text. If you cannot find a legal PDF link,