Donald L. Schilling was a pioneering communications engineer whose breakthroughs in spread spectrum, CDMA, MIMO, and HSPA helped shape today’s 3G, 4G, and 5G systems. His innovations earned top honors including the IEEE Medal of Honor and the National Medal of Technology and Innovation, reflecting “the significant impact that his work had on modern communication systems.” Remembered as “one of the great contributors to 20th century (and 21st century) communications technology,” he authored 12 textbooks, over 200 papers, more than 125 patents, and a novel, “The Enterprise, Book 1”.