Further Notes and Anecdotes on Spread-Spectrum Origins

This sequel to R. A. Scholtz's monograph of May 1982, in this TRANSACTIONS, adds to the early history of spread-spectrum communications from circa 1900 until about 15 years ago. Relevant to the origins of this field of radio signaling, the following are included in a number of items of quite recent appreciation: the 1930 invention of secret communications featuring spectrum despreading via a locally generated reference at the receiver; a stratagem of electronic warfare during the Battle of the Bulge, in World War II, that cleverly made use of Armstrong's frequency modulation; and the role of a star actress from the motion picture field, in origination of frequency hopping for antijamming radio control of missiles. Some further, and first-hand, reminiscences are given of germinal M.I.T. spread-spectrum contributions, and of similar noise-correlation radar art. Extensive footnotes cast sidelights on the beginnings of information theory, and also, among other things, on the keeping of military high-technology secrets over decades, even between securitycleared family members. A variety of references is appended.