Design and Performance of a Spread Spectrum Data Communications System Using Delta Modulation with a Dithered Clock.
Evangelos Vassilios Pappas, James H. Hoffman · Calhoun: The Naval Postgraduate School Institutional Archive (Naval Postgraduate School) · 1978
Digital modulation schemes and spread spectrum techniques are of major importance in modern communications. This thesis investigates a delta modulation/demodulation scheme and direct sequence spreading of the digital data. The clock rate is dithered to enhance the low probability of intercept advantage of spread spectrum. The circuitry incorporates small and medium scale integrated circuits. Experimental results are presented in some detail. Good quality voice and music were recovered using a fixed bit rate as low as 10 kbits/sec and a clock dither range of 40%. (Author)