Land mobile voice privacy communications
H.A. Hennen · 1980
The need for voice security in Land Mobile Radio communications is addressed, followed by a discussion of the thinking and engineering behind Motorola's development of a digital voice scrambler, the Digital Voice Protection (DVP) System. The radio hardware developed for the scrambler system is also described. Key technological advancements in realizing the DVP System were in the areas of large-scale integration (LSI)/hybrid technology and binary digital voice processing techniques. The DVP System utilizes 12,000 bit/sec. Continuously Variable Slope Delta modulation, a proprietary custom LSI CMOS (complementary metal oxide semiconductor) encryption device, and binary frequency shift keying for coded mode radio frequency transmission modulation.