Design and performance of a digital voice privacy system for land mobile radio

This paper presents the design and performance of a 9600 bits/sec digital voice privacy system. The system has been applied in commercially available mobile radio products. Various aspects of the design such as speech bandwidth compression, encryption and radio engineering will be discussed. The resulting performance from a radio frequency standpoint is presented. Performance characteristics will show that certain limitations of previously available commercial mobile radio voice privacy products are overcome in this design.