An alternative approach for implementing a multiband VHF/UHF handled radio with narrowband secure voice
D.C. Grusell, A. Neuburger, David Penny, W.F. Sullivan · 2003
The authors outline a concept for a handled radio which utilizes 2.4-kb/s LPC-10 linear predictive voice encoding, error correction coding and decoding, digital modulation, and hybrid radio-frequency (RF) techniques. The intent is to achieve a handheld radio which can operate in 12.5-kHz channels over the low VHF, high VHF, and UHF bands. Such a radio would achieve better communications performance at lower cost and with greater reliability by a shared use of a digital signal processor and a microprocessor and by an RF design which obviates the need for interchangeable RF modules. Continuously variable slope delta (CVSD) modulation, encryption devices, and FM are used to implement digitized secure voice. Multiband operation is achieved using interchangeable RF modules.>