Combined trunked/cellular communication unit
US5175872A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 28, 1991 |
| Grant date | Dec 29, 1992 |
| Priority date | — |
| Expiry date | Mar 28, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W88/06
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A communication unit (10), capable of operating in either cellular or trunked communication modes, comprises a receiver (14), a transmitter (16), and a dual synthesizer (18), coupled to the receiver and to the transmitter. The dual synthesizer comprises a main synthesizer (124) and an offset synthesizer (132). The offset synthesizer comprises a phase modulator (131) and an offset voltage-controlled oscillator (134). A protocol controller (20) comprises modulator circuitry for modulating only the offset voltage-controlled oscillator when communication unit operates in the cellular mode, and for modulating both the phase modulator and the offset voltage-controlled oscillator when the communication unit operates in the trunked mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.