Mobile communication apparatus
US4817197A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 1987 |
| Grant date | Mar 28, 1989 |
| Priority date | — |
| Expiry date | Jul 13, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03J5/0281
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Local frequency which is subject to fluctuate in a mobile subscriber set is locked to stable transmit frequency of a base station. A mobile subscriber set (FIG. 3) for angle modulated signal has a frequency mixer (3.6, 3.9), for converting wireless receive frequency to an intermediate frequency by using local frequency (F.sub.L1, F.sub.L2), a limiter (3.11) for limiting amplitude of intermediate frequency signal, a discriminator (3.12) for demodulating angle modulated signal, a standard oscillator (3.1) by using a quartz crystal oscillator and a synthesizer (64) for providing local frequency for said mixer (3.6), a digital frequency counter (3.14) for measuring intermediate frequency, and control means (3.16) for adjusting said standard oscillator (3.1) depending upon error of intermediate frequency measured by said counter (3.14).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.