Selective call signal detection circuit for multi-channel access type radio receiving station
US4597104A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 12, 1984 |
| Grant date | Jun 24, 1986 |
| Priority date | — |
| Expiry date | Oct 12, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W48/16
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A selective call signal detection circuit comprises a channel free/busy state detection circuit for scanning a plurality of communication channels to determine their respective free/busy states, a present-time channel free/busy state memory circuit for temporarily storing channel free/busy detection signals resulting from the aforementioned scanning of communication channels, a past-time channel free-busy state memory circuit for receiving into storage therein in the subsequent channel scanning cycle the channel free/busy detection signals of the previous scanning cycle formerly stored in the aforementioned present-time channel free/busy state memory circuit, and a comparison circuit for comparing the signals from the aforementioned present-time past-time channel free/busy state memory circuits thereby discriminating between a selective call signal addressed to a given receiving station and selective call signals addressed to other receiving stations. Since this selective call signal detection circuit permits quick discrimination between a channel in the state of normal communication and a channel in the state of selective call, it serves to enhance the efficiency of channel scanni…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.