System for short range transmission of a plurality of signals simultaneously over the air using high frequency carriers
US5491839A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 28, 1993 |
| Grant date | Feb 13, 1996 |
| Priority date | — |
| Expiry date | May 28, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04H20/48
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A transmitter/receiver system for the simultaneous transmission and reception of plural audio signals over the air for a short range using carrier signals of frequencies over 900 MHz. A combined signal having a plurality of carrier signals, each modulated by a different audio signal, is transmitted. The receiver, separated from the transmitter by a distance of 10 to 300 feet, receives the combined signal and the listener then selects one of the frequency modulated carrier signals in the combined signal at the receiver with a selector switch. One of a set of combined signals is selected at the transmitter, allowing for a choice of different frequencies for transmission, to avoid interference with other systems in the vicinity. Moreover, where predetermined, e.g., fault, conditions occur in the transmitter and/or receiver, muting circuits within the receiver are activated for the duration of the predetermined, e.g., fault, condition to silence the audio output signal to the listener and thereby prevent the thumping and hissing that a listener usually experiences during power transients and unlocked signal conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.