AM Stereo Broadcasting system
US4458361A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 1982 |
| Grant date | Jul 3, 1984 |
| Priority date | — |
| Expiry date | May 11, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04H40/36
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An AM stereo broadcasting system for transmitting stereo signals in the AM broadcasting band. The system is based on amplitude modulation by two carriers having the same frequency and a 90.degree. phase difference from each other, and is capable of increasing the modulation depth of pilot signals (used for stereo signal identification) irrespective of the stereo signals, so that the pilot signals can be easily detected. By modulating both the sum and difference signals by the pilot signal, the receiver portion of the present system can derive the pilot signal irrespective of the stereo signals, thereby obviating many of the previous AM stereo broadcasting system problems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.