Signaling system for FM transmission systems
June 14, 2003. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3061783 3280260 3845391 Stereo sound reproducing apparatus with noise reduction Compatible stereophonic receiver Dual channel communications system particularly adapted for the AM broadcast band Radio broadcasting system with code signalling Radio broadcasting system with transmitter identification Apparatus and method for the identification of specially encoded FM stereophonic broadcasts In-band signaling system for FM transmission systems Patent #: 4388493 InventorApplicationNo. 06/504267 filed on 06/14/1983US Classes:381/4, AM subcarrier381/13, Antinoise381/14, Having transmitter381/6Having transmitterExaminersPrimary: Rubinson, Gene Z.Assistant: Brady, W. J. Attorney, Agent or FirmInternational ClassesH04H 5/00 (20060101)H04B 1/16 (20060101) AbstractA signaling system for FM transmission systems is disclosed that utilizes one or more so-called quadrature subcarriers for transmitting at least one data signal, including signaling tones, digital data, program material, or the like. The signal is modulated on outer edges of the quadrature channel so as to minimize crosstalk interference with the conventional FM stereo difference channel subcarrier and to place the signals in regions of low hearing acuity. Use of a quadrature subchannel also enables a signal to be modulated onto the quadrature subcarrier to provide the capability of modulating a noise compressed difference signal in a manner so as to minimize degrading crosstalk with the adjacent difference channel subcarrier. A receiving apparatus is disclosed for decoding the quadrature subcarrier data independently of standard FM stereo demodulation. | |
