Back to results
US 5,850,415 AGranted
In-band on-channel digital broadcasting
AssigneeUSA Digital Radio Partners, L.P.
InventorsBillie J. Hunsinger, A. J. Vigil, Leland P. Solie
Life of this patent
Estimating the term…
Abstract
A system for combining AM and FM transmissions. In-band, On-channel, FM Digital Audio Broadcast (IBOC FM-DAB) allows simultaneous transmission of DAB and FM over existing FM allocations without interfering with conventional analog FM signals. The utility of existing FM spectrum allocations is therefore enhanced.
Claims9
A method for transmitting an in-band on-channel frequency modulation digital broadcast signal, comprising the steps of:
- a) frequency modulating an FM message to produce an FM waveform;
- b) demultiplexing a DAB serial data message to produce a plurality of digital data subchannel signals;
- c) modulating the digital data subchannel signals to produce digital data subchannel waveforms;
- d) combining the FM waveform with the digital data subchannel waveforms to produce a first signal;
- and combining the FM waveform with said first signal to generate an in-band on-channel frequency modulation digital broadcast signal, wherein said in-band on-channel frequency modulation digital broadcast signal comprises said plurality of subchannel waveforms spectrally arrayed around said FM waveform, said subchannel waveforms slewing in frequency with said FM waveform.
2 more elements
A method for receiving and demodulating a plurality of information signals modulated into an in-band on-channel frequency modulated digital broadcast signal, comprising:
- a) converting the in-band on-channel frequency modulated digital broadcast signal to an intermediate frequency signal;
- b) separating the intermediate frequency signal into a first demodulated baseband FM message and a second DAB AM baseband message;
- c) producing from said second message a matched filtered waveform, wherein parameters which produce said matched filtered waveform are dynamically determined by examination of history of said second message;
- and
- d) demodulating the matched filtered waveform to generate a digital data signal.
2 more elements
Apparatus for producing an in-band on-channel digital broadcast signal, comprising:
- a) means for frequency modulating an FM message to produce an FM waveform;
- b) means for demultiplexing a DAB serial data message to produce a plurality of digital data subchannel signals;
- c) means for modulating the digital data subchannel signals to produce digital data subchannel waveforms;
- d) means combining the FM waveform with the digital data subchannel waveforms to generate a double sideband suppressed carrier AM over FM signal;
- and
- e) means combining the FM waveform with the double sideband suppressed carrier AM over FM signal to generate an in-band on-channel frequency modulation digital broadcast signal, wherein said in-band on-channel frequency modulation digital broadcast signal comprises said plurality of subchannel waveforms spectrally arrayed around said FM waveform, said subchannel waveforms slewing in frequency with said FM waveform.
3 more elements
A receiver comprising:
- a) means converting an in-band on-channel frequency modulated digital broadcast signal to an intermediate frequency signal;
- b) means separating the intermediate frequency signal into a first demodulated baseband FM message and a second DAB AM baseband message;
- c) means producing from said second message a matched filtered waveform, wherein parameters which produce said matched filtered waveform are dynamically determined by examination of history of said second message;
- and
- d) means demodulating the matched filtered waveform to generate a digital data signal.
2 more elements
Apparatus for broadcasting and receiving an in-band on-channel digital broadcast, comprising:
- a) means for frequency modulating an FM message to produce an FM waveform;
- b) means for demultiplexing a DAB serial data message to produce a plurality of digital data subchannel signals;
- c) means for modulating the digital data subchannel signals to produce digital data subchannel waveforms;
- d) means combining the FM waveform with the digital data subchannel waveforms to generate a double sideband suppressed carrier AM over FM signal;
- e) means combining the FM waveform with the double sideband suppressed carrier AM over FM signal to generate an in-band on-channel frequency modulation digital broadcast signal, wherein said in-band on-channel frequency modulation digital broadcast signal comprises said plurality of subchannel waveforms spectrally arrayed around said FM waveform, said subchannel waveforms slewing in frequency with said FM waveform;
- f) means transmitting said in-band on-channel frequency modulation digital broadcast signal;
- g) means receiving said in-band on-channel frequency modulation digital broadcast signals;
- h) means converting the received in-band on-channel frequency modulated digital broadcast signal to an intermediate frequency signal;
- i) means separating the intermediate frequency signal into a first, demodulated baseband FM, message and a second, DAB AM baseband, message;
- k) means producing from said second message a matched filtered waveform;
- and
- l) means demodulating the matched filtered waveform to generate a digital data signal.
9 more elements
Dependencies are inferred from the claim text.