US5838799A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital sound broadcasting using a dedicated control channel
Assignee: Texas Instruments Inc
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Filing: 1995-05-26
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Granted: 1998-11-17
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Expires: 2015-05-26
Abstract
Abstract A method and apparatus for transmitting digital sound is disclosed. The method contemplates transmitting a digital radio signal (such as an FM band signal) over a plurality of sub-channels subject to some constraints on the digital signal power. A control sub-channel, sometimes referred to as an auxiliary overhead channel is used to transmit control information which is interpreted by the receiver to identify the location and potentially the mode of the digital signals.
Inventors
- 👤 John M. Cioffi
- 👤 John A. C. Bingham
- 👤 Mark P. Mallory
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:00
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/26; H04L27/2601; H04L27/2602; H04B; H04B1/00; H04B1/06; H04B1/16; H04B1/30; H04H; H04H20/00; H04H20/28; H04H20/30; H04J; H04J1/00; H04J1/02; H04J1/14; H04L5/00; H04L5/02; H04L5/023; H04H2201/00; H04H2201/10; H04H2201/18; H04H2201/183; H04H60/00; H04H60/68; H04H60/73; H04L27/2603
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
266 words
A method of transmitting digital sound by frequency modulation using carrier frequencies in an FM radio band of frequencies, said FM radio band of frequencies being organized into a plurality of FM radio band signal strength masks, each of said FM radio band signal strength masks having a central portion and two sidelobe portions, the method comprising the steps of: transmitting a discrete multi-tone digital FM band radio audio signal in parallel over a first plurality of sub-channels, said discrete multi-tone digital FM band radio audio signal representing a content of said digital sound, said first plurality of sub-channels representing a subset of available sub-channels within a first FM radio band signal strength mask of said FM radio band signal strength masks, said available sub-channels being located in one of said central portion of said first FM radio signal strength mask that is unoccupied by an analog audio signal and at least one of said two sidelobe portions of said first FM radio signal strength mask that is nonoverlapped by two immediately adjacent FM radio band signal strength masks of said plurality of FM radio band signal strength masks; and transmitting a control signal on a control sub-channel, said control sub-channel representing a sub-channel of said available sub-channels that is different from said first plurality of sub-channels, the control signal containing information for decoding the discrete multi-tone digital FM band radio signal upon reception by a receiver including information indicative of the number of sub-channels that carry the discrete multi-tone digital radio audio signal as well as their location in the FM radio band of frequencies.
Claim 2
Independent Claim
266 words
A method of transmitting digital sound by frequency modulation using carrier frequencies in an FM radio band of frequencies, said FM radio band of frequencies being organized into a plurality of FM radio band signal strength masks, each of said FM radio band signal strength masks having a central portion and two sidelobe portions, the method comprising the steps of: transmitting a discrete multi-tone digital FM band radio audio signal in parallel over a first plurality of sub-channels, said discrete multi-tone digital FM band radio audio signal representing a content of said digital sound, said first plurality of sub-channels representing a subset of available sub-channels within a first FM radio band signal strength mask of said FM radio band signal strength masks, said available sub-channels being located in one of said central portion of said first FM radio signal strength mask that is unoccupied by an analog audio signal and at least one of said two sidelobe portions of said first FM radio signal strength mask that is nonoverlapped by two immediately adjacent FM radio band signal strength masks of said plurality of FM radio band signal strength masks; and transmitting a control signal on a control sub-channel, said control sub-channel representing a sub-channel of said available sub-channels that is different from said first plurality of sub-channels, the control signal containing information for decoding the discrete multi-tone digital FM band radio signal upon reception by a receiver including information indicative of the number of sub-channels that carry the discrete multi-tone digital radio audio signal as well as their location in the FM radio band of frequencies.
Claim 3
Dependent Claim
23 words
A method as recited in claim 1 wherein the control signal is transmitted on a dedicated control sub-channel that carries only control information.
Claim 4
Dependent Claim
17 words
A method as recited in claim 2 wherein the control signal is multiplexed with a pilot signal.
Claim 5
Dependent Claim
20 words
A method as recited in claim 2 wherein a redundant control signal is transmitted on a second dedicated control sub-channel.
Claim 6
Dependent Claim
19 words
A method as recited in claim 1 wherein a redundant control signal is transmitted on a second control sub-channel.
Claim 7
Dependent Claim
44 words
A method as recited in claim 5 wherein the first control sub-channel is located at a frequency that is higher than a base carrier frequency and the second control sub-channel is located at a second frequency that is lower than the base carrier frequency.
Claim 8
Dependent Claim
20 words
A method as recited in claim 1 wherein a plurality of the sub-channels are used to transmit video data signals.
Claim 9
Dependent Claim
22 words
A method as recited in claim 1 wherein a plurality of the sub-channels are used to transmit bilingual broadcasts of a program.
Claim 10
Dependent Claim
21 words
A method as recited in claim 1 wherein a plurality of the sub-channels are used to transmit auxiliary digital data signals.
Claim 11
Dependent Claim
19 words
A method as recited in claim 1 wherein the control signal is transmitted as a continuous string of frames.
Claim 12
Dependent Claim
25 words
A method as recited in claim 10 wherein a signature identifying each frame as a portion of the control signal is transmitted with each frame.
Claim 13
Dependent Claim
29 words
A method as recited in claim 10 wherein each frame further includes a command that indicates a transmission mode which is in use to transmit the digital radio signal.
Claim 14
Dependent Claim
21 words
A method as recited in claim 1 wherein the receiver scans sub-channels within two sidelobe portions to locate the control sub-channel.
Claim 15
Independent Claim
147 words
A method of transmitting digital sound by frequency modulation using carrier frequencies in an FM band of frequencies, the method comprising the steps of: transmitting an analog FM radio signal over a single designated FCC approved FM channel having a signal strength mask for a single carrier with a pair of sidelobes; transmitting a discrete multi-tone digital FM band radio signal over a plurality of transmission sub-channels within the designated FCC approved FM signal strength mask wherein said plurality of transmission sub-channels being located on a sidelobe of said signal strength mask that is nonoverlapped by an immediately adjacent FCC approved FM channel; and transmitting a control signal on a control sub-channel, the control signal containing information for decoding the discrete multi-tone digital FM band radio signal upon reception by a receiver, the control sub-channel being located in one of the sidelobes of the signal strength mask.
Claim 16
Independent Claim
147 words
A method of transmitting digital sound by frequency modulation using carrier frequencies in an FM band of frequencies, the method comprising the steps of: transmitting an analog FM radio signal over a single designated FCC approved FM channel having a signal strength mask for a single carrier with a pair of sidelobes; transmitting a discrete multi-tone digital FM band radio signal over a plurality of transmission sub-channels within the designated FCC approved FM signal strength mask wherein said plurality of transmission sub-channels being located on a sidelobe of said signal strength mask that is nonoverlapped by an immediately adjacent FCC approved FM channel; and transmitting a control signal on a control sub-channel, the control signal containing information for decoding the discrete multi-tone digital FM band radio signal upon reception by a receiver, the control sub-channel being located in one of the sidelobes of the signal strength mask.
Claim 17
Dependent Claim
24 words
A method as recited in claim 14 wherein a plurality of the transmission sub-channels, are used to transmit compact disc quality digital audio signals.
Claim 18
Dependent Claim
30 words
A method as recited in claim 14 wherein carrier frequencies for the plurality of transmission sub-channels are chosen to avoid a principle frequency band occupied by the analog FM signal.
Claim 19
Dependent Claim
29 words
A method as recited in claim 16 wherein a plurality of the sub-channels are used to transmit digital audio data signals that correspond to the analog FM radio signal.
Claim 20
Independent Claim
270 words
A method of transmitting digital sound by frequency modulation using carrier frequencies in an FM band of frequencies, said FM band of frequencies being organized into a plurality of FM radio band signal strength masks, each of said FM radio band signal strength masks having a central portion and two sidelobe portions, the method comprising the steps of: transmitting a discrete multi-tone digital FM band radio audio signal in parallel over a first plurality of sub-channels, said discrete multi-tone digital FM band radio audio signal representing a content of said digital sound, said first plurality of sub-channels representing a subset of available sub-channels within a first FM radio band signal strength mask of said FM radio band signal strength masks said available sub-channels being located in one of said central portion of said first FM radio signal strength mask that is unoccupied by an analog audio signal and at least one of said two sidelobe portions of said first FM radio signal strength mask that is nonoverlapped by two immediately adjacent FM radio band signal strength masks of said plurality of FM radio band signal strength masks, and transmitting control information on a control signal over a control sub-channel, said control sub-channel representing a sub-channel of said available sub-channels that is different from said first plurality of sub-channels, the control information being transmitted as a continuous string of frames wherein each frame includes a signature identifying the frame as a portion of the control signal and control data to enable a receiver to identify the plurality of sub-channels used to carry the discrete multi-tone digital FM band radio audio signal.
Claim 21
Independent Claim
270 words
A method of transmitting digital sound by frequency modulation using carrier frequencies in an FM band of frequencies, said FM band of frequencies being organized into a plurality of FM radio band signal strength masks, each of said FM radio band signal strength masks having a central portion and two sidelobe portions, the method comprising the steps of: transmitting a discrete multi-tone digital FM band radio audio signal in parallel over a first plurality of sub-channels, said discrete multi-tone digital FM band radio audio signal representing a content of said digital sound, said first plurality of sub-channels representing a subset of available sub-channels within a first FM radio band signal strength mask of said FM radio band signal strength masks said available sub-channels being located in one of said central portion of said first FM radio signal strength mask that is unoccupied by an analog audio signal and at least one of said two sidelobe portions of said first FM radio signal strength mask that is nonoverlapped by two immediately adjacent FM radio band signal strength masks of said plurality of FM radio band signal strength masks, and transmitting control information on a control signal over a control sub-channel, said control sub-channel representing a sub-channel of said available sub-channels that is different from said first plurality of sub-channels, the control information being transmitted as a continuous string of frames wherein each frame includes a signature identifying the frame as a portion of the control signal and control data to enable a receiver to identify the plurality of sub-channels used to carry the discrete multi-tone digital FM band radio audio signal.
Claim 22
Dependent Claim
29 words
A method as recited in claim 18 wherein each frame further includes a command that indicates a transmission mode which is in use to transmit the digital radio signal.
Claim 23
Dependent Claim
22 words
A method as recited in claim 19 wherein the control sub-channel is a dedicated control sub-channel that carries only the control information.
Claim 24
Dependent Claim
38 words
A method as recited in claim 18 wherein the control signal indicates the number of sub-channels that carry the digital radio signal and an indicia that identifies a location of a first one of the plurality of sub-channels.
Claim 25
Dependent Claim
165 words
A digital radio signal receiver comprising: means for receiving a discrete multi-tone digital radio signal in the FM frequency band, the digital radio audio signal being transmitted in parallel using a plurality of subcarriers each having an associated sub-channel within a designated portion of a FM radio band signal strength mask having a central portion and two sidelobe portions, said designated portion being one of said central portion that is unoccupied by an analog audio signal and one of said two sidelobe portions that is nonoverlapped by two immediately adjacent FM radio band signal strength masks of said FM frequency band; means for interpreting a control signal received on at least one control sub-channel, wherein the control signal provides information indicative of frequency bands used to transmit the digital radio audio signal and the number of sub-channels used to carry the digital radio audio signal; and means for decoding the digital radio audio signal based upon the information interpreted by the control signal interpreting means.
Claim 26
Dependent Claim
165 words
A digital radio signal receiver comprising: means for receiving a discrete multi-tone digital radio signal in the FM frequency band, the digital radio audio signal being transmitted in parallel using a plurality of subcarriers each having an associated sub-channel within a designated portion of a FM radio band signal strength mask having a central portion and two sidelobe portions, said designated portion being one of said central portion that is unoccupied by an analog audio signal and one of said two sidelobe portions that is nonoverlapped by two immediately adjacent FM radio band signal strength masks of said FM frequency band; means for interpreting a control signal received on at least one control sub-channel, wherein the control signal provides information indicative of frequency bands used to transmit the digital radio audio signal and the number of sub-channels used to carry the digital radio audio signal; and means for decoding the digital radio audio signal based upon the information interpreted by the control signal interpreting means.
Claim 27
Dependent Claim
49 words
A digital radio signal receiver as received in claim 22 wherein the control signal interpreting means includes a controller that identifies a control sub-channel that contains the control signal and determines the frequency bands that carry the digital radio signal based on the information included in the control signal.
Claim 28
Dependent Claim
18 words
A digital radio signal receiver as recited in claim 22 wherein the receiving means includes an RF demodulator.
Claim 29
Dependent Claim
31 words
A digital radio signal receiver as recited in claim 22 wherein the decoding means includes a Fast Fourier Transform (FFT) decoder, a differential PSK decoder and a forward error correction decoder.
Claim 30
Dependent Claim
155 words
A digital radio signal transmitter comprising: encoding means for encoding a digital audio signal into a compressed discrete multi-tone signal to be transmitted as part of a multi-carrier signal transmitted in parallel over a plurality of sub-channels within a designated portion of a FM radio band signal strength mask having a central portion and two sidelobe portions, said designated portion being one of a central portion that is unoccupied by an analog audio signal and a sidelobe portion that is nonoverlapped by two immediately adjacent stations, wherein each sub-channel having a designated frequency band; means for applying a control signal to a control sub-channel having a designated frequency band in the FM radio frequency band, the control signal providing information indicative of the frequency bands used to transmit the compressed digital signal; and means for transmitting the discrete multi-tone digital signal and the control signal as a radio signal in the FM radio frequency band.
Claim 31
Dependent Claim
155 words
A digital radio signal transmitter comprising: encoding means for encoding a digital audio signal into a compressed discrete multi-tone signal to be transmitted as part of a multi-carrier signal transmitted in parallel over a plurality of sub-channels within a designated portion of a FM radio band signal strength mask having a central portion and two sidelobe portions, said designated portion being one of a central portion that is unoccupied by an analog audio signal and a sidelobe portion that is nonoverlapped by two immediately adjacent stations, wherein each sub-channel having a designated frequency band; means for applying a control signal to a control sub-channel having a designated frequency band in the FM radio frequency band, the control signal providing information indicative of the frequency bands used to transmit the compressed digital signal; and means for transmitting the discrete multi-tone digital signal and the control signal as a radio signal in the FM radio frequency band.
Claim 32
Dependent Claim
25 words
A digital radio signal transmitter as recited in claim 26 wherein the control signal applying means applies the control signal to a dedicated control sub-channel.
Claim 33
Dependent Claim
18 words
A digital radio signal transmitter as recited in claim 26 wherein the transmitting means includes an RF modulator.
Claim 34
Dependent Claim
32 words
A digital radio signal transmitter as recited in claim 26 wherein the encoding means includes a forward error correction encoder, a differential PSK decoder and an inverse fast Fourier transform (IFFT) encoder.
Claim 35
Independent Claim
263 words
A method of transmitting digital sound by frequency modulation using carrier frequencies in an FM radio band of frequencies, said FM radio band of frequencies being organized into a plurality of FM radio band signal strength masks, each of said FM radio band signal strength masks having a central portion and two sidelobe portions, the method comprising the steps of: transmitting a discrete multi-tone digital FM band radio signal in parallel over a first plurality of sub-channels, said discrete multi-tone digital FM band radio signal representing a content of said digital sound, said first plurality of sub-channels representing a subset of available sub-channels within a first FM radio band signal strength mask of said FM radio band signal strength masks, said available sub-channels being located in one of said central portion of said first FM radio signal strength mask that is unoccupied by an analog audio signal and at least one of said two sidelobe portions of said first FM radio signal strength mask that is nonoverlapped by two immediately adjacent FM radio band signal strength masks of said plurality of FM radio band signal strength masks; and transmitting a control signal on a control sub-channel, said control sub-channel representing a sub-channel of said available sub-channels that is different from said first plurality of sub-channels, the control signal containing information for decoding the discrete multi-tone digital FM band radio signal upon reception by a receiver including information indicative of the number of sub-channels that carry the discrete multi-tone digital radio signal as well as their location in the FM radio band of frequencies.
Claim 36
Independent Claim
263 words
A method of transmitting digital sound by frequency modulation using carrier frequencies in an FM radio band of frequencies, said FM radio band of frequencies being organized into a plurality of FM radio band signal strength masks, each of said FM radio band signal strength masks having a central portion and two sidelobe portions, the method comprising the steps of: transmitting a discrete multi-tone digital FM band radio signal in parallel over a first plurality of sub-channels, said discrete multi-tone digital FM band radio signal representing a content of said digital sound, said first plurality of sub-channels representing a subset of available sub-channels within a first FM radio band signal strength mask of said FM radio band signal strength masks, said available sub-channels being located in one of said central portion of said first FM radio signal strength mask that is unoccupied by an analog audio signal and at least one of said two sidelobe portions of said first FM radio signal strength mask that is nonoverlapped by two immediately adjacent FM radio band signal strength masks of said plurality of FM radio band signal strength masks; and transmitting a control signal on a control sub-channel, said control sub-channel representing a sub-channel of said available sub-channels that is different from said first plurality of sub-channels, the control signal containing information for decoding the discrete multi-tone digital FM band radio signal upon reception by a receiver including information indicative of the number of sub-channels that carry the discrete multi-tone digital radio signal as well as their location in the FM radio band of frequencies.
Claim 37
Independent Claim
267 words
A method of transmitting digital sound by frequency modulation using carrier frequencies in an FM band of frequencies, said FM band of frequencies being organized into a plurality of FM radio band signal strength masks, each of said FM radio band signal strength masks having a central portion and two sidelobe portions, the method comprising the steps of: transmitting a discrete multi-tone digital FM band radio signal in parallel over a first plurality of sub-channels, said discrete multi-tone digital FM band radio signal representing a content of said digital sound, said first plurality of sub-channels representing a subset of available sub-channels within a first FM radio band signal strength mask of said FM radio band signal strength masks said available sub-channels being located in one of said central portion of said first FM radio signal strength mask that is unoccupied by an analog audio signal and at least one of said two sidelobe portions of said first FM radio signal strength mask that is nonoverlapped by two immediately adjacent FM radio band signal strength masks of said plurality of FM radio band signal strength masks; and transmitting control information on a control signal over a control sub-channel, said control sub-channel representing a sub-channel of said available sub-channels that is different from said first plurality of sub-channels, the control information being transmitted as a continuous string of frames wherein each frame includes a signature identifying the frame as a portion of the control signal and control data to enable a receiver to identify the plurality of sub-channels used to carry the discrete multi-tone digital FM band radio signal.
Claim 38
Independent Claim
267 words
A method of transmitting digital sound by frequency modulation using carrier frequencies in an FM band of frequencies, said FM band of frequencies being organized into a plurality of FM radio band signal strength masks, each of said FM radio band signal strength masks having a central portion and two sidelobe portions, the method comprising the steps of: transmitting a discrete multi-tone digital FM band radio signal in parallel over a first plurality of sub-channels, said discrete multi-tone digital FM band radio signal representing a content of said digital sound, said first plurality of sub-channels representing a subset of available sub-channels within a first FM radio band signal strength mask of said FM radio band signal strength masks said available sub-channels being located in one of said central portion of said first FM radio signal strength mask that is unoccupied by an analog audio signal and at least one of said two sidelobe portions of said first FM radio signal strength mask that is nonoverlapped by two immediately adjacent FM radio band signal strength masks of said plurality of FM radio band signal strength masks; and transmitting control information on a control signal over a control sub-channel, said control sub-channel representing a sub-channel of said available sub-channels that is different from said first plurality of sub-channels, the control information being transmitted as a continuous string of frames wherein each frame includes a signature identifying the frame as a portion of the control signal and control data to enable a receiver to identify the plurality of sub-channels used to carry the discrete multi-tone digital FM band radio signal.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-11-16 | 2002-05-18 | 2002-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-16 | 2006-05-18 | 2006-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-16 | 2010-05-18 | 2010-11-17 | $7700.00 | Window Closed / Lapsed |