EP0372499A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Apparatus and method for providing digital audio in the FM broadcast band
Assignee: Arris Technology Inc
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Filing: 1989-12-05
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Granted: —
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Expires: 2009-12-05
Abstract
Abstract Method and apparatus are provided for transmitting, receiving, and reproducing digital audio signals as discrete carriers similar to standard FM broadcast signals. An audio signal is digitized using, for example, adaptive delta modulation techniques. Several channels of audio information, such as left and right stereo channels and a second audio program ("SAP") channel can all be digitized and incorporated onto the digital broadcast signal carrier. The digitized audio signal may be modulated using multiphase modulation of the carrier of an FM broadcast band signal. A plurality of audio channels may be digitized and transmitted over the airwaves, or over a cable transmission network. Channels of nondigitized audio channels may be interspersed with the digitized audio channels. Source material for the digitized audio channels may be provided to a cable headend over the cable transmission network outside the FM band, and rebroadcast over the cable transmission network in the FM band. Advantageously, an "extended" FM band between 72-120 MHz is employed to provide more channels than the "standard" FM band of 88-108 MHz.
Inventors
- 👤 Clyde Robbins
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 17:44
CPC Classifications
H; H04; H04H; H04H20/00; H04H20/65; H04H20/86; H04H20/95; H04H60/00; H04H60/09; H04H60/14
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
21 words
A method of broadcasting audio signals, comprising: digitizing audio source material; and transmitting the digitized source material in the FM band.
Claim 2
Independent Claim
21 words
A method of broadcasting audio signals, comprising: digitizing audio source material; and transmitting the digitized source material in the FM band.
Claim 3
Dependent Claim
31 words
A method according to claim 1, further comprising; digitizing a plurality of channels of audio source material; and transmitting the plurality of channels of digitized source material in the FM band.
Claim 4
Dependent Claim
16 words
A method according to claim 1 or 2, wherein the FM band is between 88-108 MHz.
Claim 5
Dependent Claim
16 words
A method according to claim 1 or 2, wherein the FM band is between 72-120 MHz.
Claim 6
Independent Claim
30 words
A method according to one of claims 2 to 4, wherein the plurality of channels of digitized audio source material are transmitted on alternate channel allocations within the FM band.
Claim 7
Independent Claim
23 words
A method according to one of claims 2 to 5, further comprising: transmitting channels of nondigitized audio source material in the FM band.
Claim 8
Dependent Claim
39 words
A method according to claim 6, wherein the several channels of digitized audio source material are transmitted on alternate channel allocations within the FM band, said alternate channel allocations interspersed with channel allocations for the nondigitized audio source material.
Claim 9
Independent Claim
23 words
A method according to one of the preceding claims, wherein the digitized audio source material is transmitted over a cable television transmission line.
Claim 10
Dependent Claim
42 words
A method according to claim 8, further comprising: providing for at least one station at least one channel of audio source material on the transmission line in a band outside of the FM band for digitizing and transmission in the FM band.
Claim 11
Dependent Claim
17 words
A method according to claim 9, wherein the band outside of the FM band is 5-30 MHz.
Claim 12
Dependent Claim
27 words
A method according to claim 9 or 10, wherein the at least one station also broadcasts over the airwaves at least one channel of audio source material.
Claim 13
Independent Claim
23 words
A method according to one of claims 9 to 11, wherein the audio source material is provided from the station in digital format.
Claim 14
Independent Claim
23 words
A method according to one of the preceding claims, wherein the digitized audio source material is transmitted in quadrature phase shift keyed format.
Claim 15
Independent Claim
18 words
A method according to one of claims 2 to 13, wherein a portion of the channels are encrypted.
Claim 16
Independent Claim
31 words
A method according to one of the preceding claims, further comprising: receiving the digitized audio source material; and decrypting the digitized audio source material and converting to analog form for listening.
Claim 17
Dependent Claim
55 words
Apparatus for receiving digitally transmitted audio signals comprising: means for tuning to signals in the FM broadcast band; means for detecting digitized audio source material contained in a selected one of said signals output from said tuning means; and digital demodulator means for processing the detected digitized source material to provide an audio output signal.
Claim 18
Dependent Claim
55 words
Apparatus for receiving digitally transmitted audio signals comprising: means for tuning to signals in the FM broadcast band; means for detecting digitized audio source material contained in a selected one of said signals output from said tuning means; and digital demodulator means for processing the detected digitized source material to provide an audio output signal.
Claim 19
Dependent Claim
43 words
Apparatus according to claim 16 further comprising: means for detecting nondigitized audio source material contained in a selected one of said signals output from said tuning means; and analog demodulator means for processing said nondigitized source material to provide an audio output signal.
Claim 20
Dependent Claim
60 words
Apparatus according to claim 17 further comprising: means for determining when a signal tuned by said tuning means contains digitized audio source material; and switch means responsive to said determining means for selectively outputting an audio output signal from said digital demodulator means or said analog demodulator means depending on whether a tuned signal contains digitized or nondigitized source material.
Claim 21
Dependent Claim
31 words
Apparatus according to one of claims 16 to 18 wherein said tuning means tunes to alternate channel allocations within the FM band to selectively receive interspersed digitized and nondigitized source material.
Claim 22
Dependent Claim
27 words
Apparatus according to one of claims 16 to 19 further comprising: means for coupling said tuning means to receive signals transmitted over a cable television transmission line.
Claim 23
Dependent Claim
29 words
Apparatus for broadcasting audio signals, comprising: means for digitizing audio source material; and means, coupled to said digitizing means, for transmitting the digitized source material in the FM band.
Claim 24
Dependent Claim
29 words
Apparatus for broadcasting audio signals, comprising: means for digitizing audio source material; and means, coupled to said digitizing means, for transmitting the digitized source material in the FM band.
Claim 25
Dependent Claim
34 words
Apparatus according to claim 21 further comprising: means for digitizing a plurality of channels of audio source material; and means for transmitting the plurality of channels of digitized source material in the FM band.
Claim 26
Dependent Claim
31 words
Apparatus according to claim 21 or 22 further comprising: means for transmitting channels of nondigitized audio source material in the FM band interspersed with said channels of digitized audio source material.
References Cited (Backward Citations)
No citation records indexed.
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