Apparatus and methods for finding and using available transmission frequencies
First Claim
1. A sound generation device comprising:
- an audio source to generate an audio signal;
a radio frequency (RF) transmitter, coupled to the audio source, to transmit an RF carrier signal modulated with the audio signal, the RF carrier signal having a specific carrier frequency; and
a channel locator controller to identify an available carrier frequency.
1 Assignment
0 Petitions
Accused Products
Abstract
A low-power radio frequency (RF) transmitter includes circuitry for finding unused transmission frequencies on a frequency band, such as an FM broadcast band, and to use an available frequency to broadcast a low-power audio signal to a sound reproduction device. In one embodiment, the sound reproduction device forms part of an entertainment system such as a vehicular stereo, home stereo, boom box, or RF headset. In one embodiment, the transmitter is operatively part of a sound generation device capable of generating and/or reproducing music or sound, such as an MP3 player or other portable entertainment device, personal digital assistant, electronic musical instrument, electronic toy, wireless microphone, or the like. The sound generation device can use an RF receiver or a geoposition source to identify an available transmission frequency. Also described are a sound generation system, a computer-readable medium, and various methods, including methods for finding and using available transmission frequencies.
146 Citations
33 Claims
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1. A sound generation device comprising:
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an audio source to generate an audio signal;
a radio frequency (RF) transmitter, coupled to the audio source, to transmit an RF carrier signal modulated with the audio signal, the RF carrier signal having a specific carrier frequency; and
a channel locator controller to identify an available carrier frequency. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A sound reproduction system comprising:
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a radio frequency (RF) receiver, including an RF tuner to tune the RF receiver to one of a plurality of RF channels;
an amplifier coupled to the RF receiver;
a sound transducer coupled to the amplifier; and
a channel selection circuit, coupled to the RF tuner, to receive a channel selection signal from an ancillary device, the channel selection signal to tune the RF tuner to one of the plurality of RF channels whose signal strength is below a predetermined minimum value. - View Dependent Claims (8, 9)
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10. A method of operating a radio frequency (RF) receiver comprising:
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determining whether a carrier is received at a first frequency; and
if so, marking the first frequency as unavailable and repeating the determining for a second frequency;
otherwise, marking the first frequency as available. - View Dependent Claims (11, 12, 13, 14, 15)
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16. A method of operating a radio frequency (RF) transceiver comprising:
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determining whether a carrier is received at a first frequency; and
if so, marking the first frequency as unavailable and repeating the determining for a second frequency;
otherwise, transmitting on the first frequency. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
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24. A method of operating a portable entertainment system comprising a radio frequency (RF) transmitter and a geoposition source, the method comprising:
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determining whether a geoposition of the portable entertainment system has changed;
if not, repeating the determining;
otherwise, obtaining a new geoposition from the geoposition source;
using the new geoposition to find an available transmission frequency; and
transmitting audio material from an audio source on the available transmission frequency. - View Dependent Claims (25, 26, 27)
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28. A method of operating a sound reproduction system comprising a radio frequency (RF) receiver, the method comprising:
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selecting an FM channel, within a broadcast band ranging from 87.7 to 107.9 megahertz, whose carrier signal strength is below a predetermined minimum value;
operating the RF receiver to receive audio material on the FM channel from an ancillary device;
amplifying the audio material using an amplifier coupled to the RF receiver; and
reproducing the audio material through a sound transducer coupled to the amplifier. - View Dependent Claims (29, 30)
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31. A computer-readable medium containing computer instructions for instructing a processor, the processor for use in a portable entertainment system comprising a radio frequency (RF) transmitter to transmit audio source material to a sound reproduction system over a transmission channel, wherein the instructions comprise:
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responding to a request for an available transmission channel;
receiving geoposition information; and
determining an available transmission channel based upon the geoposition information. - View Dependent Claims (32, 33)
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Specification