Apparatus and methods for finding and using available transmission frequencies

• US 20030036357A1
• Filed: 08/17/2001
• Published: 02/20/2003
• Est. Priority Date: 08/17/2001
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: McGowan, Steven B.
• Granted Patent: US 7,512,380 B2
• Time in Patent Office: Days
• US Class Current: 455/62
• CPC Class Codes: H03J 1/0066 with means for analysing the received signal strength H03J1/0083 takes precedence
• CPC Class Codes: H03J 1/0091 provided with means for scanning over a band of frequencies H03J1/0058 takes precedence
• CPC Class Codes: H04B 1/034 Portable transmitters
• CPC Class Codes: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones

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.

Claims

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.

2. The sound generation device recited in claim 1, wherein the channel locator controller comprises:

an RF receiver, coupled to the RF transmitter, to receive RF signals having different carrier frequencies; and

a channel locator circuit, coupled to the RF receiver, to identify a carrier frequency below a minimum signal strength.

3. The sound generation device recited in claim 1, wherein the channel locator controller comprises:

a stored program digital computer, the computer to store a database of available carrier frequencies arranged by geoposition; and

a geoposition source coupled to the stored program digital computer to provide a geoposition to the stored program digital computer.

4. The sound generation device recited in claim 1, wherein the geoposition source comprises an element from the group comprising a cellular phone, a GPS receiver, a geoposition programming device, a data entry device, and a programmable read only memory.

5. The sound generation device recited in claim 1, wherein the sound generation device further comprises:

a channel selection circuit, coupled to the RF transmitter, to select an available carrier frequency on which to transmit the RF carrier signal.

6. The sound generation device recited in claim 1, wherein the sound generation device comprises equipment from the group comprising an MP3 player, a CD player, a mini-disk player, a micro-disk player, a DVD player, a cassette tape player, a radio, a cellular phone, a handheld computer, a portable computer, a television, a video player, a personal digital assistant, an electronic musical instrument, an electronic toy, and a wireless microphone.

7. A sound reproduction system comprising:

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.

8. The sound reproduction system recited in claim 7, wherein the sound reproduction system is from the group comprising a vehicular entertainment system, a home entertainment system, and a portable entertainment system.

9. The sound reproduction system recited in claim 7, wherein the ancillary device is from the group comprising an MP3 player, a CD player, a mini-disk player, a micro-disk player, a DVD player, a cassette tape player, a radio, a cellular phone, a handheld computer, a portable computer, a television, a video player, an electronic musical instrument, an electronic toy, and a wireless microphone.

10. A method of operating a radio frequency (RF) receiver comprising:

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.

11. The method recited in claim 10 and further comprising:

displaying at least one available frequency.

12. The method recited in claim 10 and further comprising:

selecting at least one available frequency.

13. The method recited in claim 10 and further comprising:

evaluating available frequencies; and

marking an optimum available frequency from the available frequencies.

14. The method recited in claim 13 and further comprising:

displaying the optimum available frequency.

15. The method recited in claim 13 and further comprising:

selecting the optimum available frequency.

16. A method of operating a radio frequency (RF) transceiver comprising:

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.

17. The method recited in claim 16 and further comprising:

displaying the first frequency.

18. The method recited in claim 16, wherein the RF transceiver comprises an audio source, and wherein in transmitting the audio source is transmitted on the first frequency.

19. The method recited in claim 18, wherein the audio source comprises prerecorded audio material.

20. The method recited in claim 18, and further comprising:

transmitting a channel selection signal before transmitting the audio source.

21. The method recited in claim 18, and further comprising:

between determining and transmitting, repeating the determining until at least two available frequencies are located;

evaluating the at least two available frequencies; and

marking an optimum available frequency from the at least two available frequencies.

22. The method recited in claim 21 and further comprising:

displaying the optimum available frequency.

23. The method recited in claim 21, and further comprising:

transmitting a channel selection signal comprising the optimum available frequency before transmitting the audio source.

24. A method of operating a portable entertainment system comprising a radio frequency (RF) transmitter and a geoposition source, the method comprising:

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.

25. The method recited in claim 24, wherein the geoposition source is obtained from an element from the group comprising a cellular phone, a GPS receiver, a keyboard, a set of switches, and a programmable read only memory.

26. The method recited in claim 24 and further comprising:

displaying the available transmission frequency.

27. The method recited in claim 24 and further comprising:

transmitting a channel selection signal comprising the available transmission frequency before transmitting the audio material.

28. A method of operating a sound reproduction system comprising a radio frequency (RF) receiver, the method comprising:

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.

29. The method recited in claim 28, wherein selecting is performed upon receipt of a channel selection signal from the ancillary device.

30. The method recited in claim 29, wherein the channel selection signal is received by the RF receiver, prior to the audio material, via a transmission medium from the group comprising a light-beam transmission, an RF transmission outside the broadcast band, or a wireline transmission.

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:

responding to a request for an available transmission channel;

receiving geoposition information; and

determining an available transmission channel based upon the geoposition information.

32. The computer-readable medium recited in claim 31, wherein receiving comprises processing data originating from a device from the group comprising a cellular phone, a GPS receiver, a keyboard, a set of switches, and a programmable read only memory.

33. The computer-readable medium recited in claim 31, wherein determining comprises finding an available transmission channel in a database using the geoposition information.