System and method for selecting channels for short range transmissions to broadcast receivers

• US 20080076352A1
• Filed: 09/25/2006
• Published: 03/27/2008
• Est. Priority Date: 09/25/2006
• Status: Active Grant

• Current Assignee: Skyworks Solutions Incorporated
• Original Assignee: Silicon Laboratories Incorporated
• Inventors: Der, Lawrence
• Granted Patent: US 7,957,696 B2
• Time in Patent Office: Days
• US Class Current: 455/41.2
• CPC Class Codes: H04B 1/034 Portable transmitters
• CPC Class Codes: H04B 17/23 Indication means, e.g. displays, alarms, audible means

Abstract

Methods and systems for determining transmission channels for short range transmissions are disclosed. A transmitter provides short range transmission to a broadcast receiver configured to receive and tune channels within a signal spectrum. Channels within the broadcast signal spectrum are scanned, and an indication of received signal strength is obtained for each channel. The received signal strength indication (RSSI) can then be compared to a threshold power level that correlates to a signal level that the transmitter will be capable of overpowering based upon the transmission power of the transmitter. The scan results in an indication of one or more channels that have received signal strengths below the threshold power level of the transmitter.

Claims

1. A method of identifying transmission channels for short range broadcasts to broadcast receivers, comprising:

providing a transmitter configured to provide short range broadcasts to an external broadcast receiver configured to tune channels within a broadcast signal spectrum;

using a receiver to scan a plurality of channels within the broadcast signal spectrum;

determining for each channel a level of received signal strength for that channel;

comparing the received signal strength for each channel to a threshold power level, the threshold power level correlating to a transmit power for the transmitter;

identifying one or more channels that have received signal strengths below the threshold power level; and

outputting an indication these one or more channels.

2. The method of claim 1, wherein the receiver is configured to receive terrestrial audio broadcasts.

3. The method of claim 1, wherein the broadcast signal spectrum comprises an FM band.

4. The method of claim 1, further comprising communicating between the external broadcast receiver and the transmitter using one or more of the identified channels that have received signal strengths below the threshold power level.

5. The method of claim 1, further comprising providing a receiver and a transmitter integrated on the same integrated circuit.

6. The method of claim 5, further comprising communicating channel information from the integrated circuit to an external broadcast receiver.

7. The method of claim 6, wherein the receiver, the transmitter and the external broadcast receiver each are configured to be operable in an FM band.

8. The method of claim 1, further comprising adjusting transmit power for the transmitter to increase or decrease the threshold power level.

9. The method of claim 1, further comprising selecting a channel for short range broadcasts, using the selected channel for short range broadcasts, and monitoring the selected channel to determine changes in its receive signal strength.

10. The method of claim 9, further comprising repeating the using, determining, comparing and outputting steps if the receive signal strength of the selected channel goes above the threshold power level.

11. The method of claim 9, further comprising adjusting transmit power of for the transmitter in response to changes in the receive signal strength of the selected channel.

12. A system for providing short range broadcast to broadcast receivers, comprising:

a transmitter configured to provide short range broadcasts to a broadcast receiver configured to tune channels within a broadcast signal spectrum;

a receiver configured to receive and tune channels within the broadcast signal spectrum;

receive signal strength indication circuitry configured to determine a received signal strength for a channel tuned by the receiver; and

control circuitry coupled to the receive signal strength indication circuitry and configured to compare the received signal strength for each channel to a threshold power level value correlating to a transmit power for the transmitter and to output an indication of one or more channels that have received signal strengths below the threshold value.

13. The system of claim 12, wherein the receiver is configured to receive terrestrial audio broadcasts.

14. The system of claim 13, wherein the broadcast signal spectrum is FM band.

15. The system of claim 12, further comprising an external broadcast receiver and wherein the transmitter is configured to use one or more channels that have received signal strengths below the threshold power level to communicate with the external broadcast receiver.

16. The system of claim 12, wherein the receiver and the transmitter are integrated within the same integrated circuit.

17. The system of claim 16, further comprising an external audio system including a broadcast receiver.

18. The system of claim 17, wherein the receiver, the transmitter and the broadcast receiver each are configured to be operable in an FM band.

19. The system of claim 17, further comprising a connection between the transceiver and the external audio system configured to provide an indication of one or more channels having received signal strength below the threshold value.

20. The system of claim 19, wherein the external audio system is configured to select a channel to be used for short range transmissions.

21. The system of claim 12, wherein the transmit power for the transmitter is configured to be adjusted based upon the signal strength comparisons.