Facilitating reuse of frequencies by unlicensed cognitive devices

• US 20070202867A1
• Filed: 02/24/2006
• Published: 08/30/2007
• Est. Priority Date: 02/24/2006
• Status: Abandoned Application

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Schiffer, Jeffrey, Waltho, Alan, Leeper, David, Rogers, Christopher
• Application Number:
  US11/361,226
• Publication Number:
  US 20070202867A1
• Time in Patent Office: Days
• US Class Current: 455/423
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 52/16 Deriving transmission power values from another channel

Abstract

A wireless device incorporates decentralized spectrum management to dynamically control a power level for each channel in a transmission spectrum. The decentralized spectrum management uses a common reference signal received from a TV station to select a channel and coordinate the transmitter power to mitigate interference. The decentralized spectrum management ensures that the propagation loss between the desired and interfering transmitters exceeds a desired power ratio in order to facilitate frequency reuse on a non-interfering basis.

Claims

1. A wireless device, comprising:

a cognitive radio to determine that a first channel is not in use; and

a characterization block in the cognitive radio to characterize two adjacent channels where one of the adjacent channels receives a reference signal that determines a power level used by the cognitive radio to transmit on the first channel.

2. The wireless device of claim 1 wherein the reference signal is an Ultra High Frequency (UHF) signal received from a TV station.

3. The wireless device of claim 2 wherein the characterization block characterizes the two adjacent channels to select the adjacent channel with the lowest received power.

4. The wireless device of claim 3 wherein the adjacent channel with the lowest received power corresponds to the adjacent channel that receives the UHF signal.

5. A wireless device comprising:

a transceiver to monitor and find a first channel not broadcasting a Ultra High Frequency (UHF) signal; and

a characterization block to characterize the first channel and at least one adjacent channel that receives the UHF signal that is used to set a power level used by the wireless device for transmission on the first channel.

6. The wireless device of claim 5 wherein the wireless device is an unlicensed wireless device.

7. The wireless device of claim 5 wherein the characterization block calculates power ratios for the first channel and the at least one adjacent channel to compare a predetermined channel requirement.

11. The wireless device of claim 7 wherein the signal power in the adjacent channel is used to set a transmit power for the wireless device.

8. A wireless device comprising:

first and second antenna coupled to a transceiver; and

a spectrum management circuit coupled to at least one of the first and second antenna to increment a channel number to locate a first channel unoccupied by a TV station.

9. The wireless device of claim 8 wherein the spectrum management circuit sets a first channel power level so that the adjacent channel receives a signal from the TV station.

10. The wireless device of claim 9 wherein the spectrum management circuit dynamically monitors and characterizes the first channel and the adjacent channel to determine signal powers.

12. A wireless device comprising:

an antenna coupled to a transceiver; and

a spectrum management circuit coupled to the antenna to locate a licensed Radio Frequency (RF) broadcast channel that is selected as an adjacent channel to prevent the wireless device from using the adjacent channel for communications.

13. The wireless device of claim 12 wherein the licensed RF broadcast channel is a Very High Frequency (VHF) channel.

14. The wireless device of claim 12 wherein the licensed RF broadcast channel is a Ultra High Frequency (UHF) channel.

15. The wireless device of claim 12 wherein the licensed RF broadcast channel is a Frequency Modulation (FM) channel.

16. The wireless device of claim 12 wherein the licensed RF broadcast channel is an Amplitude Modulation (AM) channel.

17. The wireless device of claim 12 wherein the licensed RF broadcast channel is a WiMax channel.

18. A method of providing spectrum management in a wireless device, comprising:

investigating, in the wireless device, received channel frequencies to determine an unoccupied channel;

selecting the unoccupied channel as a reusable channel;

measuring a power in the reusable channel and a power in the channels adjacent to the reusable channel; and

comparing power in the reusable channel to a predetermined power value.

19. The method of claim 18 wherein comparing power further includes comparing the power in the reusable channel to a predetermined power value which corresponds to a Signal-to-Noise Ratio (SNR) value for proper operation of a modulation scheme.

20. The method of claim 18 wherein investigating received channel frequencies further includes setting a channel to receive Ultra High Frequency (UHF) signals generated by a TV station.

21. The method of claim 18 further comprising:

incrementing a channel number to determine the unoccupied channel.

22. A method comprising:

determining that a channel is currently unoccupied; and

using an Ultra High Frequency (UHF) signal received in an adjacent channel of a wireless device to prevent the wireless device from selecting the adjacent channel for communications.

23. The method of claim 22 wherein using a UHF signal received in an adjacent channel of a wireless device further includes using an unlicensed wireless device.

24. The method of claim 22 further including:

characterizing the channel and the adjacent channel that receive the UHF signal to determine power levels.

25. The method of claim 24 further including:

setting a power level used by the wireless device for transmission on the first channel in accordance with the power level in the adjacent channel.

26. The method of claim 25 further including:

calculating power ratios for the channel and the adjacent channel to compare with a predetermined channel requirement.