Method and apparatus for dynamic channel selection in wireless modems

• US 20030181211A1
• Filed: 03/19/2002
• Published: 09/25/2003
• Est. Priority Date: 03/19/2002
• Status: Abandoned Application

• Current Assignee: M2 Networks, Inc.
• Original Assignee: M2 Networks, Inc.
• Inventors: Connors, Dennis P., Crawford, James A., Poojary, Neeraj, Razavilar, Javad
• Application Number:
  US10/101,891
• Publication Number:
  US 20030181211A1
• Time in Patent Office: Days
• US Class Current: 455/450
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 36/06 Reselecting a communication resource in the serving access point
• CPC Class Codes: H04W 36/20 for optimising the interference level

Abstract

A dynamic channel selection algorithm for a communication system including the steps of determining a channel metric indicative of a level of interference for a plurality of available channels; sorting the plurality of available channels according to their channel metrics; determining whether co-channel signaling is present on a available channel having a lowest channel metric; and selecting one of the available channels based upon whether the co-channel signaling is present on the available channel having the lowest channel metric. In variations, selection of an available channel is based upon whether co-channel signaling is present on available channels other than the available channel having a lower channel metric, and a difference between channel metrics of the available channel having the lowest channel metric and available channels having higher channel metrics.

Claims

1. A method for selecting between available channels comprising:

determining a channel metric corresponding to measurements taken at a receiver for each of a plurality of available channels, the channel metric indicative of a level of interference in each of the plurality of available channels;

sorting the plurality of available channels according to their respective channel metric;

determining whether co-channel signaling is present on an available channel having a lowest channel metric of the plurality of available channels; and

selecting one of the plurality of available channels based upon at least the determining whether the co-channel signaling is present on the available channel having the lowest channel metric.

2. The method of claim 1 wherein the step of determining whether the co-channel signaling is present on the available channel having the lowest channel metric comprises determining whether a preamble is present on the available channel having the lowest channel metric.

3. The method of claim 1 further comprising:

comparing, in the event that the co-channel signaling is present on the available channel having the lowest channel metric, the channel metric of the available channel having the lowest channel metric with a channel metric of an available channel having a higher channel metric;

wherein the step of selecting comprises selecting the one of the plurality of available channels based upon a difference between the channel metric of the available channel having the lowest channel metric and the channel metric of the available channel having the higher channel metric.

4. The method of claim 3 further comprising:

determining whether co-channel signaling is present on the available channel having a higher channel metric;

wherein the step of selecting comprises selecting the one of the plurality of available channels based upon whether the co-channel signaling is detected on the available channel having the higher channel metric.

5. The method of claim 4 wherein the step of determining whether the co-channel signaling is present on the available channel having the higher channel metric comprises determining whether a preamble is present on the available channel having the higher channel metric.

6. The method of claim 1 further comprising:

determining, in the event the co-channel signaling is present on the available channel having the lowest channel metric, whether co-channel signaling is present on an available channel having a higher channel metric;

wherein the step of selecting comprises selecting the one of the plurality of available channels based upon whether the co-channel signaling is detected on the available channel having the higher channel metric.

7. The method of claim 6 wherein the step of determining whether the co-channel signaling is present on the available channel having the higher channel metric comprises determining whether a preamble is present on the available channel having the higher channel metric.

8. The method of claim 1 comprising:

re-determining, in the event the available channel having the lowest channel metric is greater than a threshold, another channel metric for each of the plurality of available channels.

9. The method of claim 1 wherein the step of determining the channel metric for each of the plurality of available channels comprises:

receiving a plurality of received signal strength measurements corresponding to L discrete received signal strength measurements taken at an antenna of the receiver within a time period of a measurement window for each of the plurality of available channels;

retaining a quantity of M of the plurality of received signal strength measurements for each of the plurality of available channels, wherein the quantity M is a value up to 25% of L; and

assigning the channel metric denoted by m_i to each of the plurality of available channels equal to;

$m_i=\frac{1}{M}<br><br>\underset{j=1}{\overset{M}{\sum <br><br>}}<br><br>\mathrm{ARRSI}<br><br>\left[j\right]<br><br>\text{\hspace{1em}<br><br>}<br><br>i=1,2,\text{\hspace{1em}<br><br>}<br><br>\mathrm{\dots <br><br>}<br><br>\text{\hspace{1em}<br><br>},I$

where ARRSI[j] is one of the received signal strength measurements, j is a received signal strength measurement index, i is an available channel index, and where i=1,2,3 . . . I, where I is a quantity of the plurality of available channels.

10. The method of claim 9 wherein the step of retaining comprises retaining the quantity of M received signal strength measurements from a set of the highest of the plurality of received signal strength measurements for each of the plurality of available channels.

11. A channel selection device for a communication terminal of a communication system comprising:

a dynamic channel selection module configured to perform the following steps;

determining a channel metric corresponding to measurements taken at a receiver for each of a plurality of available channels, the channel metric indicative of a level of interference in each of the plurality of available channels;

sorting the plurality of available channels according to their respective channel metric;

obtaining an indication whether co-channel signaling is present on an available channel having a lowest channel metric of the plurality of available channels; and

selecting one of the plurality of available channels based upon at least the determining whether the co-channel signaling is present on the available channel having the lowest channel metric.

12. The device of claim 11 further comprising an integrated circuit device, the dynamic channel selection module implemented within the integrated circuit device.

13. The channel selection device of claim 11 wherein the dynamic channel selection module is additionally configured to perform the following step:

comparing, in the event that the co-channel signaling is present on the available channel having the lowest channel metric, the channel metric of the available channel having the lowest channel metric with a channel metric of an available channel having a higher channel metric;

wherein the step of selecting comprises selecting the one of the available channels based upon the difference between the channel metric of the available channel having the lowest channel metric and the channel metric of available the available channel having the higher channel metric.

14. The channel selection device of claim 13 wherein the dynamic channel selection module is additionally configured to perform the following step:

obtaining an indication whether co-channel signaling is present on the available channel having a higher channel metric;

wherein the step of selecting comprises selecting the one of the available channels based upon whether the co-channel signaling is detected on the available channel having the higher channel metric.

15. The channel selection device of claim 11 wherein the dynamic channel selection module is additionally configured to perform the following step:

determining, in the event that the co-channel signaling is present on the available channel having the lowest channel metric, whether co-channel signaling is present on the available channel having the higher channel metric;

wherein the step of selecting comprises selecting the one of the available channels based upon whether the co-channel signaling is detected on the available channel having the higher channel metric.

16. A channel selection device for a communication terminal of a communication system comprising:

means for determining a channel metric corresponding to measurements taken at a receiver for each of a plurality of available channels, the channel metric indicative of a level of interference in each of the plurality of available channels;

means for sorting the plurality of available channels according to their respective channel metric;

means for obtaining an indication whether co-channel signaling is present on an available channel having a lowest channel metric of the plurality of available channels; and

means for selecting one of the plurality of available channels based upon at least the determining whether the co-channel signaling is present on the available channel having the lowest channel metric.

17. The device of claim 16 further comprising:

means for comparing, in the event that the co-channel signaling is present on the available channel having the lowest channel metric, the channel metric of the available channel having the lowest channel metric with a channel metric of an available channel having a higher channel metric;

wherein the means for selecting comprises selecting the one of the plurality of available channels based upon a difference between the channel metric of the available channel having the lowest channel metric and the channel metric of the available channel having the higher channel metric.

18. The device of claim 17 further comprising

means for determining whether co-channel signaling is present on the available channel having a higher channel metric;

wherein the means for selecting comprises means for selecting the one of the available channels based upon whether the co-channel signaling is detected on the available channel having a higher channel metric.

19. The device of claim 16 further comprising:

means for determining whether co-channel signaling is present on an available channel having a higher channel metric;

wherein the means for selecting comprises means for selecting the one of the available channels based upon whether the co-channel signaling is detected on the available channel having the higher channel metric.

20. The device of claim 16 further comprising:

means for receiving a plurality of received signal strength measurements corresponding to L discrete received signal strength measurements taken at an antenna of the receiver within a time period of a measurement window for each of the plurality of available channels;

means for retaining a quantity of M of the plurality of received signal strength measurements for each of the plurality of available channels, wherein the quantity M is a value up to 25% of L; and

means for assigning the channel metric denoted by m_i to each of the plurality of available channels equal to;

$m_i=\frac{1}{M}<br><br>\underset{j=1}{\overset{M}{\sum <br><br>}}<br><br>\mathrm{ARRSI}<br><br>\left[j\right]<br><br>\text{\hspace{1em}<br><br>}<br><br>i=1,2,\text{\hspace{1em}<br><br>}<br><br>\mathrm{\dots <br><br>}<br><br>\text{\hspace{1em}<br><br>},I$

where ARRSI[j] is one of the received signal strength measurements, j is a received strength measurement index, i is an available channel index, and where i=1,2,3 . . . I, where I is a quantity of the plurality of available channels.

21. The method of claim 20 wherein the means for retaining comprises means for retaining the quantity of M received signal strength measurements from a set of the highest of the plurality of received signal strength measurements for each of the plurality of available channels.

22. A method for selecting between available channels comprising:

receiving a plurality of received signal strength measurements corresponding to L discrete received signal strength measurements taken at an antenna within a time period of a measurement window for each of a plurality of available channels;

retaining a quantity of M of the plurality of received signal strength measurements for each of the plurality of available channels, wherein the quantity M is a value up to 25% of L; and

assigning a channel metric denoted by m_i to each of the plurality of available channels equal to;

$m_i=\frac{1}{M}<br><br>\underset{j=1}{\overset{M}{\sum <br><br>}}<br><br>\mathrm{ARRSI}<br><br>\left[j\right]<br><br>\text{\hspace{1em}<br><br>}<br><br>i=1,2,\text{\hspace{1em}<br><br>}<br><br>\mathrm{\dots <br><br>}<br><br>\text{\hspace{1em}<br><br>},I$

where ARRSI[j] is one of the M received signal strength measurements, j is a received signal strength measurement index, i is an available channel index, and where i=1,2,3 . . . I, where I is a quantity of the plurality of available channels.

23. The method of claim 22 wherein the retaining step comprises retaining a quantity of M largest of the plurality of received signal strength measurements for each of the plurality of available channels.