System for allocating channels in a multi-radio wireless LAN array

• US 8,798,069 B2
• Filed: 01/02/2013
• Issued: 08/05/2014
• Est. Priority Date: 05/13/2008
• Status: Active Grant

• Current Assignee: Cambium Networks Limited (Cambium Networks Corporation)
• Original Assignee: Xirrus Incorporated
• Inventors: Gates, Dirk Ion, Mathews, James Kirk
• Primary Examiner(s): KHAJURIA, SHRIPAL K
• Application Number:
  US13/732,841
• Publication Number:
  US 20130343210A1
• Time in Patent Office: 580 Days
• Field of Search: 370/392
• US Class Current: 370/392
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

A channel allocation system for allocating channels in a frequency band to a plurality of radios in close proximity so as to minimize co-channel interference. One method for allocating channels involves initially tuning each of the plurality of radios to the same one of the plurality of channels. All of the radios then receive signals from whatever sources and a signal score is determined for each radio. The radios are then tuned to another one of the plurality of channels. The steps of receiving a signal and determining a signal score for each radio are repeated for each of the remaining channels until all channels have been used. The signal scores are then tested against a table of mapping schemes to determine maximum isolation.

Claims

1. A method for allocating channels in a wireless access device having a plurality of radios capable of operating on a plurality of channels, the method comprising:

initially tuning each of the plurality of radios to a selected same one of the plurality of channels;

transmitting a signal at the selected same channel from a transmitting one of the plurality of radios;

receiving the signal at the selected same channel on the plurality of radios that are not the transmitting radio;

determining an error vector measurement (“

EVM”

) for each one the plurality of radios that are not the transmitting radio;

storing the EVM for each one of the plurality of radios that are not the transmitting radio for the selected same channel for the transmitting radio;

selecting a next one of the plurality of radios to transmit the signal at the same selected channel;

repeating the steps of transmitting the signal at the selected same channel, receiving the signal at the selected same channel, determining the EVM, storing the EVM, and selecting the next radio until each one of the plurality of radios has transmitted the signal at the same selected channel;

tuning each of the plurality of radios to another one of the plurality of channels;

repeating the steps of transmitting the signal at the selected same channel, receiving the signal at the selected same channel, determining the EVM, storing the EVM, selecting the next radio, and tuning the plurality of radios to the other one of the plurality of channels until each channel has been used; and

testing the EVM scores against a table of mapping schemes to determine maximum isolation.

2. A method according to claim 1 where the EVM scores for each radio at each channel is stored in memory for use in determining highest transmit rates by varying a maximum allowable transmit power in each radio.

3. A method according to claim 1 where the step of calculating the EVM comprises:

at each one of the plurality of radios that is not transmitting the signal at the selected same channel, determining characteristics of a received signal;

retrieving characteristics of a transmitted signal at the selected same channel;

comparing the characteristics of the received signal with the characteristics of the transmitted signal;

determining the EVM based on the comparison.