Active Cancellation

Hey guys,

Has anyone ever tried to make an active canceller using the USRP radios?

Basically what I would like to do is use the USRP radio to receive two
channels, one which has the noise and the other has the same noise + a
signal of interest. The goal is to use an algorithm that finds the
coefficients of an adaptive filter to cancel out the noise in the
channel
with the signal of interest and retransmit it out.

Please let me know.

Thanks!

Jan

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I am not aware of any previous work of this type, but it’s
interesting. Out of curiosity, how would you make sure the second
channel does not include the signal as well? To cancel out noise, both
receivers would need to be relatively close to each other to receive
the same noise, which means they would both receive the signal as
well.

Kunal

Well it depends, on the problem.

If you have a radio that is transmitting in the same channel as another
radio, then you can directly feed one to the noise channel and receive
the
other at the antenna.

I know in radio astronomy people have been using this technique to
cancel
interference from the earth to receive signals from the stars.

I guess it is a matter of how much isolation you can get between the
two.

Jan