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dhalperi / linux-80211n-csitool-supplementary

802.11n CSI Tool based on iwlwifi and Linux-2.6
http://dhalperi.github.com/linux-80211n-csitool/
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Does 3x3 MIMO work in monitor mode? #370

Open Furyt4nk opened 6 years ago

Furyt4nk commented 6 years ago

Hi, I'm currently implementing getting AoA and ToF from CSI.

I've read many works, learned what kind of noises are there and how to mitigate it.

As far as I know, three antennas in NIC share an oscillator, which makes equal phase offset such as packet detection delay and sampling frequency offset.

I think the unwrapped phase should look similar, but the results didn't looks comprehensible.

We set the two NIC to monitor mode. One is a receiver, and the other is a transmitter.

Then we set transmitter's TX rate by command echo 0x1c113 | (skip the remaining part) and sent multiple packet.

This is the phase value we got in most cases: image

However, when we tried SIMO with monitor mode. The unwrapped phase looks similar between streams. So, we strongly guess there is some issues at doing 3x3 MIMO in monitor mode.

If you have any opinion or there are something we miss, please feel free to tell us.

Thanks.

sarahlsj commented 6 years ago

Have you figured out problem? I'm also observe the same phenomena