Amplitude jump

[kumpee]

Hello. My name is Kumpee from Thailand. I'm tring to analyze CSI data but I'm having problems with amplitude and phase jumps as shown in these images. Please check this link for the video (https://www.youtube.com/watch?v=DDH89QM4cF8)

My setup:

• Two computers (Ubuntu 16.04).
• 2 RX antennas and 2 TX antennas.
• 56 sub-carriers.
• TX send data at 500Hz approximately.
• The CSI data is send from AP to my notebook using UDP. An offline processing also face the same problem.

What causes this problem and how to avoid/solve it?

Thank you,
Kumpee