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Hello,
I am planning to use WARP to capture wifi signals in the air from a non-WARP device, e.g., smartphone, laptop. After successfully capturing the signal, I would like to get the channel estimation. I am talking about the OFDM modulation.
As there are WARP 802.11 reference design and WARPLab. I would like to enquire the following things.
(1) WARP 802.11 reference design
Is this example logging all the wifi transmissions in the air?
log_capture_continuous
(2) WARPLab
Can I use the WARPLab to log all the wifi transmission in the air? Is this Spectrogram the right example?
Best regards,
Junqing
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Junqing Zhang wrote:
(1) WARP 802.11 reference design
Is this example logging all the wifi transmissions in the air?
log_capture_continuous
That will log all Wi-Fi transmissions in the air for the specified WLAN channel and provided that the Wi-Fi packets are sufficiently high SNR that they can at least get through packet detection and SIGNAL decoding in the PHY. Those log entries do include the PHY's channel estimates in them.
Junqing Zhang wrote:
(2) WARPLab
Can I use the WARPLab to log all the wifi transmission in the air? Is this Spectrogram the right example?
WARPLab will capture the raw waveforms, but it's up to your MATLAB to process those waveforms into the data you need. To get subcarrier channel estimates, you'd need to implement a decent chunk of an 802.11 receiver in MATLAB. That spectrogram example isn't doing that.
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chunter wrote:
WARPLab will capture the raw waveforms, but it's up to your MATLAB to process those waveforms into the data you need. To get subcarrier channel estimates, you'd need to implement a decent chunk of an 802.11 receiver in MATLAB. That spectrogram example isn't doing that.
Hello Chris, does this require the decoding of both the MAC layer and PHY layer?
Last edited by Junqing Zhang (2018-Aug-09 10:48:15)
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At a minimum you would need to detect the existence of a preamble and then calculate channel estimates from the extracted LTF. If you want to know who sent the packet, you'd need to be able to decode the MAC payload and extract the transmit address. That's a larger undertaking.
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