GNU radio RF playback - Reg

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dinesh_gnu1
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Joined: Tue Jun 26, 2018 9:33 am

GNU radio RF playback - Reg

Post by dinesh_gnu1 » Tue Jun 26, 2018 10:29 am

Hi Team,

I am experimenting with GNU-radio companion and USRP with few exercise. But am not able to get it done precisely.

My setup is Linux Host PC(gnuradio-companion) ---- Ethernet ----> USRP ----> BTS simulator (with Antenna).

Test procedure:
1. BTS simulator is set with the RF freq - 937Mhz.
2. Recording the Time frames from the configured freq using GNUradio companion. (.grc file is attached below).
Center Freq - 937Mhz.
Channel Bandwidth - 200Khz
SAmple rate - 4Ms


Observation:
Gnu radio Freq FFT analyzer doesn't show up the spectrum from the configured center frequency. Instead complete 200Khz bandwidth is having the same signal level (around -60 dbm).

3. I tried playback of recorded RF signal (from freq 937Mhz) which is captured in the point 2. (playback .grc image is attached below).

Observation:
But we observe only noise from the playback using USRP. Noise is more when compared to data. Unable to recreate the recorded RF signals.

Do i need to change GNU Radio companion configuration? or calibrate USRP to get the spectrum for the configured Center freq as expected?

Thanks :)
Attachments
playback_window.png
playback window
playback_window.png (111.76 KiB) Viewed 5194 times
playback_grc.png
937Mhz playback grc file.
playback_grc.png (223.94 KiB) Viewed 5194 times
arfcn_5_DL_record.png
937Mhz record grc file
arfcn_5_DL_record.png (42.72 KiB) Viewed 5194 times
Last edited by dinesh_gnu1 on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
Reason: No reason

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