Changes between Initial Version and Version 1 of Tutorials/Wireless/FR3/OFDM

Timestamp:

Aug 19, 2025, 4:52:54 PM (3 weeks ago)

Author:

seskar

Comment:

—

Tutorials/Wireless/FR3/OFDM

@@ +1 @@
+=== OFDM Transmission Over FR3 ===
+
+This experiment transmits an analog FM signal over the FR3 bands. The FM signal is generated at 1.5 GHz by the USRP-2974 (Krypton), up-converted by a Pi-Radio FR3 front-end and transmitted,in this example, at 10 GHz). A second [https://www.pi-rad.io/ Pi-Radio] front-end down-converts this signal back to 1.5 GHz for a USRP-2974 receiver, that converts it back into analog baseband. The actual modulation and demodulations is done with a GNURadio running on 2974s. Pi-Radio web UI is used to configure the FR3 conversion. 
+
+==== Prerequisites
+
+* COSMOS account and active reservation in Sandbox 1. 
+* Familiarity with USRP-2974 (embedded X310, 10 MHz–6 GHz, 160 MHz BW).
+* FR3 hardware access (2×[https://www.pi-rad.io/ Pi-Radio] FR3 front-ends) and the fr3-tutorials.ndz disk image for the USRPs.
+* [https://www.gnuradio.org/ GNURadio] familiarity
+
+==== Resources required
+
+* Nodes: sdr1-piradio, sdr2-piradio, rfdev-sdr1-piradio, rfdev-sdr2-piradio. 
+* Antennas: 2× Vivaldi (Tx/Rx) connected to the Pi-Radio front-ends. (See FR3 hardware pages for antenna layout.) 
+* Browser access to Pi-Radio web UI on the rfdev-* nodes (port 5006).
+
+[[Include(/UserGuide/FR3Setup)]]
+
+==== Experiment Execution
+
+Use the Pi-Radio web UI Frequency panel on both rfdev pages (Tx and Rx) and set:
+
+* Low LO Frequency (GHz): 1.500000
+* High LO Frequency (GHz): 10.000000
+
+This example pairs a 1.5 GHz IF with a 10 GHz high-side LO (and a 1.5 GHz low-side LO) to place the RF tone at ~10 GHz, and back to 1.5 GHz on the receive path. (Exact placement depends on mixer sign/paths; the screenshot below shows the working settings used in this demo.) Leave Filters, Gain (except where noted), and LO Suppression at defaults for the first run.
+
+GNURadio OFDM transmitter
+
+Open a new terminal on sdr1-piradio and execute 
+{{{
+sudo -s
+cd /root/OFDM-Tutorial/
+gnuradio-companion tx_ofdm.grc
+}}}
+
+That will bring up the GNURadio companion with OFDM transmitter block diagram. Make sure to configure it to use the internal X310 (RIO device).
+
+[[Image(grc-tx.png, width=1000px)]]
+
+Run the transmitter:
+
+[[Image(grc-tx4.png, width=1000px)]]
+
+GNURadio OFDM receiver
+
+Open a new terminal on sdr2-piradio and execute 
+{{{
+sudo -s
+cd /root/OFDM-Tutorial/
+gnuradio-companion rx_ofdm.grc
+}}}
+
+That will bring up the GNURadio companion with OFDM receiver block diagram. Make sure to configure it to use the internal X310 (RIO device).
+
+[[Image(grc-rx.png, width=1000px)]]
+
+Run the receiver:
+
+[[Image(grc-rx4.png, width=1000px)]]