| | 1 | [[Include(/WikiToC)]] |
| | 2 | |
| | 3 | === Analog FM Transmission Over FR3 === |
| | 4 | |
| | 5 | 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. |
| | 6 | |
| | 7 | ==== Prerequisites |
| | 8 | |
| | 9 | * COSMOS account and active reservation in Sandbox 1. |
| | 10 | * Familiarity with USRP-2974 (embedded X310, 10 MHz–6 GHz, 160 MHz BW). |
| | 11 | * FR3 hardware access (2×[https://www.pi-rad.io/ Pi-Radio] FR3 front-ends) and the fr3-tutorials.ndz disk image for the USRPs. |
| | 12 | * [https://www.gnuradio.org/ GNURadio] familiarity |
| | 13 | |
| | 14 | ==== Resources required |
| | 15 | |
| | 16 | * Nodes: sdr1-piradio, sdr2-piradio, rfdev-sdr1-piradio, rfdev-sdr2-piradio. |
| | 17 | * Antennas: 2× Vivaldi (Tx/Rx) connected to the Pi-Radio front-ends. (See FR3 hardware pages for antenna layout.) |
| | 18 | * Browser access to Pi-Radio web UI on the rfdev-* nodes (port 5006). |
| | 19 | |
| | 20 | [[Include(/UserGuide/FR3Setup)]] |
| | 21 | |
| | 22 | ==== Experiment Execution |
| | 23 | |
| | 24 | Use the Pi-Radio web UI Frequency panel on both rfdev pages (Tx and Rx) and set: |
| | 25 | |
| | 26 | * Low LO Frequency (GHz): 1.500000 |
| | 27 | * High LO Frequency (GHz): 10.000000 |
| | 28 | |
| | 29 | 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 |
| | 30 | |
