Now for something a little different. A couple years ago I heard about the USB-DVB dongles that you could use for software radio, so I picked one up. Of course it sat around in a box until a few weeks ago, when I scratched my computer-building itch by getting an Intel NUC. The NUC DN2820 is kind of annoying due to the UEFI BIOS, but waiting around for a BIOS update paid off and I was able to install Mint 16 (Mate) using unetbootin. I installed gnuradio from the Mint repository, and librtlsdr 0.5.3 from source.
mjng@nuc ~/librtlsdr-0.5.3/src $ lsusb Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 002: ID 8087:07dc Intel Corp. Bus 001 Device 003: ID 046d:c063 Logitech, Inc. DELL Laser Mouse Bus 001 Device 005: ID 413c:2110 Dell Computer Corp. Bus 001 Device 004: ID 413c:1010 Dell Computer Corp. Bus 001 Device 007: ID 0bda:2832 Realtek Semiconductor Corp. RTL2832U DVB-T Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
mjng@nuc ~ $ rtl_test -t Found 1 device(s): 0: Generic, RTL2832U, SN: 777711111x Using device 0: Generic RTL2832U Found Elonics E4000 tuner Supported gain values (14): -1.0 1.5 4.0 6.5 9.0 11.5 14.0 16.5 19.0 21.5 24.0 29.0 34.0 42.0 Sampling at 2048000 S/s. Benchmarking E4000 PLL... [E4K] PLL not locked for 51000000 Hz! [E4K] PLL not locked for 2210000000 Hz! [E4K] PLL not locked for 1105000000 Hz! [E4K] PLL not locked for 1239000000 Hz! E4K range: 52 to 2209 MHz E4K L-band gap: 1105 to 1239 MHz
mjng@nuc ~ $ rtl_fm -f 103.7e6 -M wbfm -s 200000 -r 44100 - | aplay -r 44100 -f S16_LE Found 1 device(s): 0: Generic, RTL2832U, SN: 777711111x Using device 0: Generic RTL2832U Found Elonics E4000 tuner Tuner gain set to automatic. Tuned to 104016000 Hz. Oversampling input by: 6x. Oversampling output by: 1x. Buffer size: 6.83ms Sampling at 1200000 S/s. Output at 200000 Hz. Playing raw data 'stdin' : Signed 16 bit Little Endian, Rate 44100 Hz, Mono underrun!!! (at least 16487.192 ms long)
Playing FM radio takes 9-10% of the CPU, which although it is a Celeron, it’s a Bay Trail dual-core Celeron…
One can look for LTE signals and use them to do crystal calibration. I thought this was pretty interesting.
./CellSearch --freq-start 715e6 --freq-end 768e6 --correction 0.9999721 --ppm 10 Detected the following cells: A: #antenna ports C: CP type ; P: PHICH duration ; PR: PHICH resource type CID A fc foff RXPWR C nRB P PR CrystalCorrectionFactor 257 2 739M 1.63k -12.9 N 50 N one 0.99997430722744262699 161 2 751M 1.6k -30.7 N 50 N one 0.99997423474091573503
There seems to be an amazing amount of info out there now. I’m quite interested to dig deeper.