29 April 2009 James Sugrim Rob Miller

1. GNU Radio/USRP on the WINLAB ORBIT Nodes 29 April 2009 James Sugrim Rob Miller

2. The Story • Software Defined Radio (SDR) progress • Theory  Simulation  Experimentation The Goal Familiarity with WINLAB SDR resources. (GNU Radio / USRP)

3. The Show So Far. • Getting Started • Where the USRPs are located • Building your own image • GNU Radio/USRP Overview • Code Development • Demonstration

4. Where the radios are… In the “big” grid the following nodes have USRPs: [1,2],[1,19],[20,19],[10,11],[20,2],[5,5],[5,15],[15,5],[15,15] and USRP2s: [18,3],[3,18] In the Sandboxes, SB5 has USRPs on nodes: [1,1],[1,2] Not to scale

5. Imaging SB5(or the grid for that matter) • There are reference images that are coupled with GNU Radio software, the most recent is namedgnuradio-3.1.ndz • Utilizing the omf (or orbit) facility we can bring up nodes that have the software ready to be run. Command Syntax: > omf load NodeList ImageName Where ImageName is the Image of interest, and NodeList is specified as a bracketed, comma delimited list (e.g. [1,1],[1,2],…). Keywords like all can be substituted for a list. Example: To load the GNU Radio image onto Orbit nodes [1,2] and [20,19], use: > omf load [[1,2],[20,19]] gnuradio-3.1.ndz www.orbit-lab.org/wiki/Documentation/SupportedImages

6. Grow your own.(Not recommended) • If the stock versions are not what you’re looking for you can build your own image. • There is an apt package name gnuradio, don’t use it. • These additional sources were needed in the apt-list: • These additional package may be necessary: • It should be noted that the baseline image is based on debian (and not ubuntu) • If you check out sources from SVN there is an additional step that precedes running ./configure; ./bootstrap preconfigures configure? deb http://gnuradio.org/ubuntu stable main contrib deb-src http://gnuradio.org/ubuntu stable main deb http://ftp.at.debian.org/debian/ etch main non-free contrib • ssh2 – X11 exports • locales • Python • build-essentials • auto-make • subversion • sdcc • boost-build • wx-common • libqt3-mt-dev • libgsl0-dev • Guile • libcomedi-0.7.22

7. So Happy Together… • GNU Radio Software “blocks” that run on the GPP • Universal Software Radio Peripheral (USRP) Channelizer, DUCs/DDCs, Interpolator/Decimator • RF Daughterboards RF Interface

8. Enter the USRP • Universal Software Radio Peripheral (USRP) • ADC 64 Msps (4) • DAC 128 Msps (4) • USB 2.0 Interface* • Small FPGA† * Bottleneck: 8 MHz, 16-bit complex samples† Loads bitfile from the GPP

9. USRP2 • Uses same RF Daughterboards as USRP • Gigabit Ethernet • 100 Msps ADC (2) • 400 Msps DAC (2) • Larger FPGA • SD card reader

10. RF Daughterboards • Basic RX Receiver for use with external RF hardware • Basic TX Transmitter for use with external RF hardware • RFX2400 2.3-2.9 GHz Transceiver, 50+mW output • RFX900 800-1000MHz Transceiver, 200+mW output • RFX400 400 MHz - 500 MHz Transceiver, 100+mW output • XCVR2450 2.4-2.5 GHz and 4.9 to 5.85 GHz Dual-band Transceiver, 100+mW output on 2.4 GHz, 50+mW output on 5GHz

11. Daughterboard Deployment Node USRP USRP CoordinateSide ASide B (1,2) FLEX-400 FLEX-2400 (1,19) FLEX-400 FLEX-2400 (20,19) FLEX-400 FLEX-2400 (10,11) FLEX-400 FLEX-2400 (20,2) FLEX-400 RFX-2400 (15,5) FLEX-900 RFX-2400 (15,15) XCVR-2450 RFX-2400 (5,15) FLEX-900 FLEX-2400 (5,5) XCVR-2450 RFX-2400 (18,3)* XCVR-2450 - (3,18)* XCVR-2450 - SB5(1,1) Basic TX/RX - SB5(1,2) Basic TX/RX - *USRP2

12. Signal processing ‘blocks’ • Implemented in C++ but callable from python • Program development • ‘Glue’ together existing blocks in python https://radioware.nd.edu/documentation/a-dictionary-of-the-gnu-radio-blocks • Build your own https://radioware.nd.edu/documentation/advanced-gnuradio

13. Simple Python Example src0 dst src1 Reference: www.joshknows.com

14. Simple USRP Example #1 #!/usr/bin/env python from gnuradio import gr from gnuradio import usrp from optparse import OptionParser from usrpm import usrp_dbid u_source = usrp.source_c() u_sink = usrp.sink_c() subdev_Ar = usrp.selected_subdev(u_source, (0,0)) subdev_Br = usrp.selected_subdev(u_source, (1,0)) subdev_At = usrp.selected_subdev(u_sink, (0,0)) subdev_Bt = usrp.selected_subdev(u_sink, (1,0)) print"RX d'board %s" % (subdev_Ar.side_and_name(),) print"RX d'board %s" % (subdev_Br.side_and_name(),) print"TX d'board %s" % (subdev_At.side_and_name(),) print"TX d'board %s" % (subdev_Bt.side_and_name(),) import necessary modules setup usrp as source and sink specify subdevices print out names File location: gr‑utils\src\python\usrp_print_db.py

15. Simple USRP Example #2 usrp complex head complex file sink self.u = usrp.source_c(decim_rate=options.decim) self.dst = gr.file_sink(gr.sizeof_gr_complex, filename) self.head = gr.head(gr.sizeof_gr_complex, int(options.nsamples)) self.connect(self.u, self.head, self.dst) options.rx_subdev_spec = usrp.pick_rx_subdevice(self.u) self.u.set_mux(usrp.determine_rx_mux_value(self.u, options.rx_subdev_spec)) self.subdev = usrp.selected_subdev(self.u, options.rx_subdev_spec) input_rate = self.u.adc_freq() / self.u.decim_rate() self.subdev.set_gain(options.gain) r = self.u.tune(0, self.subdev, options.freq) key excerpts from usrp_rx_cfile.py File location: gr‑utils\src\python\usrp_rx_cfile.py

16. Simple USRP Example #2 Goal: Collect 1 second of data at 2.41 GHz with a sample rate of 500 KHz. Use Node (1,19) in the ORBIT grid and store the data in myfile.dat • Decimation: 64 MHz/500 KHz = 128 • 500 KHz x 1 second = 500e3 samples usrp complex head complex file sink Node USRP Side A USRP Side B (1,19) FLEX-400 FLEX-2400 >> ./usrp_rx_cfile.py –R B –f 2410M –d 128 –N 500e3 myfile.dat File location: gr‑utils\src\python\usrp_rx_cfile.py

17. Building the house block by block • How-to-build-a-block • Develop C++ signal processing • Make callable from python (SWIG) • Test the block • Install and use the block from gnuradio import myblock Good starting points radioware.nd.edu/documentation/advanced-gnuradio www.gnu.org/software/gnuradio/doc/howto-write-a-block.html

18. Demo – Sandbox 5 • (1) benchmark_tx.py to usrp_fft.py • (2) benchmark_tx.py to benchmark_rx.py File locations: gr‑utils\src\python\usrp_fft.py gnuradio-examples\python\digital\benchmark_tx.py gnuradio-examples\python\digital\benchmark_rx.py

19. USRP Debug Tidbit • uUuUuU USRP Underruns: Not enough samples are ready to send to USRP sink. • uOuOuO USRP Overruns: USRP samples have been dropped because they weren't read in time.

20. Suggestions • Log into the sandbox and play!

21. Relevant References • www.ettus.com • www.gnu.org/software/gnuradio/ • www.gnuradio.org • www.joshknows.com • radioware.nd.edu/documentation • Dawei Shen tutorials moved here • Dictionary of GNU Radio blocks • www.orbit-lab.org • www.gnu.org/software/gnuradio/doc/howto-write-a-block.html

22. Questions?

23. Extra Slides Follow

24. usrp.source_c ( int which_board, unsigned int decim_rate,  int nchan = 1, int mux = -1, int mode = 0 )

25. USRP boot sequence When the USRP is powered up, it puts the AD9862 is a low power state, and blinks the led 3 times per second. The host (computer) detects a USB device 04b4:8613, and therefore knows it is an unconfigured FX2 device. The driver will now load a firmware into the FX2, and when it boots up, the host will now detect a different USB device of fffe:0002. Using a capability of the newly loaded FX2 firmware, the driver will now initialize the FPGA. Once that is done, boot is complete, and the device is ready for tuning Reference: en.wikipedia.org/wiki/Universal_Software_Radio_Peripheral

26. Abstract • Recent advancements in the area of Software Defined Radio (SDR) haveopened the door for researchers to complement theoretical findings andsimulations with real world experimentation. A very popular SDR, used inboth academia and industry, is the Universal Software Radio Peripheral(USRP). Much experimentation has been done using this SDR in conjunction with GNU Radio signal processing blocks. The primary focus of this talk is to get new users involved with the GNU Radio/USRP resources available at WINLAB. In this talk, we will discuss how to access and develop on these platforms. We will also provide a high level description of theUSRP architecture, and an overview of the steps involved in implementingsignal processing routines. Additionally, we will comment on lessonslearned regarding the installation of GNU Radio onto the WINLAB nodes.Links and references to more detailed documentation will also beprovided.