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Full Duplex

Timestamp:: Sep 17, 2020, 5:18:08 PM (4 years ago)
Author:: mpk2138
Comment:: —

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Tutorials/Wireless/Full Duplex

-              v28
+              v29
 * Manav Kohli, Columbia University: mpk2138[at]columbia.edu
 Last updated: August 28, 2020
+Last updated: September 17, 2020
 == Full-Duplex Wireless in COSMOS ==
 === Description ===
 In this tutorial, we will use the two integrated Gen-2 FD radios equipped with USRP N210 software defined radios (SDRs) and the Gen-2 frequency-domain equalization (FDE) based RF canceller box. The testbed may be accessed via {{{ssh}}}. The PC contains several example experiments, which showcase the capabilities of the FD transceivers.
+In this tutorial, we will use the two integrated Columbia [http://flexicon.ee.columbia.edu/ FlexICoN] Gen-2 Wideband FD radios equipped with USRP N210 software defined radios (SDRs) and the Gen-2 frequency-domain equalization (FDE)-based RF canceller box. The testbed may be accessed via {{{ssh}}}. The PC contains several example experiments, which showcase the capabilities of the FD transceivers.
  ||||||Figure 1: Gen-2 FDE Canceller Boxes in COSMOS Sandbox 2 ||
 …
 For more information about the integration of the FDE-based FD transceivers in COSMOS, please read:
 . ''Manav Kohli, Tingjun Chen, Mahmood Baraani Dastjerdi, Jackson Welles, Ivan Seskar, Harish Krishnaswamy, and Gil Zussman, “Open-access full-duplex wireless in the ORBIT and COSMOS testbeds,” in Proc. ACM !MobiCom’20 Workshop on Wireless Network Testbeds, Experimental evaluation & CHaracterization (WiNTECH) (to appear) (invited), Sept. 2020'' [https://wimnet.ee.columbia.edu/wp-content/uploads/2020/08/wintech2020_orbit_cosmos_fullduplex_integration.pdf (Download)]
+. ''Manav Kohli, Tingjun Chen, Mahmood Baraani Dastjerdi, Jackson Welles, Ivan Seskar, Harish Krishnaswamy, and Gil Zussman, “Open-access full-duplex wireless in the ORBIT and COSMOS testbeds,” in Proc. ACM !MobiCom’20 Workshop on Wireless Network Testbeds, Experimental evaluation & CHaracterization (WiNTECH) (invited), Sept. 2020'' [https://wimnet.ee.columbia.edu/wp-content/uploads/2020/08/wintech2020_orbit_cosmos_fullduplex_integration.pdf (Download)] [https://wimnet.ee.columbia.edu/wp-content/uploads/2020/08/mobicom2020_cosmos_fullduplex_demo.pdf (Demo Abstract)]
 . ''Tingjun Chen, Mahmood Baraani Dastjerdi, Jin Zhou, Harish Krishnaswamy, and Gil Zussman, “Wideband Full-Duplex Wireless via Frequency-Domain Equalization: Design and Experimentation,” in Proc. ACM !MobiCom'19, Oct. 2019'' [https://wimnet.ee.columbia.edu/wp-content/uploads/2018/12/FDE_MobiCom19.pdf (Download)]
 …
 '''Details on configuring the canceller PCB'''
 Using the experiment {{{node_level_sic_fd_gui}}}, the experimenter can configure the RF canceller PCB using the experiment GUI. There are 12 sliders:
+Using the experiment {{{node_level_sic_fd_gui}}}, the experimenter can configure the RF canceller PCB using the experiment GUI. There are 14 sliders:
  * {{{cap0, cap1, cap2}}} - these control the antenna tuner.
  * {{{att0, att1}}} - The attenuator values for FDE tap 0 and tap 1. Higher values lead to greater attenuation.
 …
 == Full-Duplex Wireless in ORBIT ==
 === Description ===
 In this tutorial, we'll use node11-10 in the main grid (equipped with a USRP N210) to transmit and receive a single tone over the air to demonstrate full-duplex wireless capability using the Columbia [http://flexicon.ee.columbia.edu/ FlexICoN]'s Gen-1 Frequency-Flat Amplitude- and Phase-based RF Canceller. Pictures of the FlexICoN RF canceller and node11-10 in the main grid equipped with full-duplex capability are below:
+In this tutorial, we'll use node11-10 in the main grid (equipped with a USRP N210) to transmit and receive a single tone over the air to demonstrate full-duplex wireless capability using the Columbia [http://flexicon.ee.columbia.edu/ FlexICoN]'s Gen-1 Narrowband Frequency-Flat Amplitude- and Phase-based RF Canceller. Pictures of the FlexICoN RF canceller and node11-10 in the main grid equipped with full-duplex capability are below:
  ||||||Figure 1: The ORBIT-FlexICoN Full-Duplex Node||
  || [[Image(FlexICoN-gen1-canceller.jpg, 325px)]] [[Image(FlexICoN-gen1-canceller-label.png, 350px)]] || [[Image(FlexICoN-gen1-node11-10.jpg, 400px)]] ||
  || (a) The FlexICoN RF Canceller Box  || (b) Full-Duplex SDR at node11-10 in the ORBIT grid  ||
 ==== Technical Report ====
+==== Publications ====
 For more information, please read:
 ''Tingjun Chen, Mahmood Baraani Dastjerdi, Guy Farkash, Jin Zhou, Harish Krishnaswamy, and Gil Zussman, “Open-access full-duplex wireless in the ORBIT testbed,” arXiv preprint: 1801.03069v2 [cs.NI], May 2018.'' [https://arxiv.org/abs/1801.03069 (arXiv report)] [http://wimnet.ee.columbia.edu/wp-content/uploads/2018/03/INFOCOM18Demo_FullDuplexORBIT.pdf (INFOCOM'18 Demo Abstract)]
 Please cite the above arXiv report if you use the hardware. Please email Tingjun Chen (tingjun [at] ee.columbia.edu) if you use (or plan to use) the full-duplex node or if you have any questions.
+''Manav Kohli, Tingjun Chen, Mahmood Baraani Dastjerdi, Jackson Welles, Ivan Seskar, Harish Krishnaswamy, and Gil Zussman, “Open-access full-duplex wireless in the ORBIT and COSMOS testbeds,” in Proc. ACM !MobiCom’20 Workshop on Wireless Network Testbeds, Experimental evaluation & CHaracterization (WiNTECH) (invited), Sept. 2020'' [https://wimnet.ee.columbia.edu/wp-content/uploads/2020/08/wintech2020_orbit_cosmos_fullduplex_integration.pdf (Download)] [https://wimnet.ee.columbia.edu/wp-content/uploads/2020/08/mobicom2020_cosmos_fullduplex_demo.pdf (Demo Abstract)]
+Please cite the above arXiv report if you use the hardware. Please email Tingjun Chen (tingjun [at] ee.columbia.edu) or Manav Kohli (mpk2138 [at] columbia.edu) if you use (or plan to use) the full-duplex node or if you have any questions.
 ==== Updates ====
+* [09/17/2020]: New full-duplex SDR image {{{flexicon-orbit-v4.ndz}}} released. The real-time OFDM-based full-duplex flowgraph and GNU OOT modules have been updated. Obsolete experiments have been removed.
 * [04/30/2019]: New full-duplex SDR image {{{flexicon-orbit-v3.ndz}}} released. Main new feature includes the implementation of a real-time OFDM-based full-duplex node.
 * [01/31/2019]: Developed real-time digital SIC as a GNU Radio OOT module.
 …
 === Hardware / Software Resources Utilized ===
 . The Columbia FlexICoN Gen-1 RF Canceller, which is a frequency-flat amplitude- and phase-based RF canceller implemented using discrete components on a PCB. The Gen-1 RF canceller is optimized to have a center operating frequency at 900MHz.
 . The source code for the full-duplex transceiver examples, which can be found at [https://github.com/Wimnet/flexicon_orbit this GitHub page]. We have also built an ORBIT node image {{{flexicon-orbit-v2.ndz}}} with all the required software installed to facilitate the experiments.
+. The Columbia FlexICoN Gen-1 RF Canceller, which is a frequency-flat ''narrowband'' amplitude- and phase-based RF canceller implemented using discrete components on a PCB. The Gen-1 RF canceller is optimized to have a center operating frequency at 900MHz.
+. The source code for the full-duplex transceiver examples, which can be found at [https://github.com/Wimnet/flexicon_orbit this GitHub page]. We have also built an ORBIT node image {{{flexicon-orbit-v4.ndz}}} with all the required software installed to facilitate the experiments.
 . USRP N210 with {{{node11-10}}} in the ORBIT main grid.
 . [http://www.xdimax.com/sub20/sub20.html SUB-20] is a multi-interface USB adapter for providing popular interfaces between PC (USB host) and different hardware devices. Specifically, we use the SUB-20 SPI module to control and configure the Gen-1 RF canceller (see Fig. 1(a)). The user manual can be found [http://www.xdimax.com/sub20/doc/sub20-man.pdf here]. We also built a GNU Radio Out-Of-Tree (OOT) module to allow controlling the canceller from within the GNU Radio GUI.
 …
 . The {{{Eigen C++}}} Library is used for basic algebra used in channel estimation and digital self-interference cancellation. The Eigen releases can be found on the [http://eigen.tuxfamily.org/index.php?title=Main_Page this website]. We used the latest stable release Eigen 3.3.4 through our testings and experiments.
+=== Set Up ===
+=== Tutorial ===
+==== Set Up ====
 Before you can access the testbed, you need to [https://www.orbit-lab.org/schedule make a reservation] and get it approved. After receiving the reservation's confirmation (approval) email:
  * Login into reserved domain: {{{ssh -X username@conslole.grid.orbit-lab.org}}} (the {{{-X}}} option is for enabling the X11 tunneing)
  * Make sure that the full-duplex node is powered down for loading the desired image: {{{omf tell -a offh -t node11-10}}}
  * Load the most updated full-duplex node image (currently full-duplex SDR image {{{flexicon-orbit-v3.ndz}}} released) on the node (this process can take about a few minutes so please be patient): {{{omf load -i flexicon-orbit-v3.ndz -t node11-10}}}
+ * Load the most updated full-duplex node image (currently {{{flexicon-orbit-v4.ndz}}}) on the node (this process can take about a few minutes so please be patient): {{{omf load -i flexicon-orbit-v4.ndz -t node11-10}}}
  * Turn on the node: {{{omf tell -a on -t node11-10}}}
  * Login into the node: {{{ssh -X root@node11-10}}}. After login into the node, a {{{flexicon_orbit}}} folder should exist under the home directory of {{{node11-10:~/}}} which contains the source code of this example. You can also retrieve the most recently updated code from [https://github.com/Wimnet/flexicon_orbit the GitHub repository].
 …
  * Run {{{sudo sysctl -w net.core.rmem_max=50000000}}} and {{{sudo sysctl -w net.core.wmem_max=50000000}}}
  * Check the conection and serial number of the USRP N210: {{{uhd_find_devices}}}. The serial number should be {{{F331D4}}}.
+=== Run the Experiments ===
+You will need to login into the full-duplex node (by {{{ssh root@node11-10}}}) in two separate terminal windows lo for running the experiment: one for the main full-duplex transceiver UHD program and one for controlling the RF canceller.
+=== Example Experiment 1: A Real-Time Full-Duplex Radio with OFDM PHY (GNU Radio + UHD) ===
+* Within the FD node (i.e., {{{ssh -X root@node11-10}}}, open the GNU Radio flowgraph {{{~/flexicon_orbit/fd_transceiver_ofdm/grc/ofdm_node_fd.grc}}} in {{{gnuradio-companion}}}, as shown below.
+ || [[Image(flexicon_orbit_grc_ofdm_node.png, 1000px)]] ||
+ || GNU Radio flowgraph of the OFDM-based FD radio example experiment. ||
+* Run the experiments, three plots will show up: Time-domain Rx signal after RF SIC and digital SIC (@tab0), frequency-domain Rx signal after RF SIC and digital SIC (@tab1), and the estimated coefficients of the digital SI canceller taps (@tab2).
+ || [[Image(flexicon_orbit_grc_ofdm_node_tab0.png, 333px)]]  || [[Image(flexicon_orbit_grc_ofdm_node_tab1.png, 333px)]]  || [[Image(flexicon_orbit_grc_ofdm_node_tab2.png, 333px)]] ||
+ ||||||Time-domain and frequency-domain Rx signal after RF and digital SIC, and estimated digital SI canceller coefficients on the packet-level. ||
+=== Example Experiment 2: A Simple Full-Duplex Radio Experiment (Terminal + UHD) ===
+==== In Terminal 1 ====
+ * Set an initial configuration for the Gen-1 canceller PCB:
+{{{#!shell-session
+root@node11-10:~ cd flexicon_orbit/fd_transceiver_simple/sub20
+root@node11-10:~/flexicon_orbit/fd_transceiver_simple/sub20# ./rf_canc_gen1_config 0 127 16 6 6
+Started...
+Sub20 device found... Serial Number is 48AB
+Device Opened!
+...Finished programming DAC with value 0!
+...Finished programming ATT with value 127!
+...Finished programming CAP1 with value 16!
+...Finished programming CAP2 with value 6!
+...Finished programming CAP3 with value 6!
+}}}
+==== Running experiments ====
+We provide two sets of experiments. One set is for GNU Radio, which are identical to the experiments described above in COSMOS and located at {{{~/flexicon_orbit/experiments/grc/}}}. To run these experiments, open them from GNU radio after running the {{{gnuradio-companion}}} command. Please note that due to there only being one FD radio present in ORBIT, the two link experiments in GNU Radio are not supported. The flowgraphs are kept present for reference.
+The other set which are based on UHD, and are legacy experiments - they implement simpler full-duplex transceivers with no available GUI and are also kept for reference.
+'''Details on configuring the canceller PCB'''
+Using the experiment {{{node_level_sic_fd_gui}}}, the experimenter can configure the RF canceller PCB using the experiment GUI. There are 2 sliders:
+* {{{att_0}}} - The attenuator value for the canceller. Higher values lead to greater attenuation.
+* {{{dac0}}} - The phase shifter values for the canceller.
+=== Available Experiments ===
+==== node_level_sic_fd_gui (GNU Radio) ====
+The primary use of this experiment is to visualize the performance of the FD radio. As the Gen-1 canceller operates in a narrow band, the cancellation bandwidth will be noticeably less than the Gen-2 FD radios available in COSMOS.
+In this experiment, several performance metrics are visualized:
+ * The received self-interference (SI) after RF SI cancellation (SIC) and after digital SIC.
+ * The received power spectra after RF SIC and after digital SIC.
+ * The complex-valued digital SIC filter taps.
+ * The estimated SI channel.
+'''Tunable variables'''
+ * {{{freq}}} - the carrier frequency used. The Gen-1 hardware can support roughly 900-1000MHz.
+ * {{{samp_rate}}} - the bandwidth used. As the canceller is narrowband, we recommend using no more than a 5 MHz bandwidth.
+==== fd_transciever_simple (Terminal + UHD) ====
+This experiment can be used to show the amount of achieved SIC in the RF and digital domains using a command-line interface. It is included here as reference and an example of a full-duplex transceiver implemented in UHD.
+We recommend using two terminals here, so one terminal can be used to run the experiment in the foreground while the second is used to control the FD radio.
+'''In Terminal 1'''
  * Prepare the Eigen library (you can skip this step since the image already contains the Eigen library):
 {{{#!shell
 …
  In this example, since the TX power level is at 0dBm, a total amount of around 90dB self-interference cancellation is achieved, of which 45dB is obtained by the Gen-1 RF canceller, and 50dB is obtained by the digital cancellation.
+===== In Terminal 2 (SUB-20) =====
+'''In Terminal 2 (SUB-20)'''
  * Build the RF canceller configuration code (this is already done in the loaded image):
 {{{#!shell
 …
 }}}
  In particular, the {{{PS-CODE=0,1,2,...,255}}} and {{{ATT-CODE=0,1,2,...,127}}} codes are for configuring the 8-bit phase shifter and the 7-bit attenuator of the Gen-1 RF canceller, respectively. It is recommended to use {{{C1-CODE=16, C2-CODE=6, C3-CODE=6}}}, which provides 20dB isolation from the antenna-circulator interface. You can play with the values of {{{ATT}}} and {{{PS}}} until you see good cancellation profile (e.g., low residual self-interference power level) in Terminal 1.
  * An example temrinal output is below:
+ * An example terminal output is below:
 {{{#!shell-session
 root@node11-10:~/flexicon_orbit/fd_transceiver_simple/sub20# ./rf_canc_gen1_config 110 30 16 6 6
 …
 }}}
+==== A Secondary Transmitter Using Node13-8 ====
+'''A Secondary Transmitter Using Node13-8'''
 Once the full-duplex node11-10 is up and running, you can turn on another SDR to transmit to the full-duplex node. Below, we use {{{node13-8}}} as an example in the 3rd terminal window (Terminal 3).
  * Load image, power on, and login into node13-8:
 …
  Now by analyzing the RX baseband data at node11-10, you will observe the received tone at 200kHz while the self-interence tone at 100kHz is cancelled to the USRP noise floor, which is around -90dBm.
+==== Acknowledgements ====
+The secondary transmitter can also be used while running the GNU radio flowgraph {{{node_level_sic_fd_gui}}} which will visualize the received signal from {{{node13-8}}}.
+=== Acknowledgements ===
 This work was supported in part by NSF grant ECCS-1547406, DARPA RF-FPGA program, DARPA SPAR program, a Qualcomm Innovation Fellowship, a National Instruments Academic Research Grant, Texas Instruments, and Intel. We thank Steven Alfano, Jelena Diakonikolas, Aishwarya Rajen, Jinhui Song, Mingyan Yu for their contributions to various aspects of the project. We thank Ivan Seskar, Jakub Kolodziejski, and Prasanthi Maddala from WINLAB, Rutgers University, for their help on the integration with the ORBIT testbed. We also thank Kira Theuer and Kendall Ruiz from NI and the NI technical support team for their help.