wiki:Tutorials/Wireless/mmwavePaamBasics

IBM 28GHz PAAM Basics

Description

In this tutorial, we demonstrate the basic use of the IBM 28 GHz phased array antenna modules (PAAMs) with USRP N310 software-defined radios (SDRs) in the COSMOS Sandbox2 (sb2).

The following paper describes the integration of the IBM 28 GHz PAAMs (beta-version) with USRP SDRs in the COSMOS testbed. We would appreciate it if you cite this paper when publishing results obtained using the PAAMs deployed in COSMOS.

  • X. Gu, A. Paidimarri, B. Sadhu, C. Baks, S. Lukashov, M. Yeck, Y. Kwark, T. Chen, G. Zussman, I. Seskar, and A. Valdes-Garcia, "Development of a compact 28-GHz software-defined phased array for a city-scale wireless research testbed," in Proc. IEEE International Microwave Symposium (IMS’21) (to appear), 2021.

Author: Tingjun Chen, Duke University / Columbia University (tingjun.chen [at] duke [dot] edu)

Last updated: Apr. 11, 2021

Acknowledgements

This work is collaboration with IBM. We thank Xiaoxiong Gu, Arun Paidimarri, Bodhisatwa Sadhu, and Alberto Valdes-Garcia for their contributions and support. More detailed information about the IBM 28 GHz PAAM can be found in the following references:

  • B. Sadhu, Y. Tousi, J. Hallin, S. Sahl, S. K. Reynolds, O. Renstrom, K. Sjogren, O. Haapalahti, N. Mazor, B. Bokinge, G. Weibull, H. Bengtsson, A. Carlinger, E. Westesson, J. Thillberg, L. Rexberg, M. Yeck, X. Gu, M. Ferriss, D. Liu, D. Friedman, A. Valdes-Garcia, "A 28-GHz 32-element TRX phased-array IC with concurrent dual-polarized operation and orthogonal phase and gain control for 5G communications," IEEE Journal of Solid-State Circuits, vol. 52, no. 12, pp. 3373-3391, 2017.

Prerequisites

In order to access sb2, create a reservation in sb2 and have it approved by the reservation service. Access to the resources is granted after the reservation is confirmed. Please follow the process shown on the COSMOS getting started page to get started.

Resources Required

In this tutorial we will use the following hardware resources in sb2, which are also shown in the figure below.

  • 2 USRP N310 SDRs (sdr1-s1-lg1 and sdr1-md1)
  • 2 IBM 28GHz PAAMs (rfdev2-1 and rfdev2-2)
  • 1 Server (srv1-lg1)

The current hardware connection in sb2:

  • sdr1-s1-lg1 RF2 TX/RX — rfdev2-1 IC1/TX/H, sdr1-s1-lg1 RF2 RX2 — rfdev2-1 IC2/RX/H
  • sdr1-md1 RF2 TX/RX — rfdev2-2 IC1/TX/H, sdr1-md1 RF2 RX2 — rfdev2-2 IC2/RX/H

Tutorial Setup

Follow the steps below to gain access to the sb2 console and set up nodes with appropriate images.

  1. If you don't have one already, sign up for a COSMOS account
  2. Create a resource reservation on COSMOS sb2
  3. Login into sb2 console (console.sb2.cosmos-lab.org) with two SSH sessions.
  4. Make sure all the nodes and devices used in the experiment are turned off:
    omf tell -a offh -t sdr1-s1-lg1,sdr1-md1,rfdev2-1,rfdev2-2,srv1-lg1
    
  5. Use the baseline-28ghz-paam.ndz node image with Ubuntu 18.04, UHD 3.15, gnuradio 3.8, and the IBM 28GHz PAAM API. Load baseline-28ghz-paam.ndz on the server.
    omf load -i baseline-28ghz-paam.ndz -t srv1-lg1
    
  6. Turn all the required resources on and check the status of all resources
    omf tell -a on -t sdr1-s1-lg1,sdr1-md1,rfdev2-1,rfdev2-2,srv1-lg1
    
    omf stat -t system:topo:allres
    
  7. ssh to the the same server from two terminals. In the first terminal, use option -Y for using GUI with gnuradio. In the second terminal, option -Y is not needed as it will be used to control the two IBM 28GHz PAAMs via command lines.
    [Terminal 1] ssh -Y root@srv1-lg1,
    [Terminal 2] ssh root@srv1-lg1,
    

Experiment Execution

Find and prepare USRPs and the IBM 28GHz PAAM API

  • The IP addresses for SFP+0 (10G) on sdr1-s1-lg1 and sdr1-md1 were hard-coded to 10.117.2.1 and 10.117.3.1, respectively. To access them from srv1-lg1, configure the network interface eno1 as follows:
    root@srv1-lg1:~# ifconfig eno1 10.117.1.1 netmask 255.255.0.0 mtu 9000 up
    root@srv1-lg1:~# sudo sysctl -w net.core.wmem_max=62500000
    net.core.wmem_max = 62500000
    root@srv1-lg1:~# sudo sysctl -w net.core.rmem_max=62500000
    net.core.rmem_max = 62500000
    root@srv1-lg1:~# ifconfig 
    eno1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 9000
            inet 10.117.1.1  netmask 255.255.0.0  broadcast 10.117.255.255
            inet6 fe80::1e34:daff:fe42:d4c  prefixlen 64  scopeid 0x20<link>
            ether 1c:34:da:42:0d:4c  txqueuelen 1000  (Ethernet)
            RX packets 15305870  bytes 21326136765 (21.3 GB)
            RX errors 0  dropped 46450  overruns 0  frame 0
            TX packets 16288829  bytes 21257264625 (21.2 GB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    
  • Run und_find_device to make sure that both USRP N310s can be reached:
    root@srv1-lg1:~# uhd_find_devices 
    [INFO] [UHD] linux; GNU C++ version 7.5.0; Boost_106501; UHD_3.15.0.HEAD-0-gaea0e2de
    --------------------------------------------------
    -- UHD Device 0
    --------------------------------------------------
    Device Address:
        serial: 315A35A
        addr: 10.117.2.1
        claimed: True
        mgmt_addr: 10.116.2.1
        mgmt_addr: 10.117.2.1
        mgmt_addr: 10.118.2.1
        product: n310
        type: n3xx
    
    --------------------------------------------------
    -- UHD Device 2
    --------------------------------------------------
    Device Address:
        serial: 3176DF7
        addr: 10.117.3.1
        claimed: True
        mgmt_addr: 10.116.3.1
        mgmt_addr: 10.117.3.1
        mgmt_addr: 10.118.3.1
        product: n310
        type: n3xx
    

Execution

Run the experiment

  • [Terminal 1] In the first terminal, start gnuradio companion and open the example experiment that established a single tone transmission:
    root@srv1-lg1:~# gnuradio-companion example_paam_tone.grc 
    
  • [Terminal 1] In gnuradio-companion, start gnuradio-companion, configure the USRP sink (TX) with sdr1-s1-lg1 ("mgmt_addr=10.116.2.1,addr=10.117.2.1") and the USRP source (RX) with sdr1-md1 ("mgmt_addr=10.116.3.1,addr=10.117.3.1"). Set the carrier frequency to 3GHz (3e9) and the subdev to be "B:0" (RF2) on both TX and RX. In this example flowgraph, the sampling rate and the tone frequency are set to be 2.5MHz (2.5e6) and 1MHz (1e6), respectively.
mmWave PAAM basics grc flowgraph
  • [Terminal 2] In the second terminal, change directory to paam_api/examples/ which contains the example API scripts.
    root@srv1-lg1:~# cd paam_api/examples/
    
  • [Terminal 2] First, start PAAM #1 (rfdev2-1) in TX mode with H-polarization using 4 antenna elements on IC 1, and configure the TX beamforming direction to be in the broadside (0,0). Check the current consumption on 2v7_1 and make sure IC1 has been successfully initialized (e.g., 2v7_1 has a current consumption of 1.026A in the example below).
    root@srv1-lg1:~/paam_api/examples# python3 setup_betaboard_v1.2.py -c ethernet -a rfdev2-1 --ic 1 -n 4 --txrx tx --pol h --dir 0 0
    TRX mode selection: tx
    IC(s) used for experiment: [1]
    Number of Elements per IC: 4
    Polarization: h
    Beam direction: (0, 0)
    IP address of TX: rfdev2-1
    Opened port to FPGA
    Logged in to Petalinux
    Started command parser on Zynq
    sdpar_prog.py /version: Version is PAWR_v1.2.0
    Using baseline FPGA control IP
    Reset the Phased Array
    Initialization of IC 0 was successful
    Initialization of IC 1 was successful
    Initialization of IC 2 was successful
    Initialization of IC 3 was successful
    elapsed time for init: 5.458436489105225
    Time for PAWR Board utilities configuration: 0.07273483276367188
    elapsed time for enable: 0.00990605354309082
    elapsed time for steer beam: 0.0026137828826904297
    PAAM ID: 0x 2
    LO switch: PLL
    IF Switches TX_H: 0xF
    IF Switches TX_V: 0xF
    IF Switches RX_H: 0xF
    IF Switches RX_V: 0xF
    Index   Name    ADC Volt.   Curr.
    0   1v2 21  0.051   0.026
    1   1v5 154 0.376   0.753
    2   1v8 3   0.007   0.004
    3   2v7_0   16  0.039   0.078
    4   2v7_1   210 0.513   1.026
    5   2v7_2   44  0.108   0.215
    6   2v7_3   44  0.108   0.215
    7   3v3_pll 367 0.897   0.448
    8   5v_uzed 249 0.609   0.609
    9   12v 124 0.303   1.010
    10  0V  0   0.000   x
    11  1V8 735 1.796   x
    Closed port to Zynq
    Good luck with the experiment!!!
    
  • [Terminal 2] Similarly, start PAAM #2 (rfdev2-2) in RX mode with H-polarization using 4 antenna elements on IC 2, and configure the RX beamforming direction to be in the broadside (0,0). Check the current consumption on 2v7_2 and make sure IC2 has been successfully initialized (e.g., 2v7_2 has a current consumption of 0.821A in the example below).
    root@srv1-lg1:~/paam_api/examples# python3 setup_betaboard_v1.2.py -c ethernet -a rfdev2-2 --ic 2 -n 4 --txrx rx --pol h --dir 0 0
    TRX mode selection: rx
    IC(s) used for experiment: [2]
    Number of Elements per IC: 4
    Polarization: h
    Beam direction: (0, 0)
    IP address of TX: rfdev2-2
    Opened port to FPGA
    Logged in to Petalinux
    Started command parser on Zynq
    sdpar_prog.py /version: Version is PAWR_v1.2.0
    Using baseline FPGA control IP
    Reset the Phased Array
    Initialization of IC 0 was successful
    Initialization of IC 1 was successful
    Initialization of IC 2 was successful
    Initialization of IC 3 was successful
    elapsed time for init: 5.453927516937256
    Time for PAWR Board utilities configuration: 0.07044315338134766
    elapsed time for enable: 0.008872270584106445
    elapsed time for steer beam: 0.002682209014892578
    PAAM ID: 0x 4
    LO switch: PLL
    IF Switches TX_H: 0xF
    IF Switches TX_V: 0xF
    IF Switches RX_H: 0xF
    IF Switches RX_V: 0xF
    Index   Name    ADC Volt.   Curr.
    0   1v2 127 0.310   0.155
    1   1v5 134 0.327   0.655
    2   1v8 18  0.044   0.022
    3   2v7_0   42  0.103   0.205
    4   2v7_1   51  0.125   0.249
    5   2v7_2   168 0.411   0.821
    6   2v7_3   13  0.032   0.064
    7   3v3_pll 34  0.083   0.042
    8   5v_uzed 249 0.609   0.609
    9   12v 129 0.315   1.051
    10  0V  0   0.000   x
    11  1V8 735 1.796   x
    Closed port to Zynq
    Good luck with the experiment!!!
    

Observe the results

The left figure shows the frequency response of the received tone at 1MHz offset. Experiment can for example increase the link SNR by using more antenna elements (i.e., 8 for TX and 8 for RX) via the PAAM API, and the corresponding results are shown in the right figure.

root@srv1-lg1:~/paam_api/examples# python3 setup_betaboard_v1.2.py -c ethernet -a rfdev2-1 --ic 1 -n 8 --txrx tx --pol h --dir 0 0
root@srv1-lg1:~/paam_api/examples# python3 setup_betaboard_v1.2.py -c ethernet -a rfdev2-2 --ic 2 -n 8 --txrx rx --pol h --dir 0 0

Finish the experiments

When the experiments are completed, make sure to turn off both PAAMs and see that the IC current consumption drops to the minimal values:

root@srv1-lg1:~/paam_api/examples# python3 reset_betaboard_v1.2.py -c ethernet -a rfdev2-1
...
Index   Name    ADC Volt.   Curr.
0   1v2 30  0.073   0.037
1   1v5 45  0.110   0.220
2   1v8 1   0.002   0.001
3   2v7_0   38  0.093   0.186
4   2v7_1   45  0.110   0.220
5   2v7_2   47  0.115   0.230
6   2v7_3   37  0.090   0.181
7   3v3_pll 57  0.139   0.070
8   5v_uzed 264 0.645   0.645
9   12v 106 0.259   0.863
10  0V  0   0.000   x
11  1V8 735 1.796   x
Closed port to Zynq
PAAM board shutdown...!!!

root@srv1-lg1:~/paam_api/examples# python3 reset_betaboard_v1.2.py -c ethernet -a rfdev2-2
...
Index   Name    ADC Volt.   Curr.
0   1v2 109 0.266   0.133
1   1v5 140 0.342   0.684
2   1v8 23  0.056   0.028
3   2v7_0   9   0.022   0.044
4   2v7_1   11  0.027   0.054
5   2v7_2   51  0.125   0.249
6   2v7_3   10  0.024   0.049
7   3v3_pll 115 0.281   0.141
8   5v_uzed 223 0.545   0.545
9   12v 99  0.242   0.806
10  0V  0   0.000   x
11  1V8 735 1.796   x
Closed port to Zynq
PAAM board shutdown...!!!
Last modified 3 weeks ago Last modified on Apr 13, 2021, 2:10:56 PM

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