mmWave OFDM based ISAC

Description

This tutorial demonstrates how to perform an mmWave OFDM based ISAC (Integrated Sensing and Communications) experiment using the COSMOS testbed.

1. mmWave OFDM based ISAC
   1. Description
   2. Prerequisites
   3. Related COSMOS Documentation
   4. Resource Requirements
   5. Setup
   6. Execution
      1. Radar Side (srv1-lg1)
         1. Calibration
         2. Radar Transmission
      2. Mobile PAAM Receiver Side (mob4-1)

Prerequisites

• COSMOS account and reservation established
• Access to the radar SDR nodes and PAAM mobile node
• Chrome Remote Desktop for graphical access

Related COSMOS Documentation

• SDR and Wireless
• IBM 28-GHz Phased Array Board For COSMOS
• Chrome Remote Desktop Setup Page

Resource Requirements

• SDRs: sdr1-radar, sdr2-radar
• PAAMs: rfdev-sdr1-radar, rfdev-sdr2-radar
• Mobile PAAM: mob4-1
• Server: srv1-lg1
• Image: ubuntu2004-uhd4.3-gr3.8-radar.ndz

Setup

Load the required images onto the server and mobile PAAM:

omf load -i ubuntu2004-uhd4.3-gr3.8-radar.ndz -t srv1-lg1
omf load -i ubuntu2004-uhd4.3-gr3.8-radar.ndz -t mob4-1

Power on the experiment hardware:

omf tell -a on -t sdr1-radar,rfdev-sdr1-radar,sdr2-radar,rfdev-sdr2-radar,mob4-1,srv1-lg1

Connect to the server:

ssh root@srv1-lg1

Run the PAAM setup script:

cd IBM_PAAM_Software_vFINAL/examples/
python3 paam_radar_setup.py

Connect via Chrome Remote Desktop and choose the first GNOME on Xorg.

Execution

Radar Side (srv1-lg1)

Terminal 1: Network and packet generator configuration:

sudo ip link set dev eno1 mtu 9000
sudo sysctl -w net.core.wmem_max=25000000
O-JRC/examples/build-mimo-ofdm-packet-generator-Desktop-Debug/mimo-ofdm-packet-generator

Configure signal parameters:

• Sample Rate: 100 MHz
• Packet size: 50 bytes
• TX Antennas: 2

Press Start once configured.

Terminal 2: GNU Radio Execution

Execute the following command to launch GNU Radio Companion

gnuradio-companion

Calibration

Open the calibration flowgraph:

• O-JRC/examples/usrp/V0_JRC_calibration.grc

Verify calibration parameters:

• Variables
  • usrp_freq: 3e9
  • samp_rate: 100e6
• usrp_mimo_trx
  • Number of MBoards: 2
  • Number of TX: 2
  • Number of RX: 2
  • USRP Arguments: "addr0=10.38.24.1, addr1=10.38.24.2, master_clock_rate=200e6"
  • Clock Sources: "internal,external"
  • Time Sources: "internal,external"

Execute the flowgraph, set the TX Gain to 20dB and adjust the following parameters until waveforms are aligned:

• RX2 Gain
• RX2 Phase

Record these calibration values and terminate flowgraph.

Radar Transmission

Open TRX flowgraph:

• O-JRC/examples/usrp/V1_JRC_TRX.grc

Verify calibration parameters:

• Variables
  • usrp_freq: 3e9
  • samp_rate: 100e6
  • rf_freq: 28e9

Update defaults for:

• amp_rx2 = calibrated gain
• phase_rx2 = calibrated phase

Run radar transmission.

Mobile PAAM Receiver Side (mob4-1)

Open a terminal and execute the following to configure the network and the mobile PAAM:

curl "http://am1.orbit-lab.org:5054/array_mgmt/configure?dev_name=rfdev-mob4-1.sb1.cosmos-lab.org&ics=all&num_elements=16&txrx=rx&pol=h&theta=0&phi=0"

Launch GNU Radio Companion:

gnuradio-companion

Open RX Flowgraph:

• O-JRC/examples/usrp/V1_JRC_RX.grc

Check parameters:

• Variables
  • usrp_freq: 3e9
  • samp_rate: 100e6
  • rf_frequency: 28e9
• UHD Source
  • Device Address: "serial=31557B9,master_clock_rate=200e6"
  • Device Arguments: "resource:RIO0"
  • Mb0: Subdev Spec: "A:0"

Execute the flowgraph and set the RX Gain to 0dB to receive the OFDM data.