SOLUTION
BROCHURE

Open Architecture forRadar and EW Researchni.comSOLUTION BROCHURE

Open Architecture
for Radar and EW
Research
03 Trends in Radar
04 Trends in Electronic Warfare

05 Reference Architecture Overview
07 Solution Details
09 NI COTS Hardware Components
11 Validated Third-Party COTS Components
12 Software Components

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OPEN ARCHITECTURE FOR RADAR AND EW RESEARCH

3

Trends in Radar
Radar systems are experiencing considerable technology disruption because of the rapidly changing
electromagnetic battlespace. Active electronically scanned arrays, ultra-wideband technology, andcognitive radar systems present new design and test challenges for even the most experienced
organizations.

Rapidly Prototype Radar Waveforms and Architectures
Threats and countermeasures continue to evolve at a rapid pace. Today, radar must track agile, hypersonic
weapons, resolve swarms of drones, and detect low-RCS aircraft. Radar system developers are expected
to prototype new concepts quickly, such as cognitive techniques or fully digital beamforming, to counteract
emerging threats, increase performance and capability, and assure operation in contested EM
environments. COTS software defined radios (SDRs) with an integrated software workflow help accelerate
the transition from concept to testbed to deployed system.

FIGURE 01
Northrop Grumman E-2D Advanced Hawkeye: Airborne Early Warning Command and Control“Using COTS equipment greatly reduced our efforts to design complex
radar systems. We could focus more on DSP rather than on designing RF
I/O over and over again.”
Dr. Piotr Samczyński
Warsaw University of Technology Institute of Electronic Systems

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4

Trends in Electronic Warfare
Spectrum superiority has never been more critical to success on the battlefield. Amid an increasingly
contested and congested electromagnetic spectrum, the ability to reliably operate communications andnavigation systems while deceiving and disrupting the adversary creates a significant tactical advantage.
Software defined radio (SDR) provides the ideal platform for developing and deploying electronic warfare
systems and the flexibility to adapt to modern and constantly evolving threats. COTS technology is ideal forsystem-level test of complex, intelligent EW receivers, reducing the need for flight test hours by modelingand simulating a multi-emitter environment.

Electronic Attack

Electronic Protection

Electronic Support

Be disruptive. Use COTS
SDR to rapidly design anddeploy systems that denyhostile access to theelectromagnetic spectrum,such as communications
jamming and counter-UAS
systems.

Be resilient. Prototype
systems capable of assured
operation in a contested andcongested electromagnetic
spectrum with techniques likecognitive radio and frequency
hopping.

Be aware. Deploy wideband,
multi-channel acquisition
systems with robust
connectivity capabilities that
support multi-domain
operational and situationalawareness through signals
intelligence and direction
finding.

FIGURE 02
The electromagnetic battlefield is ever more contested and congested with radar,
communications, navigation, and electronic warfare systems.

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5Reference Architecture Overview
The Open Architecture for Radar and EW Research is NI’s blueprint for a system that meets key
requirements of a hardware testbed for prototyping novel radar and EW technology. Follow NI’s
recommended solution to build up a multi-channel radar/EW research system as quickly as possible; thisreference architecture has been validated by NI engineers to ensure it delivers the specified performance.
Based on COTS Hardware and open-source software, this solution is ideal for rapidly transitioning radar IP
through its development lifecycle: from software simulation to proof-of-concept demonstration to tactical
deployment.

Architectures for Multichannel Radar/EW Research and Prototyping
Modern radar systems incorporate capability including cognitive function, multi-channel operation,and machine learning / artificial intelligence. To prototype novel capability for such systems, systems
engineers and researchers must quickly develop a testbed for evaluating new ideas. The NI hardware
platform provides key capabilities for radar and EW research.

FIGURE 03
Radar researchers can focus more on their novel front end or DSP when the RF I/O, processing
modules, and data movement infrastructure are provided by COTS components.

ni.comOPEN ARCHITECTURE FOR RADAR AND EW RESEARCH

6Multichannel Systems
For accurate ranging and positioning of targets, it is necessary for the transmit (Tx) and receive (Rx)chains of a radar system to be synchronized. For multi-channel systems, this becomes yet more
important since multiple Tx and Rx chains must be synchronized across an array. NI COTS modular
instruments based on the PXI platform provide phase coherency via the sharing of local oscillators,
reference clocks, sampling clocks, and triggers.

Data Streaming
Wide bandwidth I/Q data necessitates high throughput streaming interfaces. NI provides users withaccess to FPGA multigigabit transceivers (MGTs) to avoid bottlenecks in moving data from I/O toprocessing.

Digital Signal Processing (DSP)
Novel capability such as spectral interference avoidance, clutter suppression, and automatic target
recognition requires inline processing of radar return signals. NI incorporates Xilinx FPGAs onboard
instruments like Vector Signal Transceivers and FlexRIO. This allows engineers and researchers to
execute calculations like space-time adaptive processing (STAP), constant false alarm rate (CFAR), andbeamforming with hardware-level latency and performance.

Machine Learning / Knowledge-Aided Computing
Today’s cognitive radar system operates differently from yesterday’s. And tomorrow’s will operate
differently from today’s. That’s because cognitive radars are constantly learning and evolving, adapting to
new targets, new countermeasures, and new channel conditions. Machine learning algorithms make thispossible, and so NI provides interfaces to CPU and GPU-based compute servers via PCI
Express, 100 GbE, and Xilinx Aurora, to enable cognitive capability.

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Solution Details
A Validated Design Pattern
For this reference architecture, NI has selected a configuration of software-connected COTS hardware from
NI and third parties that satisfy the requirements of a radar/EW testbed. Furthermore, NI has implemented
a fully operational 32-channel system and measured its performance. The following resources are freely
available to users of the reference architecture:• Complete bill of materials including rack, cables, and other hardware required for system assembly• User manual including system assembly instructions and measured specifications• Reference software, built upon an open-source stack, that demonstrates control of the system

System Overview

FIGURE 04
The Open Architecture for Radar and EW Research provides the hardware, software, anddocumentation that accelerates path from concept to prototype

ni.comOPEN ARCHITECTURE FOR RADAR AND EW RESEARCHKey Specifications & Features
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Direct conversion RF sampling
Up to 200 MHz instantaneous bandwidth per channel
3 MHz – 6 GHz total RF frequency coverage
Phase coherent operation via shared local oscillator, PPS, and 10 MHz reference clock signals
Scalable multi-channel architecture
Controlled with open-source software
Up to 33.33 MSp/s on 32 channels simultaneously streaming data to disk or memory
CPU and FPGA processing nodes
Open PCIe slots for user customization
Ideal for both over-the-air (OTA) and cabled operation

FIGURE 05
Example Testbed With Server and USRPs Installed

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OPEN ARCHITECTURE FOR RADAR AND EW RESEARCH

9NI COTS Hardware Components
USRP N320 and N321 Software Defined Radios
The USRP N320 and N321 are networked software defined radios that provide reliability and fault-tolerance
for deployment in large scale and distributed wireless systems. They are high-performance SDRs that use
a unique RF design by Ettus Research to provide 2 Rx and 2 Tx channels in a half-wide RU form factor.
Each channel provides up to 200 MHz of instantaneous bandwidth, and covers a frequency range from 3
MHz to 6 GHz. The baseband processor uses the Xilinx Zynq-7100 SoC to deliver a large user
programmable FPGA for real-time, low latency processing and a dual-core ARM CPU for stand-alone
operation.
Support for 1 GbE, 10 GbE, and Aurora interfaces over two SFP+ ports and 1 QSFP+ port enables highthroughput IQ streaming to a host PC or FPGA coprocessor. A flexible synchronization architecture withsupport for LO sharing for TX and RX, 10 MHz clock reference, PPS time reference, GPSDO, and White
Rabbit enables implementation of phase coherent MIMO configurations. The USRP N320/1 leverages
recent software developments in UHD to simplify control and management of multiple devices over the
network with the unique capability to remotely administrate tasks such as debugging, updating software,rebooting, resetting to factory state, and monitoring system health.
The USRP N321 features 2 four-way power splitters for distributing an LO signal to other USRP N32x units
in a multi-USRP system.

FIGURE 06
In NI’s Open Architecture for Radar and EW, the USRP N32x SDRs provide RF front ends, I/O,
LO synthesis, power splitters for distributing LO, as well as an available FPGA processing nodeni.comOPEN ARCHITECTURE FOR RADAR AND EW RESEARCH

10

CDA-2990 Clock Distribution Device with GPSDO (OctoClock-G)
The CDA-2990 is an 8-Channel, 10 MHz Clock Distribution Device that helps you synchronize systems that
include USRP Software Defined Radio Devices. It accepts both external 10 MHz and pulse-per-second(PPS) input signals and amplifies and distributes the signals to eight output ports. The CDA-2990 isavailable in a configuration for distributing externally supplied signals. In the Open Architecture for Radarand EW Research, NI recommends the GPS-disciplined oscillator (GPSDO)-enabled option, which
integrates a GPS-disciplined oven-controlled crystal oscillator (OCXO) that generates the 10 MHz and PPS
signals internally.

FIGURE 07
The CDA-2990 provides clock synchronization to a network of USRP N32x SDRs

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Validated Third-Party COTS Components
The Open Architecture for Radar and EW Research incorporates hardware from third-party vendors. The
following system components have been validated and are recommended for up to 32-channel systems.

ServerDirectly stream large volumes of data from a multi-USRP system to a compute server to assess novel
cognitive radar algorithms. A server with many available PCIe slots offers users the flexibility to insert
GPUs for improved real-time processing power, additional SSDs, or additional network interface cards toincrease channel count.
Supermicro 4124GS-TNR—Server with dual AMD EPYC™ CPUs and 10 PCIe Gen 4 x16
slots. Numerous PCIe lanes from the CPU support many 10 GbE connections and the PCIe processing
required for high-channel-count systems.
Trenton Server—Server with dual 3rd generation Intel® Xeon® Ice Lake processors, 11 Gen 4.0 PCIeslots (5 x16 slots, 6 x8 slots), and 24x DDR4-3200 ECC RDIMM slots for high-channel-count systems.

Network Interface Cards (NICs)
Network Interface Cards allow USRPs to stream data to a server over 10 GbE links.
Intel® X710-DA4—supports x4 10 GbE connections.
Intel® E810-CQDA2—supports x2 100 GbE connections, or, with a breakout cable, x8 10 GbE
connections.

High Performance Data Storage
High volume and speed are necessary for writing wide bandwidth I/Q data to disk for post-processing or
playback. NI recommends using SSD drives in a RAID 0 configuration to achieve high data read and write
speeds.
HighPoint SSD7505—PCIe carrier board that holds x4 M.2 drives and supports either a software or
hardware RAID configuration.
Sabrent 2TB Rocket 4 PLUS—NVME M.2 SSD drive that supports consecutive write rates of morethan 6 GB/s.

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12SoftwareUtilize a validated open-source software stack to set up, synchronize, and control radar systems built
following the Open Architecture for Radar and EW research. Find prebuilt example code for controlling thereference architecture, as well as system setup documentation here:
https://github.com/EttusResearch/refarch-multich

Multichannel RF Reference Architecture
In the Open Architecture for Radar and EW Research GitHub repository, NI provides a library of functions
for configuring and controlling a network of multiple USRPS, as well as reference examples that utilize thelibrary to demonstrate highly synchronized transmission and receiving on multiple channels. These
examples have been validated by NI for up to 32 Transmit x 32 Receive channels and allow for scaling toeven higher channel count systems. The library and example are written in C++ and make use of the UHD
and RFNoC APIs.

UHD APIThe USRP Hardware Driver™ (UHD) software API supports application development on all USRP SDR
products. Using a common software interface is critical as it increases code portability, allowing
applications to transition seamlessly to other USRP SDR platforms when development requirements
expand or new platforms are available. UHD also offers cross-platform support for multiple industry
standard development environments and frameworks, including RFNoC, GNU Radio,
LabVIEW, MathWorks MATLAB® software, and MathWorks Simulink® software.
In the Open Architecture for Radar and EW Research reference software, UHD is used to transport user
waveform samples to and from USRP hardware as well as control various parameters (e.g., sampling
rate, center frequency, gains, etc.) of the radio. UHD GPP driver and firmware code is written in C/C++
while the code developed for the FPGA is written in Verilog. The majority of the UHD code base is open
source, including code that executes on the host, as well as code targeted to the USRP FPGA.

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FIGURE 08
Components of the USRP Hardware Driver (UHD)

RFNoC API
RFNoC is a network-distributed heterogeneous processing tool with a focus on enabling FPGA processing
in USRP devices. It allows you to move data on and off of an FPGA in a transparent way, thus enabling
seamless use of both host-based and FPGA-based processing in an application. It provides a way toleverage FPGA processing capabilities and IP in your application, which can scale across multiple FPGAs
and devices across a network. The Open Architecture for Radar and EW Research reference software
utilizes the RFNoC API to connect, synchronize, and control the system of USRPs. Utilizing RFNoC, sample
signals can be loaded onto the USRPs and transmitted.

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