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Using SystemVue's Radar Library
to Generate Signals for Radar Design
and Verification
Application Note
1.0 Introduction
Modern radar systems use more complex signal formats working in wide or
ultra-wide bandwidths, and operating in different frequencies (e.g., X, Ku and Ka
bands). They also use advanced digital signal processing techniques to disguise
their operation and overcome strong clutter and jamming in their environment.
Addressing this complexity requires the generation of realistic test signals and
system-level scenarios that can be used to create and verify the radar signal
processing algorithms. While dedicated hardware simulators and field testing
are typically used to generate these test signals, both are costly, time consuming
and apply later in the design process. This application note presents a less
expensive option for generating test signals early in system development. This
approach to system-level design and verification uses the Agilent SystemVue
environment, a Radar Model Library and commercial off-the-shelf test equipment
for generation of continual and pulse radar waveforms, for both algorithm and
hardware verification.
2.0 Design Problem
Radar signal processing algorithms play a critical role in advanced radar,
especially high-performance multi-mode systems. Radar designers require
custom reference waveforms with precise amounts of impairment and field
conditions when testing or verifying radar components (both baseband and RF).
The signal scenarios are used both for troubleshooting and block-level diagnostics,
as well as for initial platform integration and validation.
Unfortunately, signal processing algorithm creation is complicated, with all
resulting algorithms needing to be verified in the complex external environment.
Greater interaction between algorithms and signal sources provides a realistic
radar environment that allows early maturity and confidence in the radar sys-
tem. Creating the advanced algorithms therefore, requires the availability of a
sufficient set of models for the various radar elements and functions, including
signal generation, transmission, antenna, T/R switching, clutter, noise, jamming,
receiving, signal processing, and measurements.
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3.0 Common Approaches to Radar System Design
The two methods commonly employed by radar designers to generate the
required signals for algorithm creation are accelerated, dedicated hardware
simulation and direct field testing.
3.1 Hardware simulation
Scenario-based verification is typically performed using expensive, high-end
hardware simulators that create real-time scenarios of realistic fidelity.
Unfortunately, such simulators are not available early enough in the design
process (during the algorithm stage prior to hardware implementation), to
provide meaningful insight for the algorithm developer. They also don't integrate
well with model-based design practices or provide the level of scripting needed
in early development for low-level, block-level verification. Because simulation
takes place later in the design cycle, making design changes at this stage can
be both costly and time consuming. Design engineers can benefit from earlier
algorithmic validation of their key ideas.
3.2 Field testing
Another way to generate the required signals is to physically go into the field
to make environmental measurements of the radar hardware operating under
realistic conditions. While there are many reasons for utilizing this approach,
because it comes late in the design process it rarely connects to the original
algorithmic development environment. In addition, this method is costly,
sometimes inconvenient and time consuming.
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4.0 A More Practical, Less Expensive Option
For early development, a robust and inexpensive alternative uses a
convenient software simulation-based radar library to generate the reference
waveforms needed for radar signal processing algorithm development. Early
access to these signals enables the design of superior system architectures
and facilitates early hardware verification at different layers of abstraction, as
the model-based design matures.
4.1 The Agilent radar library application
As can be seen from Table 4-1, the Agilent W1905 Radar Model Library is an
advanced simulation block set of over 35 highly-parameterized primitive blocks
and higher-level reference designs. It can be used for modeling different types
of radar systems, creating radar signal processing algorithms, evaluating
system's performance and providing proof-of-concept designs. The block set
and its example workspaces serve as algorithmic and architectural reference
designs to verify radar performance under different conditions. These include
target and radar cross section (RCS) scenarios, clutter conditions, jamming
(intentional) and environmental interference, and the effect of various receiver
algorithms. It is ideal for radar designers who need to generate precise signals
for algorithm and hardware verification, or study the performance of their radar
systems under various conditions.
Table 4-1. The W1905 radar model library block list
Signal LFM