Supporting over the air (OTA) angle of arrival (AOA) testing

Generating multiple single channel signals for broadcast

into anechoic chambers

GSS9790

Multi-Output Multi-GNSS

RF Constellation Simulator System

GSS9790

Multi-Output Multi-GNSS RF Constellation, Simulator System

For over the air (OTA) testing of antennas and devices

where angle of arrival (AOA) needs to be represented,

or as part of real-world time-synchronised indoor GNSS

implementation.

Spirent’s GSS9790 Multi-Output, Multi-GNSS RF Constellation

Simulator System is a development of the world’s most

advanced GNSS Constellation Simulator, the GSS9000.

The GSS9790 is a unique solution providing the core element

for GNSS applications that require a test system that can be

used in both conducted (lab) and radiated/OTA (chamber)

conditions.

Signicantly reducing the need to perform expensive eld

trials, it provides an accurate, repeatable, and controllable

tool—free of the constraints and security vulnerabilities

associated with operational or eld-test environments.

The GSS9790 is a full GNSS RF Constellation Simulator,

offering total user control over the satellite orbital denitions,

propagation and environmental conditions, signal and

data information, accurately modeling satellite trajectories

according to the user-dened simulation location, date, and

time.

When operated with Spirent’s SimGEN™ control software,

the user equipment under test behaves as if it were receiving

RF signals from real satellites, reporting manoeuvres and

trajectories according to the simulation input.

Standard features enabled by the simulation control and

scenario denition software, SimGEN™, include simulation of

multipath reections, terrain obscuration, antenna reception

gain patterns, differential corrections, trajectory generators

for land, air, sea and space vehicles, and comprehensive error

generation and system modelling. The product also accepts

user-supplied trajectories, either from a le or in real-time via a

remote control interface. This enables testing of hardware-in-

the-loop (HIL) applications and supports ultra-low latency and

high update rates—all whilst maintaining the full performance

specication.

The GSS9790 is ideal for testing any application that requires

independent access to the RF signals from each of the

simulated GNSS satellites.

Complete System Testing

The GSS9790 can be used as the signal generator attached

to multiple transmission antennas installed in an anechoic

chamber. The antennas are spatially distributed to present

the appropriate arrival vectors of the simulated satellite

signals at the antenna site. Interference sources can also be

located anywhere in the chamber to represent different test

environments.

By mounting the antenna on a rate table that replicates the

attitude changes of the simulated device, a comprehensive

evaluation of all aspects of the receiving system can be

achieved in a secure environment, free from unintentional

interference (both incoming and outgoing), and free from

external observation.

Again, using an anechoic chamber with radiating antennas, the

GSS9790 can provide spatial signal diversity for testing items

such as GNSS-equipped personal devices through the actual

antenna. Items such as reectors, signal attenuators (a dummy

human head for example) can be physically placed adjacent to

the unit under test to emulate real-world environments.

The GSS9790 Solution

The GSS9790 is essentially a modied variant of Spirent’s

GSS9000 multi-GNSS simulator platform.

A GSS9790 system consists of 1, 2, or 3 Signal Generator

Chassis and a dedicated C50r Host Unit running Spirent’s

SimGEN™ scenario denition and simulation control software.

Output Modes

Individual Output Mode

In individual output mode a signal representing each satellite

is available from each of the 10 outputs. In an OTA application

the individual outputs are connected to transmit antennas

located around the anechoic chamber ceiling representing

the approximate sky positions of the transmitting GNSS

satellites, with the DUT located at the centre (focal point) of

the chamber.

Composite Output Mode

In composite output mode the GSS9790 operates as a

standard GNSS constellation simulator. All GNSS signals are

presented to the single RF output representing the physical

phase centre point of the sky-interface of a GNSS device’s

antenna.

Signal Generator

Chassis

C50r Host

Test Scenario Enviroment

SimGEN™ GNSS Test Scenario Denition

and Control Software

The GSS9790 is controlled by SimGEN™ running on the

C50r Host. Spirent’s SimGEN™ software suite is the world’s

most capable and advanced GNSS simulation software and

provides an extensive range of simulation features that can be

used to congure and dene the required test scenario.

• Fully automatic and propagated generation of precise

satellite orbital data, ephemerides and almanac

• Proven models for authentic simulation

• Multiplicity of mechanisms for applying declared and

undeclared errors and modications to navigation data,

satellite clocks and orbits

• SimREMOTE: Comprehensive simulation control and

6-DOF trajectory delivery capability

• Data logging and streaming of signal, time, control,

vehicle and trajectory data over a variety of interfaces in

real-time and to le

• Range of models for multipath reections

• Terrain obscuration models

• Independent satellite/channel signal power control

• Signal modulation and code control

• Vehicle personalities and motion modelling for aircraft,

spacecraft, marine vessels and land vehicles

• Antenna reception gain and phase patterns

• Satellite transmit antenna pattern control

• Clock g-sensitivity

• Antenna lever arm effects

• INS aiding data

• Ionosphere and Troposphere effects including

ionospheric scintillation

• DGPS corrections

• Pseudorange ramps (for RAIM testing)

• Coherent and non-coherent Interference and noise

modelling (with optional GSS7765 Interference

Simulation System)

• Leap-second and week roll-over event testing

• Antenna Reception Patterns (Gain and Phase)—since the

real antenna is part of the test

• Vehicle motion—unless the DUT antenna can be

mounted on a rate table that is driven consummate with

the SimGEN™ scenario vehicle attitude dynamics

• Multipath denition—if the DUT antenna has Direction Of

Arrival capability—since transmit antenna locations are

xed

SimGEN

scenario

Supported Signals

Constellation Frequency

GPS L1, L2, L5

SBAS L1, L5

QZSS L1, L2, L5, L6

Galileo E1, E5, E6

GLONASS L1, L2

BeiDou-2 B1, B2

NavIC/IRNSS L5

RF Outputs

• 1 or 2 composite outputs, per simulator chassis, for

co-axial test applications

• 10 individual outputs, per GNSS constellation carrier

frequency, for anechoic chamber test applications

The system supports eld-upgrade to increase the number of

outputs.

Channels

• Up to 16 satellites simultaneously simulated at each

carrier at the composite output(s), for co-axial test

applications

• One satellite signal at one carrier at each individual

output, for anechoic chamber test applications

The system supports ﬁeld-upgrade to increase the number of

independent outputs.

For more information, call your Spirent sales representative or

visit us on the web at www.spirent.com/ContactSpirent.

www.spirent.com

and/or product names and/or logos referred to in this document, in particular the

name “Spirent” and its logo device, are either registered trademarks or trademarks

Specications subject to change without notice.

Americas 1-800-SPIRENT

+1-800-774-7368 | sales@spirent.com

US Government & Defense

info@spirentfederal.com | spirentfederal.com

Europe and the Middle East

+44 (0) 1293 767979 | emeainfo@spirent.com

Asia and the Pacic

+86-10-8518-2539 | salesasia@spirent.com

MCD00384 Issue 1-01 | RevB | 11/18

GSS9790

Multi-Output Multi-GNSS RF Constellation, Simulator System

Example Congurations:

GPS L1 x 10 channels + GPS L2 x 10 channels with classied

signals

GPS L1 x 10 channels + GPS L2 x 10 channels + GPS L5 x 10

channels with classiﬁed signals, 10-way combined

Capability and Performance—Key Attributes

• Up to 1000Hz Simulation Iteration Rate (SIR) and

Hardware Update Rate (HUR)

• 10 outputs per chassis, plus composite output

• 0.3mm RMS Pseudorange Accuracy

• <0.005 Rad RMS Phase Noise

• 120,000 m/s Relative Velocity, 192,600 m/s

Relative

Acceleration, 890,400 m/s

Relative Jerk (full

specication maintained under these dynamics)

• Highly exible congurations selectable via a ‘cabinet’ of

licence keys

• Complete portability of Spirent SimGEN™ scenarios

• In-eld upgradeability of principal GNSS functionality

and capability

• On-the-y re-conguration of constellation and signal

congurations