: SX3 GNSS Software Receiver for R&D

Insights

SX3 GPS/GALILEO/GLONASS/BEIDOU/QZSS/IRNSS SOFTWARE RECEIVER

Real-time capable on COTS PC hardware when simultaneously tracking all current civil SIS signals of GPS, Galileo, GLONASS, BeiDou, QZSS, SBAS and IRNSS systems (using 8 IF input streams at a sample rate of 20 MHz each)
Adaptable configurations enabling real-time full featured reference station mode on COTS PC hardware
Recorder functionality to store data files for later post-processing
Entire configurability provided within the graphical user interface (including online configuration parameter description within GUI)
Live configurability for dedicated parameters as DLL, FLL and PLL bandwidths
Dedicated widgets for PVT solution, RF-spectrum, multi-correlator output, GNSS channel output, acquisition output, …

REAL-TIME MULTI-CORRELATOR

Continuous real-time visualization of the correlation function within Doppler and code domain or time and code domain for all tracked GNSS (BPSK, BOC, AltBOC) signals
User definable correlator spacing and integration times
Long multi-correlator integration times possible due to navigation-bit removal
Multipath and spoofing detection possible via analysis of correlation values
Data logging for post analysis provided

POST-PROCESSING DATA ANALYSIS

Data logging for intermediate data of various signal processing steps, e.g. acquisition data logs, channel dump logs (including NCO data, discriminator values and IQ data), decoded navigation data bits and much more
Additional MATLAB tools for further data analysis come along with the SX3 delivery
Standard outputs as RINEX 2.11 and RINEX 3

APPLICATION PROGRAMMING INTERFACE

C -language based SX3 API framework provided to implement user defined algorithms
User is free to add, replace or expand capabilities of the SX3 software receiver due to the access to receiver’s internal data
Seamless loading of user generated DLL files at receiver runtime (in real-time and post processing mode)
Full debug capabilities for users within their self defined source code
Due to DLL concept different partners can contribute to dedicated developments without any need to disclose the source code to each other

SIGNAL QUALITY MONITORING

Signal Quality Monitor to verify the shape of the correlation function
Signal Power Monitor to detect anomalous signals
Code Carrier Divergence Monitor to check code/carrier divergency
Measurement Quality Monitor performing pseudo-range measurement tests

DUAL RF-INPUT

Dual RF-input operation mode provided by IFEN’s SX3 hardware frontend including full integration within the SX3 software receiver
Attitude determination systems and reflectometry systems are available as options
User defined algorithm development for dual RF-input systems possible in conjunction with the API functionality

Benefits

IFEN's SX3 multi-GNSS software receiver tracks all known GNSS signals in view, in real-time on a standard laptop now and in the foreseeable future (up to 1000 channels in parallel on a core i7). The included RF-front end offers four RF frequency paths with 50 MHz bandwidth each, covering the entire GNSS L-band spectrum. The USB 3.0 interface enables high-speed data transfer with up to 8 bit quantization. Among other options a dual RF input front end is available as well. This can for example be used for attitude determination, reflectometry and other applications requiring the synchronized input from two antennas. An optional, built-in shock and vibration robust OCXO reference oscillator (MIL-STD 202G) is available, which replaces the standard high quality TCXO normally used.

The SX3 software offers the possibility to configure the data processing in multiple ways via the GUI. The user can for example change loop bandwidths, integration times, the main processing rate and choose between different correlation types. The software includes a multi-correlator providing a two-dimensional (Code and Doppler) correlation function visualization in real-time. Beside standard data output such as RINEX files, the SX3 offers several logging file types containing detailed data such as acquisition and correlation data output. The receiver comes with several powerful processing algorithms like vector tracking, to improve the tracking of weak signals in degraded environments, and poly-fit tracking to reduce measurement noise.

The SX3 can be configured to record the raw IF-samples, in parallel to the real-time processing, for later post-processing. The recorded IF-samples can then be repeatedly re-processed, enabling the comparison of different algorithms (conventional tracking, vector tracking etc.) and/or receiver parameters (e.g. loop bandwidths, different correlator types etc.).

For user algorithm development and testing the SX3 provides access to all the building blocks of the GNSS signal processing. This enables the user to implement and test her/his own tracking, acquisition and PVT algorithms. This functionality is provided through a flexible Application Programming Interface (API) enabling the user to replace or expand the capabilities of the software receiver with own algorithms. The API can be used in real-time as well as in post-processing and as a further added value the API provides access to receiver internal data to monitor the receiver operation.

APPLICATIONS

The SX3 is applicable in a wide field of different GNSS research areas. It is designed as a scientific tool, developed by leading scientists to meet their own, highly specific but widespread demands in their own research.
Our SX3 is a tool made by professionals for professionals.

Of course a number of clearly defined practical applications for the SX3 can be figured out:
Most of them are in the area of GPS / GNSS science as of the reason that its numerous strengths can best be made use of at the very edge of today’s GPS / GNSS signal receiver development.

Typical applications of the IFEN SX3 are

GNSS signal reflectometry (SX3 BE)
Heading (SX3 BE)
Antenna Diversity (SX3 BE)
Multipath signal evaluation
Ionospheric scintillation
Interference monitoring
Weak signal investigation (Indoor-GPS / GNSS) and sensor fusion
GNSS signal monitoring and data logging
Integration in GNSS reference stations

Documents

Data Sheet SX3 - Download