SX3 GPS/Galileo/Glonass/Beidou/IRNSS Software Receiver

  • Real-time capable on COTS PC hardware when simultaneously tracking all current civil SIS signals of GPS, Galileo, GLONASS, BeiDou, 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

      Geodetic quality measurement

          • Geodetic quality measurement accuracy (code and carrier pseudorange accuracy follows the mathematical optimality criterions)
          • Exploitation of the super-high-bandwidth Galileo AltBOC signal. Code pseudorange noise at centimetre level

              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

                  Multipath Mitigation

                        • Multipath estimating discriminators implemented within the SX3 software
                        • Real-time GUI feedback for the number of estimated multipath paths
                        • Verified high coordinate measurement accuracy
                        • Continuous long term operation possible in SX3 reference station mode


                              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.


                              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. 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.

                              Therefore 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



                              Signal Capability

                              • GPS L1, L2P & L2C, L5 and SBAS L1
                              • Galileo E1, E5a, E5b (incl. AltBOC) and E6
                              • GLONASS G1, G2
                              • BeiDou B1, B2

                              • IRNSS L5/S-band


                              Flexible and Extendible
                              • Real-time and post-processing capabilities
                              • GNSS signal upgradeability by SW license

                              Application Programmers Interface
                              • IF-Sample logging API (baseline)
                              • Navigation API (baseline)
                              • Sensor data injection API (optional)
                              • Baseband acquisition & tracking API (optional)
                              • Assistance API (optional)

                              Release Notes