Flexiband USB Front-end

Flexible GNSS Front-end

Hardware-Aufbau des Front-ends mit Antenne
© Fraunhofer IIS/Heiko Wörrlein

Unser flexibles GNSS Front-end ermöglicht den Empfang und die Speicherung von Satellitensignalen auf bis zu drei Kanälen.

  • Portable USB 3.0 device
  • Supports all GNSS signals
  • 3 bands received simultaneously
  • Up to 80 MHz RF-BW @ 8 Bit I/Q
  • Multi-antenna support
  • User-friendly GUI and API
  • Our Flexiband USB Front-end can be purchased at our distribution partner TeleOrbit GmbH

 

 

Flexiband Triband L125 (III-1b extended) Configuration

The following Flexiband L125 III-1b configuration was used:

Configuration Frequency Band Bandwithd (MHz) Center Frequency (MHz) Intermediate Frequency (MHz) Sampling Rate (MHz) Sample Bit Withd USB data rate (MBit/s)
L125 III-1b L1/E1bc 18 1575,420 0 20 2x 4 (complex) 640
L2/L2C 18 1227,600 0 20 2x 4 (complex)
L5/E5a 38 1176,450 0 40 2x 4 (complex)

Spirent GSS8000 GPS/Galileo Signal Generator

Signalsimulatoren im Fraunhofer GALILEOLAB in Nürnberg
© Fraunhofer IIS
Spirent Szenario
© Fraunhofer IIS

Simulated Spirent GPS/Galileo scenario

Using a static scenario we recorded one 210 s and one 15 s long set of data using the previously described L125 Flexiband Configuration III-1b.

 

The multiplexed, raw data streams are available here (L125_III1b_15s.usb, L125_III1b_210s.usb). The description of the exact multiplexed data format will be provided in an updated version of this page. Please unzip before using.

The demultiplexed data streams were extended to an 8bit/sample I/Q format can be found here:

The following Matlab code example can be used to read in the raw, demultiplexed data, please unzip before using:

 


FS = 20e6;  % Sampling Rate for L1 / L2; FS = 40e6 for L5
freqIF = 0; % Same for L1, L2 and L5

NrOfSamples = 1e6;

fid = fopen(L125_III1b_15s_L1.bin', 'r');
A = fread(fid, NrOfSamples, 'int8'); % 8 bit / sample
fclose(fid);

data_i = A(1:2:end);
data_q = A(2:2:end);
input_cmplx=data_i + j*data_q;



Note that the I and Q components are Multiplexed: 8bit-I | 8bit-Q | ....

The simulated Spirent scenario is depicted in figure "Simulated Spirent GPS/Galileo scenario":

The exact simulated satellite information is available upon request.

Roof Antenna Fraunhofer IIS, Nuremberg

Antennen auf dem Dach des Fraunhofer IIS
© Fraunhofer IIS

Installation von Referenzantennen auf dem Institutsgebäude des Fraunhofer IIS

Moreover, 15 s and 210 s long raw data collections have been carried out with the same Flexiband unit and configuration using the roof antenna of Fraunhofer IIS. The filenames indicate the date/time when the data was collected.

The multiplexed, raw data streams are available here (20140923_20-15-55_L125_roof_15s.usb, 20140923_20-15-55_L125_roof_210s.usb). The description of the exact multiplexed data format will be provided in an updated version of this page.

The demultiplexed data streams were extended to an 8bit/sample I/Q format can be found here, please unzip before using:

Measurement Campaign, Hanoi, Vietnam

© TeleOrbit GmbH, Daniel Seybold

In a measurement campaign carried out in Hanoi, Vietnam, in October 2017, the Flexiband was used to record different sets of wideband L1/E1/G1/B1, L5/E5a and S-band signals, including the IRNSS on L5 and S-Band. The following one minute long sample file uses the configuration III-7a as described in the table below and in the 20171017_09-51-43_III-7a_short.zip (see link below the table) description according to the ION SDR Metadata standard.

The test and measurement campaign at the NAVIS centre in Hanoi, Vietnam, has been co-funded by the BELS Project (Building European Links toward South East Asia in the field of EGNSS). 

 

Configuration Frequency Band Bandwithd (MHz) Center Frequency (MHz) Intermediate Frequency (MHz) Sampling Rate (MHz) Sample Bit Withd USB data rate (MBit/s)
III-7a L1/E1abc/G1/B1 54 1580.000000

L1: -4.580

G1: 22.000

81 2x 4 (complex) 972
IRNSS-S 18 2491.250000 0.778000 20.25 2x 4 (complex)
L5/E5a 38 1173.546875 2.905000 40.5 2x 2 (complex)

License

All example files are provided under a “Creative Commons” BY- NC license:

http://de.creativecommons.org/

That means you are free to use these recorded files for non-commercial work while giving credit to Fraunhofer IIS and citing this website.