Flexiband USB Front-end

Flexible GNSS Front-end

Hardware-Aufbau des Front-ends mit Antenne
© Foto 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:

Frequ
ency band

Band

width

Center freq

Inter-mediate frequ
ency

Sampling rate

Sample
 bit width

 

USB data rate

[MHz]

[MHz]

[MHz]

[MHz]

[MBit/s]

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

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.

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

Simulated Spirent GPS/Galileo scenario

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

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.

Antennen auf dem Dach des Fraunhofer IIS
© Foto Fraunhofer IIS

Installation von Referenzantennen auf dem Institutsgebäude des Fraunhofer IIS

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:

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.