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GSS7725 Interference Generator User Manual
© Spirent Communications plc 2002-2017
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File
The name of the input IQ file that exists within the directory:
<path_to_posapp>/GSS7725/waveforms
The dropdown updates to the files present within the above directory with
the extensions .waveform or .bin
The format of the file should be, binary, 16 bit (2 byte) per sample,
interleaved I&Q (I0Q0I1Q1I2Q2…), big or little endian.
File sample frequency
The sample rate of the input File above, this can be selected as one of the
following:
4 MS/s
16 MS/s
26 MS/s
51.1 MS/s
120 MS/s
The default is 4 MS/s
File output frequency
The output sample frequency. The input file IQ will be up/down sampled
using interpolation to the output sample frequency 25 MS/s.
The output sample rate achievable is reliant upon the specification of the
controller machine that the GSS7725 controller software is running upon.
i.e. dedicated Ethernet with no other traffic, number and clock speed of
CPU cores, SSD vs HDD.
Reference clock
The internal reference clock has a frequency stability of 2.5 ppm. The clock
frequency stability can be increased by setting this value to “External” and
connecting the 10 MHz and 1 PPS from the GNSS signal generator to the
back of the GSS7725.
The default is Internal.
File endianness
The endianness of the input IQ file. This can be set to Big or Little. Big
implies that the first byte of data for each sample contains is the most
significant. Little implies that the first byte of data for each sample contains
the least significant.
Interferer RF on/off
Note: Specifying a customer waveform may also set the On/Off state of the Interference channel.
Use this command see Figure 12, to specify periods when the interference source is On at the
Action time you enter.
Figure 12 Command type – Interferer RF on/off
Action time
Set the days and time into the scenario you want to apply the
Command type
