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Agilent N518xA, E8663B, E44x8C, and E82x7D Signal Generators Programming Guide 323
Creating and Downloading User-Data Files
FIR Filter Coefficient Downloads (N5182A, E4438C and E8267D)
The sampling period (Δt) is equal to the inverse of the sampling rate (FS). The sampling rate is equal
to the symbol rate multiplied by the oversample ratio. For example, the GSM symbol rate is
270.83 ksps. With an oversample ratio of 4, the sampling rate is 1083.32 kHz and Δt (inverse of FS)
is 923.088 nsec.
Downloading FIR Filter Coefficient Data
The signal generator stores the FIR files in the FIR (/USER/FIR) directory, which utilizes non-volatile
memory (see also “Signal Generator Memory” on page 281). Use the following SCPI command line to
download FIR filter coefficients (file) from the PC to the signal generator’s FIR directory:
:MEMory:DATA:FIR <"file_name">,osr,coefficient{,coefficient}
Use the following SCPI command line to query list data from the FIR file:
:MEMory:DATA:FIR? <"file_name">
Sample Command Line
The following SCPI command will download a typical set of FIR filter coefficient values and name the
file “FIR1”:
:MEMory:DATA:FIR "FIR1",4,0,0,0,0,0,0.000001,0.000012,0.000132,0.001101,
0.006743,0.030588,0.103676,0.265790,0.523849,0.809508,1,1,0.809508,0.523849,
0.265790,0.103676,0.030588,0.006743,0.001101,0.000132,0.000012,0.000001,0,
0,0,0,0
FIR1 assigns the name FIR1 to the associated OSR (over sample ratio) and coefficient
values (the file is then represented with this name in the FIR File catalog)
4 specifies the oversample ratio
0,0,0,0,0,
0.000001,... the FIR filter coefficients
Selecting a Downloaded User FIR Filter as the Active Filter
NOTE For information on manual key presses for the following remote procedures, refer to the
User’s Guide.
FIR Filter Data for TDMA Format
The following remote command selects user FIR filter data as the active filter for a TDMA modulation
format.
:RADio:<desired format>:FILTer <"file_name">
This command selects the user FIR filter, specified by the file name, as the active filter for the TDMA
modulation format. After selecting the file, activate the TDMA format with the following command:
:RADio:<desired format>:STATe On