Rohde & Schwarz EVSG-B1, Руководство пользователя

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Data Management
R&S
®
EVSG1000
218 User Manual 1178.6227.02 ─ 06
Where:
●
<measmode> : the used measurement mode
●
<rx_board> : the used receiver board (rx1, rx2)
●
list<no.> : the used data list
● GPS Data Synchronization ................................................................................... 218
● I/Q Data Recording and Streaming (R&S EVSG1-K25) ........................................218
● Recording Settings ................................................................................................219
● Activating Data Recording .....................................................................................221
● Viewing Recorded Data ........................................................................................ 223
● Analyzing Recorded I/Q Data ................................................................................223
8.2.1 GPS Data Synchronization
Together with the measurement results, the GPS data at the time of signal input is also
stored, if available (see
Chapter 9.7, "GPS Configuration" , on page 240). Storing GPS
data is useful to synchronize specific measurement results with the precise time and
location of the input signal. However, signal transmission via the RS232 serial connec-
tion can cause delays in the stored GPS time as opposed to the actual time of input.
Therefore, it is useful to synchronize the stored GPS data to the PPS signal also provi-
ded by the GPS receiver.
8.2.2 I/Q Data Recording and Streaming (R&S EVSG1-K25)
Optionally, the raw, unprocessed I/Q data can also be stored with the data recording. In
this case, the I/Q data is stored as a separate file with the same file name as the data
list, but the extension
.iq
. This feature requires the R&S EVSG1-K25 option.
I/Q data is stored with a sample rate of 125000 samples per second. I and Q values
are stored with 32 bit each, in little endian and signed integer format. The I/Q data level
is aligned to the RF input signal of the R&S
EVSG1000. That is: 0 dBm correspond to
a magnitude value of 0x10000000 (hexadecimal). Each sample requires 8 bytes of
storage, which adds up to 1
MB per second. The I/Q data files can become very large.
After 33 minutes, they exceed 2 GB, meaning they can no longer be stored on a FAT-
formatted USB storage device. In this case, you require a storage device with a linux
file system, e.g. ext4. Also consider the limitations of the internal storage device. When
using two RX boards simultaneously, the storage is filled up twice as quickly.
I/Q data can also be streamed during the measurement using the LAN interface of the
R&S
EVSG1000 (TCP port 8001 (RX1) or 8002 (RX2)). Simply connect a TCP/IP client
to the port and the data is streamed immediately. The format is the same as for record-
ing.
Example:
netcat 172.23.226.22 8001 > File1.iq
Starts streaming I/Q data from the RX1 input to a file named
File1.iq
.
Recording Measurement Data