Basics on I/Q Data Acquisition and Processing
R&S
®
FSWP
19User Manual 1177.5856.02 ─ 07
4 Basics on I/Q Data Acquisition and Pro-
cessing
Some background knowledge on basic terms and principles used when describing I/Q
data acquisition on the R&S FSWP in general, and in the I/Q Analyzer application in
particular, is provided here for a better understanding of the required configuration set-
tings.
The I/Q Analyzer provides various possibilities to acquire the I/Q data to be analyzed:
●
Capturing analog I/Q data from the "RF Input" connector
●
Importing I/Q data from a file
Background information for all these scenarios and more is provided in the following
sections.
● Processing Analog I/Q Data from RF Input.............................................................19
● Basics on Input from I/Q Data Files........................................................................ 25
● Receiving and Providing Trigger Signals................................................................ 26
● I/Q Data Import and Export..................................................................................... 27
● Basics on FFT.........................................................................................................28
● I/Q Analyzer in MSRA Operating Mode.................................................................. 34
● Measurements in the Time and Frequency Domain............................................... 35
4.1 Processing Analog I/Q Data from RF Input
Complex baseband data
In the telephone systems of the past, baseband data was transmitted unchanged as an
analog signal. In modern phone systems and in radio communication, however, the
baseband data is modulated on a carrier frequency, which is then transmitted. The
receiver must demodulate the data based on the carrier frequency. When using mod-
ern modulation methods (e.g. QPSK, QAM etc.), the baseband signal becomes com-
plex. Complex data (or: I/Q data) consists of an imaginary (I) and a real (Q) compo-
nent.
Sweep vs sampling
The standard Spectrum application on the R&S FSWP performs frequency sweeps on
the input signal and measurements in the frequency and time domain. Other applica-
tions on the R&S FSWP, such as the I/Q Analyzer, sample and process the individual I
and Q components of the complex signal.
I/Q Analyzer - processing complex data from RF input
The I/Q Analyzer is a standard application used to capture and analyze I/Q data on the
R&S FSWP. By default, it assumes the I/Q data is modulated on a carrier frequency
and input via the "RF Input" connector on the R&S FSWP.
Processing Analog I/Q Data from RF Input
To Next Page
Loading...
