R&S FSV-K70, Руководство пользователя

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Brief Description of Vector Signal Analysis
R&S
®
FSV-K70
11 Operating Manual 1176.7578.02 ─ 09
an integral factor). An equalizer filter before the resampler compensates for the fre-
quency response of the analyzer's analog filter stages which would otherwise add to
the modulation errors.
During operation, the filters and decimation factors of the instrument are set so that a
sample frequency is obtained at the output of the
decimation stage, which exactly cor-
responds to the following equation:
Sample rate = Symbol rate * Capture Oversampling (see "Capture Oversampling"
on page 154)
The complex output signal of the decimation stage is stored in the I/Q memory
( record buffer ) and forwarded to a signal processor (DSP) for further processing.
2.1.2 Block Diagram for Digital Baseband Input
The following block diagram provides an overview on how digital baseband input is
processed in the R&S
FSV-K70 option. The digital baseband input requires option
R&S FSV-B17.
Figure 2-2: Block diagram of digital hardware for digital baseband input (B17) in vector signal analy-
sis
The digital I/Q data stream is fed into the analyzer via the connector of the digital base-
band interface (R&S
FSV-B17 option). There is no need to equalize any IF filter or mix
the signal into the complex baseband. The digital hardware just has to ensure that the
final I/Q data stored in the record buffer has the correct sample rate; therefore, the sig-
nal is resampled and filtered.
2.2 Filters and Bandwidths During Signal Processing
This section describes the used filters in vector signal analysis with an R&S FSVA/
FSV, as well as the bandwidth after each filter.
The relevant filters for vector signal analysis are shown in Figure 2-3 .
Filters and Bandwidths During Signal Processing