Brief Description of Vector Signal Analysis
R&S
®
FSV-K70
15
Operating Manual 1176.7578.02 ─ 09
In the baseband block diagrams (see
), the system-theoretical transmitter
and analyzer filters are shown for PSK and QAM demodulation. For the sake of clear-
ness, RF stages, IF filters and the filter stages of the
digital hardware section
are not
shown.
For a correct demodulation, the following filters have to be accurately specified for the
analyzer:
●
Transmit filter: filter characteristic of transmitter
●
Meas filter:
–
PSK, QAM, UserQAM, MSK:
The I and the Q part of the measurement and the reference signal are filtered
with this filter.
–
FSK:
The instantaneous frequency of the measurement reference signal are filtered.
In many applications, this filter is identical with the ISI filter.
The receive filter (ISI filter) is configured internally depending on the Transmit filter.
The goal is to produce intersymbol-interference-free points for the demodulation.
The reference filter synthesizes the ideal transmitted signal (after meas filtering). It is
calculated by the analyzer from the above filters (convolution operation
Transmit filter
* Meas Filter
).
Table 2-2: Typical combinations of Tx and Meas filters
Transmit filter
Measurement filter
(analyzer)
Remarks
RC (raised cosine)
-
filter combination without intersymbol
interference (ISI)
RRC (root raised cosine)
RRC
filter combination without ISI
GMSK
-
filter combination with low ISI
Linearized GMSK
EDGE NSR
standard specific filter; filter combina-
tion with ISI
Gauss
-
filter combination with low ISI
Rectangular
-
filter combination without ISI
Half Sine
-
filter combination without ISI
CDMA2000 1X FORWARD
Low ISI Meas Filter
filter combination without ISI
CDMA2000 1X REVERSE
Low ISI Meas Filter
filter combination without ISI
APCO25 C4FM
Rectangular
filter combination without ISI
APCO25 H-CPM
Rectangular
filter combination without ISI
APCO25 H-DQPSK
Low ISI Meas Filter
filter combination without ISI
APCO25 H-D8PSK Narrow
Low ISI Meas Filter
filter combination without ISI
APCO25 H-D8PSK Wide
Low ISI Meas Filter
filter combination without ISI
EDGE Narrow Pulse Shape
EDGE HSR (Narrow
Pulse)
standard specific filter; filter combina-
tion with ISI
Filters and Bandwidths During Signal Processing
Содержание FSV-K70
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