R&S WinIQSIM2 Software Manual - Rohde & Schwarz

R&S ® WinIQSIM2
Graphical User Interface
Baseband Block
the filter characteristic changes form the passband to the stopband, where the signal is
completely suppressed.
Roll Off Factor
The roll off factor is a measure for the excess bandwidth compared to the ideal bandwidth
of a "brick like" filter. The roll off factor affects the steepness of the filter flanks. A "Roll
Off Factor" = 0 would result in the steepest flanks theoretical possible; values near to 1
make the flanks more flat.
Passband
The passband describes the frequency span that the filter passed unchanged. The total
passband of a filter is given as follow:
Bandwidth = (1 + "Roll Off Factor") * "Symbol Rate"
Cut Off Frequency Shift
The "Cut Off Frequency Shift" affects the cut off frequency in the way that the filter flanks
are "moved" and the passband increases by "Cut Off Frequency Shift"*"Sample Rate":
Cut Off Frequency = (1 + "Cut Off Frequency Shift") * "Sample
Rate"
●
●
A "Cut Off Frequency Shift" = -1 results in a very narrow-band filter
Increasing the value up to 1 makes the filter more broad-band
Software Manual 1008.0858.42 ─ 10
61