Instrument Function
R&S
®
SMBV100A
325
Operating Manual 1176.8016.02 ─ 17
Figure 5-17: Setting range for frequency offset
Example: Calculating the maximum frequency offset
This example uses the following signal:
●
"Standard = 3GPP FDD"
●
"Chip Rate = 3.84 Mcps"
●
"Filter Type = Root Cosine"
●
"Roll Off Factor = 0.22"
Figure 5-18: 3GPP FDD signal (chip rate 3.84 Mcps, root-cosine filter 0.22).
The complex useful bandwidth of filtered signal is calculated as follows:
f
use
= (1 + "Roll Off Factor") * "Symbol Rate"
f
use
= (1+ 0.22) * 3.84 MHz = 4.6848 MHz
For instrument with a total available I/Q bandwidth of 120 MHz, the valid range of val-
ues for the frequency offset is then:
-120MHz/2 + 4.6848MHz/2
≤
f
offset
≤
120MHz/2 - 4.6848MHz/2 or
-57.6576MHz
≤
f
offset
≤
57.6576MHz
Remote command:
Baseband Signal - Baseband Block