Application Example: GSM AM Suppression Test
R&S
®
SMW-K550
16
User Manual 1178.3263.02 ─ 01
Consider to load you own data lists and to configure the GSM bursts and frames
according to the specification
TS 51.021
.
The example assumes the following settings:
●
3x1x1 configuration with duplicated streams; generated are 6 streams, where 5 of
them are used
●
The 4 wanted signals are routed to RF A; the interfering signal to RF B (dynamic
range reasons)
●
The maximum RF BS Bandwidth is 24 MHz
●
The absolute radio frequency channel number that needs to be tested is ARFCN
30; the BS center frequency is f
DL
= 941 MHz
●
The frequency of the interfering signal (f
i
) is at least 6 MHz away form the ARFCN
under test.
The interfering signal uses the frequency f
i
= 947.2 MHz
●
The wanted signals are arranged symmetrically around the center frequency, see
Figure 4-2
The inner two wanted signals are at
±
6 MHz offset and the outer two at
±
12 MHz
●
GSM transmission in timeslot 1 for both, the 4 wanted and the interfering signals
●
The interfering signal is a GSMK modulated PN9 sequence of 511 bits length.
●
The DUT is multi-carrier BS with a multi-carrier receiver. Assumed is a simultane-
ous test of two logical channels on different carriers.
The generated wanted signals are pairwise identical. The streams of each pair are
frequency shifted so that their transmission is not on nearby carriers.
How to generate a 3x1x1 SISO signal with 6 output streams
1. Open the "System Configuration > Fading/Baseband Configuration".
Configure the following:
● Select "Mode > Advanced".
● Enable a 3x1x1 SISO scenario.
● Select "BB Sources > Separate".
● Select "Duplicate Streams > On".
● Confirm with "Apply".
2. Select "I/Q Stream Mapper".
Shifts and route the streams as follows:
● "Stream A > Frequency Offset = - 12 MHz"
● "Stream B > Frequency Offset = 6 MHz"
● "Stream C > Frequency Offset = - 6 MHz"
● "Stream D > Frequency Offset = 12 MHz"
● "RF A > Combination > Add"
● Stream A, B, C, D to RF A and Stream E to RF B
How to Generate Signals for GSM AM Suppression Tests
