Rohde & Schwarz FSW13, User Manual

Page: 184 / 1150

Measurements
R&S
®
FSW
184 User Manual 1173.9411.02 ─ 19
Standard Remote parameter
APCO-25 P2 PAPCo25
User Standard USER
Customized Standard <string>
For the R&S FSW, the channel spacing is defined as the distance between the center
frequency of the adjacent channel and the center frequency of the transmission chan-
nel. The definition of the adjacent-channel spacing in standards IS95C and CDMA
2000 is different. These standards define the adjacent-channel spacing from the center
of the transmission channel to the closest border of the adjacent channel. This defini-
tion is also used by the R&S
FSW for the standards marked with an asterisk *) .
5.4 Carrier-to-Noise Measurements
The R&S FSW can easily determine the carrier-to-noise ratio, also normalized to a 1
Hz bandwidth.
● About the Measurement ........................................................................................184
● Carrier-to-Noise Results ........................................................................................185
● Carrier-to-Noise Configuration .............................................................................. 186
● How to Determine the Carrier-to-Noise Ratio ....................................................... 187
5.4.1 About the Measurement
The largest signal in the frequency span is the carrier. It is searched when the C/N or
C/NO function is activated and is marked using a fixed reference marker ("FXD").
To determine the noise power, a channel with a defined bandwidth at the defined cen-
ter frequency is analyzed. The power within this channel is integrated to obtain the
noise power level. (If the carrier is within this channel, an extra step is required to
determine the correct noise power level, see below.)
The noise power of the channel is subtracted from the maximum carrier signal level,
and in the case of a C/N
O
measurement, it is referred to a 1 Hz bandwidth.
For this measurement, the RMS detector is activated.
The carrier-to-noise measurements are only available in the frequency domain (span
>0).
Measurement process
Depending on whether the carrier is inside or outside the analyzed channel, the mea-
surement process for the carrier-to-noise ratio varies:
Carrier-to-Noise Measurements