Occupied Bandwidth Measurement Concepts - Keysight X Series Measurement Manual

Concepts
MSR Measurement Concepts

Occupied Bandwidth Measurement Concepts

Purpose
Occupied bandwidth measurements express the percentage of the transmitted
power within a specified bandwidth. This percentage is typically 99%.
The spectrum shape of a signal can give useful qualitative insight into
transmitter operation. Any distortion to the spectrum shape can indicate
problems in transmitter performance.
Occupied bandwidth in MSR is designed to measure occupied bandwidth of
multiple carriers of different formats, although it is required by the 3GPP MSR
standard and the other single format standards that it is measured with a
single carrier with specified span.
Measurement Method
The instrument uses sweep mode to capture the data and the total power
within the measurement frequency span is integrated for its 100% of power.
The frequencies of 0.5% of the total power are then calculated to get 99.0%
bandwidth.
Span auto detection is supported in MSR mode OBW. When in auto detection
mode, the frequency range determined by Measure Carrier on of carrier #1 to
Carriers is roughly examined to determine the span of OBW. FOffset,OBW is
defined for each format as below.
-
-
-
-
FOffset,OBW of LTE (E-UTRA) and W-CDMA (UTRA FDD) are determined from
occupied bandwidth test methods defined in the 3GPP standard. For
GSM/EDGE it is based on the default channel spacing. Center frequencies of
active carriers and corresponding FOffset,OBW determine the span. Since
FOffset,OBW value is based on the standard, the span is set to the one required
by the standard for OBW test of corresponding format when only one carrier is
detected by the auto detection.
Keysight N9083A & W9083A Measurement Guide
FOffset,OBW for LTE 1.4, 3, 5 MHz:
FOffset,OBW for LTE other BW:
FOffset,OBW for W-CDMA:
FOffset,OBW for GSM/EDGE:
10 MHz
BWchanel MHz
5MHz
300 kHz
55