Adjacent channel leakage ratio (ACLR) measures the relative power at ± 5 MHz and ± 10 MHz offsets from the uplink channel. Power is measured through a Root-Raised Cosine (RRC) filter with a rolloff of a=0.22, and a bandwidth equal to the chip rate (3.84 MHz). The ± 5 MHz measurements are referred to as the upper and lower first adjacent channels; the ± 10 MHz measurements are referred to as the upper and lower second adjacent channels. This measurement is defined in 3GPP TS 34.121, sections 5.10 and 5.10A, Adjacent Channel Power Leakage Ratio (ACLR).
Measurements can be displayed in either numeric or graphical form. When the graphical display is used (shown below), limits can be set for each offset to form a "limit line." When a limit is exceeded, the status changes from "Pass" to "Fail."
You may set
to the following: (for more information on these trigger types, see
Trigger Source Description
Auto: if the UE is synchronized to the test set, it uses protocol triggering; otherwise, it uses immediate triggering.
is set to
, you can specify on which uplink subframe the measurement triggers using the
HS-DPCCH Trigger Subframe Alignment
can only be set to HS-DPCCH when
12.2k RMC + HSDPA
12.2k RMC + HSPA
Protocol: Derived from the 10 ms downlink DPCH frame clock.
is set to
, you can specify on which uplink subframe the measurement triggers. You can then use the
setting to move the measurement interval (666.7 us = 1 timeslot) relative to that subframe boundary.
You must calibrate this measurement using the
Calibrating the Test Set