A15.7.3 ACLR (ACIR in UL)

The ACLR calculation is similar to the unwanted calculation BUT note that in 3GPP it is the integration of the interfering power in the adjacent channel where the bandwidth equal to the interfering emission bandwidth while the unwanted uses the victim bandwidth (See illustration from 3GPP TR36.942 [12]).

Figure 457: Illustration of the ACLR for a 20 MHz E-UTRA UE aggressor ro 5 MHz E-UTRA UE victims (TR36.942 [12])

In UL ACIR^-1=ACLR_UE^-1+ACS_BS^-1, and the dominant part of ACIR is due to the UE adjacent channel leakage (ACLR) (i.e. ACS_BS is very large compare to ACLR_UE and ACIR ≈ ACLR_UE. When the victim system is CDMA or OFDMA only, the spectrum mask at the interferer (whether it is a non-CDMA/OFDMA or CDMA/OFDMA module) will automatically display the ACLR.

This feature allows you to have an idea of the ACLR value with respect to the spectrum mask that you enter. This will help you in comparing external results that have been generated based on an ACIR methodology.

Figure 458: ACLR interface – default value

When the ACLR display is activated, the Interefering link transmitter Emissions Mask dialog box is composed of 3 important parts

Part #1 corresponds the usual set of the spectrum mask.
Part #2 corresponds to setting the ACLR parameters:
Adjacent channel (MHz) (default value = 1 MHz);
Emission bandwidth (MHz) (default value = 1.25 MHz);
Update display button;
Part #3 corresponds to the display of the spectrum mask and the ACLR.

When you enter the mask, the ACLR is automaticaly calculated with the default ACLR setting parameter values.

Figure 459: ACLR interface – with a spectrum mask – Step 1

For this example, assuming that the first adjacent channel starts at 4.5 MHz and the interfering emission bandwidth of the system is 9 MHz, you have to set the parameters as shown in Figure 460. The green bars represents for information the various ACLR depending on each of the adjacent channels (see Figure 461 for a zoom of the display). On the right hand side the axis represent the normalized ACLR in dB.

Figure 460: ACLR interface – with a spectrum mask – Step 2

Figure 461: Zoom of the display

[A1]Section to be deleted, as this functionality is not present in SEAMCAT from at least version 4.1.0