Adjacent Channel Leakage Ratio (ACLR) Measurement Description

Adjacent Channel Leakage Ratio (ACLR) Measurement Description

Last updated: January 16, 2009

How is an Adjacent Channel Leakage Ratio Measurement Made?

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 for individual offsets can be turned off to increase measurement speed when these measurements are not needed.

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."

Adjacent Channel Leakage Ratio Measurement Parameters

Adjacent Channel Leakage Ratio Input Signal Requirements

Adjacent Channel Leakage Ratio Measurement Calibration

You must calibrate this measurement using the Calibrate Measurements procedure (see Calibrating the Test Set ).

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