Question: What is the primary measure represented by Adjacent Channel Leakage power Ratio (ACLR) in the context of UTRA-UE transmission?
Option 1: Ratio of in-channel power to adjacent channel interference, quantifying leakage into neighboring frequencies.
Option 2: Comparison of transmit power between different types of UTRA-UE devices.
Option 3: Measurement of receiver sensitivity to adjacent channel signals.
Option 4: Evaluation of the UE's ability to filter out noise from its assigned channel.
Explanation: ACLR is a key metric in wireless communications, specifically measuring how much of a transmitter's power "leaks" into adjacent frequency channels. This ratio helps in understanding and mitigating interference between closely spaced channels. By comparing the in-channel power to the power in an adjacent channel, ACLR effectively quantifies this leakage, making **Option 1** the correct answer as it accurately describes the primary measure represented by ACLR.