Question: For a UTRA FDD User Equipment (UE) supporting High-Speed Downlink Packet Access (HSDPA), what is the primary basis for calculating the Adjacent Channel Leakage Ratio (ACLR) as per Release 5 and later releases?
Option 1: The ratio of the peak power to the mean noise floor in the assigned channel.
Option 2: The ratio of the filtered mean power centred on the assigned channel frequency to the filtered mean power centred on an adjacent channel frequency.
Option 3: Comparison of signal strengths between two adjacent base stations.
Option 4: Measurement of throughput in HSDPA-enabled UEs under varying network loads.
Explanation: ACLR is a critical metric for assessing the spectral containment of wireless transmissions. In the context of UTRA FDD UEs supporting HSDPA, ACLR measures the ratio of in-channel power to adjacent channel power, ensuring transmissions do not unduly interfere with neighboring channels, impacting spectrum use and network performance.