Question: In a TDD (Time Division Duplexing) system, as per 3GPP specifications, what is the primary reference for measuring Out of Channel Emissions for a User Equipment (UE)'s spectrum emission mask?
Option 1: The unfiltered peak power of the UE's transmitted signal
Option 2: The filtered mean power of the UE carrier
Option 3: The average noise floor of the receiving base station
Option 4: The maximum allowable transmit power for the UE's frequency band
Explanation: This question requires understanding of radio transmission and reception specifications in TDD systems, particularly how out of channel emissions are measured. The correct answer, "The filtered mean power of the UE carrier", is based on the principle that out of channel emissions need a reference point for measurement, which in this context is the filtered mean power of the UE's own carrier signal. This ensures that the measurement accounts for the UE's transmission characteristics while assessing potential interference. The other options are incorrect because they either refer to unfiltered or peak values (Option 1), external references unrelated to the UE's transmission (Option 3), or general power limits not specific to emission masking (Option 4).