Question: In a Multi-Standard Radio (MSR) Base Station (BS) Electromagnetic Compatibility (EMC) test, as per 3GPP specifications, what is the required amplitude modulation depth for the 1 kHz sinusoidal audio signal used in the test level of 3 V/m?
Option 1: 50% amplitude modulation depth
Option 2: 80% amplitude modulation depth
Option 3: 90% amplitude modulation depth
Option 4: 100% amplitude modulation depth
Explanation: The correct answer is Option 2 because, according to the specified test methodology for MSR Base Station EMC (aligned with IEC standards), the test level of 3 V/m must be amplitude modulated to a depth of 80% by a sinusoidal audio signal of 1 kHz. This specific modulation depth is crucial for accurately assessing the electromagnetic compatibility of the base station across the defined frequency range, ensuring reliable operation without undue interference.