Question: What is the primary reason for restricting a signal under test to use exactly one scrambling code in Base Station (BS) conformance testing, specifically in relation to PCDE (Primary Common Control Physical Channel Dedicated Emissions)?
Option 1: To ensure accurate investigation of unused channelization codes and their associated scrambling codes.
Option 2: To simplify the testing process by reducing the number of variables.
Option 3: To enhance security by limiting the scrambling code options.
Option 4: To improve signal strength by focusing on a single scrambling code.
Explanation: The correct answer is Option 1 because, according to the provided context, restricting the signal under test to use exactly one scrambling code is necessary for accurately investigating unused channelization codes through PCDE. This is crucial for understanding how these codes are managed in relation to their assigned scrambling codes, ensuring proper configuration and operation within the base station's transmission setup.