Question: In a Missed ACK test scenario, where the Serving Station (SS) responds with 100% ACK, what does the User Equipment (UE) interpret as NACK by higher layer, causing retransmission?
Option 1: New data transmission on E-DPCCH and E-DPDCH
Option 2: Retransmission indicated on E-DPCCH
Option 3: Receipt of DTX on E-HICH
Option 4: Successful decoding of QPSK H-Set 1
Explanation: According to the measurement principle for the missed ACK test, when the UE indicates a retransmission on the E-DPCCH, it signifies that the UE received the previous ACK as NACK or DTX, prompting the retransmission. This scenario highlights how higher layers interpret retransmissions in this context, emphasizing accurate feedback for reliable wireless data transfer.