Question: For a UTRA FDD User Equipment (UE) supporting High-Speed Downlink Packet Access (HSDPA) and Enhanced Dedicated Channel (E-DCH), what primarily determines the receive characteristics of the E-DCH Absolute Grant Channel (E-AGCH) in a multi-path fading environment?
Option 1: Signal-to-Noise Ratio (SNR) of the downlink channel
Option 2: The transmission power of the Node B
Option 3: Missed detection probability
Option 4: The number of receive antennas at the UE
Explanation: In a multi-path fading environment, the reliability of receiving control channels like the E-AGCH is crucial for maintaining the integrity of the communication link. The missed detection probability directly influences how effectively the UE can detect and decode grants on the E-AGCH, thereby impacting the overall performance of E-DCH in such environments. This makes it the primary determinant of receive characteristics for E-AGCH under these conditions.