Question: In a 5G NR (New Radio) network, for a User Equipment (UE) transmitting a Phase Tracking Reference Signal (PT-RS), what determines the number of antenna ports used for PT-RS transmission in frequency range 2?
Option 1: The number of antenna ports is determined by the UE's PT-RS transmission power.
Option 2: The number of antenna ports is the same as the number of PUCCH (Physical Uplink Control Channel) antenna ports.
Option 3: The number of antenna ports is dynamically signaled by the gNB (Next Generation Node Base Station) for each PT-RS transmission.
Option 4: The number of antenna ports is the same as the number of PSSCH DM-RS (Physical Shared Sidelink Channel Demodulation Reference Signal) antenna ports.
Explanation: According to the procedure for PT-RS transmission in frequency range 2, the number of antenna ports used for transmitting PT-RS is directly tied to the configuration of PSSCH DM-RS antenna ports. This ensures a fixed association between PT-RS and PSSCH DM-RS antenna ports, simplifying spatial processing for sidelink communications, maintaining coherent demodulation, and efficient resource use in sidelink transmissions.