5G • 5G-Advanced (Rel-18)
Dynamic Port Selection
Instantaneous Antenna Port Switching for Uplink Transmission
Allows a user device to dynamically switch active uplink transmit antenna ports on a slot-by-slot basis to bypass blocked antennas.
Technical Explanation
When a smartphone user holds a device, fingers often block one or two antennas completely. In Rel-18 Dynamic Port Selection, the gNodeB detects fading on blocked ports using Sounding Reference Signals (SRS) and commands the UE via DCI to route transmit power to unblocked antenna ports in real time, avoiding dropped packets without renegotiating full MIMO connections.
Key Functions
- Dynamically routes uplink transmit power away from blocked or detuned antennas
- Executes antenna port switching on a per-slot basis via fast physical layer DCI commands
- Maintains maximum Effective Isotropic Radiated Power (EIRP) despite user hand grip
- Avoids latency-intensive RRC antenna reconfiguration procedures
Specifications
3GPP TS 38.214 (Rel-18)
Interfaces
Uu (DCI Format 0_1/0_2)
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