5G • RAN
PT-RS
Phase Tracking Reference Signal
Low-density reference signal in downlink and uplink designed to track and cancel high-frequency phase noise in mmWave (FR2).
Technical Explanation
At high millimeter-wave carrier frequencies (FR2), local oscillator phase noise causes significant Common Phase Error (CPE) and Inter-Carrier Interference (ICI). PT-RS is sparsely distributed in frequency (1 subcarrier every 2 or 4 PRBs) and dense in time (every 1, 2, or 4 symbols) to track and cancel rapid phase variations.
Key Functions
- Tracks and corrects Common Phase Error (CPE) caused by oscillator phase noise
- Essential for high-order modulation (64QAM, 256QAM) in mmWave (FR2)
- Dynamically configured based on scheduled bandwidth and MCS
Specifications
3GPP TS 38.211, TS 38.214
Interfaces
Uu
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