5G • 5G-Advanced (Rel-18)
Rel-18 PTRS Enhancements
Phase Tracking Reference Signal Optimization for High-Order Modulation
Optimized Phase Tracking Reference Signals that track oscillator phase noise in upper mid-band (FR3) and mmWave, enabling 1024-QAM modulation.
Technical Explanation
Phase noise generated by local oscillators severely degrades signal constellations in high-frequency bands, particularly when utilizing dense modulation schemes like 1024-QAM. Rel-18 enhances Phase Tracking Reference Signals (PTRS) with adaptive density patterns and multi-port tracking, neutralizing phase jitter and enabling ultra-high-order modulations in 5G-Advanced.
Key Functions
- Tracks and cancels local oscillator phase noise and carrier frequency offset in real time
- Enables clean demodulation of dense 256-QAM and 1024-QAM constellations in FR2/FR3
- Optimizes pilot tone time-frequency density to minimize reference signal overhead
- Supports multi-port PTRS for high-order spatial multiplexing and dual-polarized arrays
Specifications
3GPP TS 38.211, TS 38.214 (Rel-18)
Interfaces
Uu (PTRS)
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