PT-RS Configuration for Phase Noise Tracking in 5G
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems, particularly in 5G networks, face challenges in efficiently configuring Phase Tracking Reference Signals (PT-RS) for adaptive Hybrid Automatic Repeat Request (HARQ) processes, especially in managing PT-RS time and frequency domain density and resource mapping.
Innovation Solution
The proposed solution involves dynamic configuration of PT-RS, including determining its time and frequency domain density and resource mapping, based on techniques such as the number of front-loaded DM-RS symbols, additional DM-RS symbols, and the use of Orthogonal Cover Code (OCC) for DM-RS and CSI-RS. This configuration is optimized for both CP-OFDM and DFT-s-OFDM waveforms to enhance phase noise mitigation and improve communication reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If PT-RS density is increased in time and frequency domains, then phase noise tracking precision is improved, but signaling overhead and resource consumption increase
Solution Approach 1:
The patent implements dynamic PT-RS density configuration where the density of PT-RS in time and frequency domains is adjusted based on channel conditions, phase noise characteristics, and service requirements. This allows the system to increase PT-RS density when phase noise is severe (improving tracking precision) while reducing density when conditions are favorable (reducing resource consumption), thereby resolving the contradiction between measurement precision and quantity of substance.
Solution Approach 2:
The patent changes key parameters including PT-RS time domain density, frequency domain density, and resource element mapping patterns to optimize phase noise tracking. By dynamically adjusting these parameters based on operational conditions, the system achieves high tracking precision when needed while minimizing overall resource consumption, directly addressing the contradiction between measurement precision and quantity of substance.
2Reliability
If PT-RS configuration is optimized for high-frequency bands, then phase noise mitigation is improved, but system complexity increases
Solution Approach 1:
The patent applies different PT-RS configuration parameters for different frequency bands, specifically optimizing for high-frequency bands where phase noise is more severe. This includes adjusting time and frequency density, resource element mapping, and OCC patterns specifically for mmWave and other high-frequency operations. By applying localized optimizations only where needed (high-frequency bands) rather than uniformly across all bands, the system achieves improved phase noise mitigation while avoiding unnecessary complexity in lower frequency operations.
3Reliability
If adaptive HARQ process uses dynamic PT-RS configuration, then communication reliability is improved, but control signaling overhead increases
Solution Approach 1:
The patent configures PT-RS parameters in advance through higher-layer signaling (RRC configuration) including time domain density, frequency domain density, and resource element patterns. This preliminary configuration allows the UE to efficiently interpret downlink control information (DCI) during adaptive HARQ operations without requiring extensive real-time signaling. The pre-configured parameters reduce the amount of control signaling needed during dynamic HARQ processes, thereby improving communication reliability while minimizing control signaling overhead.
Data Source
AI summary
A user equipment (UE) can include processing circuitry configured to decode downlink control information (DCI) from a base station, the DCI including a modulation coding scheme (MCS) index and physical uplink shared channel (PUSCH) allocation. A demodulation reference signal (DMRS) is encoded for transmission to the base station within a plurality of DMRS symbols based on the PUSCH allocation. A phase tracking reference signal (PT-RS) time domain density is determined based on the MCS index and a number count of the DM-RS symbols for the DM-RS transmission. The PTRS is encoded for transmission using a plurality of PT-RS symbols based on the determined time domain density. The plurality of symbols includes one or both of front-loaded DM-RS symbols and additional DM-RS symbols.