DMRS-Based PNT-RS Sequence Generation for 5G Phase Noise Tracking
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Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently managing phase noise in high-frequency 5G deployments, leading to increased overhead and reduced data rates due to the need for separate Phase Noise Tracking Reference Signals (PNT-RS) that interfere with Demodulation Reference Signals (DMRS), complicating synchronization procedures and resource utilization.
Innovation Solution
Generate Phase Noise Tracking Reference Signals (PNT-RS) sequences from Demodulation Reference Signals (DMRS) by copying DMRS symbols to resource elements assigned to PNT-RS, allowing for efficient phase noise tracking without blocking DMRS resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate PNT-RS are transmitted alongside DMRS for phase noise tracking, then phase noise compensation accuracy is improved, but resource overhead increases and DMRS availability is reduced
Solution Approach 1:
The patent combines PNT-RS and DMRS into a single transmitted signal structure where the PNT-RS is generated by copying DMRS symbols to specific resource elements. This merging allows phase noise tracking functionality to be integrated within the existing DMRS framework, eliminating the need for separate PNT-RS transmissions and thereby reducing resource overhead while maintaining tracking accuracy.
Solution Approach 2:
The DMRS structure is designed to serve multiple functions simultaneously: it provides both demodulation reference signal functionality and phase noise tracking reference signal functionality. By making the DMRS universal, the system eliminates the need for dedicated separate PNT-RS, reducing overhead while maintaining both demodulation and phase noise compensation capabilities.
2Measurement precision
If PNT-RS are transmitted in every OFDM symbol for continuous phase noise tracking, then frequency synchronization accuracy is improved, but receiver processing complexity increases
Solution Approach 1:
The patent performs preliminary action by generating the PNT-RS sequence in advance through copying DMRS symbols to predetermined resource elements. This pre-generation approach allows the receiver to have the phase noise tracking references ready without requiring complex real-time processing, as the reference structure is already established from the DMRS copies.
3Productivity
If DMRS are placed early in the subframe for early channel estimation, then demodulation performance is improved, but phase noise tracking capability is reduced
Solution Approach 1:
The patent resolves this contradiction by utilizing the frequency dimension. Multiple DMRS symbols are copied to different resource elements (different frequencies) to create multiple PNT-RS instances. This allows early channel estimation in the time domain while simultaneously providing phase noise tracking references across multiple frequency points, thus maintaining both early processing capability and accurate phase noise tracking.
Data Source
AI summary
A user equipment (910) is provided for use in a cellular network. The user equipment includes a transceiver (1010), a processor (1020), and a memory (1030). The user equipment (910) is configured to determine, for a data transmission, a mapping form a demodulation reference signal (DMRS) to a PNT-RS. A DMRS resulting signal is generated from a subset of DMRS for a first resource element in a subcarrier. The DMRS resulting signal is copied from the first resource element to a second resource element assigned to the PNT-RS in the subcarrier. The data transmission is transmitted using the DMRS resulting signal and the PNT-RS.