Terminal Phase Tracking for Doppler Estimation Without Dense Uplink Pilots

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Solution Overview

Problem

In new radio (NR) systems, the network device struggles to accurately estimate Doppler shift due to limitations in uplink pilot density, leading to inefficient information transmission.

Innovation Solution

A method where a terminal device determines phase information of the transmission path using a tracking reference signal and transmits it to the network device, allowing the network device to determine channel information without the need for data conversion and quantified feedback, thereby reducing overhead and improving transmission efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If uplink pilot density is increased to improve Doppler shift estimation accuracy, then measurement precision improves, but device complexity and resource overhead increase

Engineering Contradiction:

ImproveDoppler shift estimation accuracyVSAvoiduplink pilot density

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces phase information as an intermediary parameter between the tracking reference signal and Doppler shift estimation. Instead of directly estimating Doppler shift from limited uplink pilots, the terminal first extracts phase information from the tracking reference signal, then uses this phase information to derive accurate Doppler shift values, effectively decoupling the estimation accuracy from uplink pilot density

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the traditional mechanical approach of increasing uplink pilot density with a signal processing approach. By substituting the physical layer solution (more pilots) with a layer 2/3 solution (phase information extraction and processing), the system achieves the same estimation accuracy without increasing resource overhead

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Loss of information

If data conversion and quantified feedback are implemented for Doppler shift reporting, then information accuracy improves, but feedback indication overhead increases

Engineering Contradiction:

ImproveDoppler shift information accuracyVSAvoidfeedback indication overhead

Core Design Contradiction:

Loss of informationVSQuantity of substance

Solution Approach 1:

The patent extracts only the essential phase information from the complete Doppler shift data, separating the critical component needed for channel prediction from the redundant quantified feedback. This extraction approach transmits only the necessary information for maintaining channel estimation accuracy while eliminating unnecessary data overhead

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of converting Doppler shift to quantified feedback and then transmitting, the patent inverts the process by directly transmitting raw phase information that can be converted back to Doppler shift at the network side, avoiding the overhead of quantization and conversion tables

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS20250301355A1Method and apparatus for transmitting information, device, and storage medium

Publication Date: 2025.09.25 BEIJING XIAOMI MOBILE SOFTWARE CO LTD

AI summary

A method for transmitting information includes: receiving a tracking reference signal, determining phase information of a transmission path according to the tracking reference signal, and transmitting the phase information to a network device.