Double-Sided RTT Measurement With TEG Delay Compensation

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Solution Overview

Problem

Existing wireless communication systems, particularly 5G NR, face challenges in accurately determining round trip time (RTT) measurements due to timing errors associated with the transmission and reception of positioning reference signals (PRS) and sounding reference signals (SRS), which affect positioning accuracy.

Innovation Solution

Incorporating timing error group (TEG) delays into RTT measurements by determining and accounting for various TEG delays associated with the transmission and reception of PRS/SRS, enabling more accurate double RTT calculations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If timing error group (TEG) delays are incorporated into RTT measurements, then measurement precision is improved, but device complexity increases

Engineering Contradiction:

ImproveRTT measurement accuracyVSAvoidtiming delay compensation complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The base station pre-calculates and stores multiple TEG delay values corresponding to different transmission and reception timing scenarios before RTT measurement. When performing RTT measurement, the UE and base station simply select and apply the appropriate pre-computed TEG delay value based on their timing relationship, avoiding complex real-time calculations and reducing processing complexity while maintaining high measurement precision

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The timing error compensation is segmented into multiple discrete TEG delay values, each representing a specific timing error scenario. Instead of attempting to compensate for all possible timing errors continuously, the system divides the timing error space into discrete groups and provides compensation for each group, simplifying the overall compensation mechanism while covering the full range of timing variations

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If multiple TEG delay values are stored and transmitted, then measurement precision is improved, but loss of information increases

Engineering Contradiction:

Improvepositioning accuracyVSAvoidsignaling overhead

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

Instead of transmitting all possible TEG delay values to ensure complete information, the system transmits only the necessary subset of TEG delay values that are relevant for the current RTT measurement scenario. This partial transmission approach reduces signaling overhead while providing sufficient information for accurate measurement, as not all TEG delay combinations are needed in every measurement instance

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS12550113B2Configuration and measurement enhancements for double-sided round trip time

Publication Date: 2026.02.10 QUALCOMM INC

AI summary

A UE receives, from a BS, information indicating a first TEG delay at the BS for a transmission of a first PRS, a second TEG delay at the BS for a reception of an SRS from the UE, a third TEG delay at the BS for a transmission of a second PRS, a fourth TEG delay at the BS for a transmission of the first PRS and a reception of the SRS from the UE, or a fifth TEG delay at the BS for a reception of the SRS from the UE and a transmission of the second PRS, or any combination thereof. The UE determines a double RTT based on a first PRS timing associated with a reception of the first PRS, an SRS timing associated with a transmission of the SRS, a second PRS timing associated with a reception of the second PRS, and the received information.