Uplink Repetition Timing Around SRS Subframes for Phase Continuity

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Solution Overview

Problem

In MTC terminals, the phase discontinuity in repetition transmissions due to SRS transmission candidate subframes disrupts the cross-subframe channel estimation and symbol level combining, leading to reduced channel estimation accuracy.

Innovation Solution

The base station and terminal adjust the timing of repetition signal transmission to avoid SRS transmission candidate subframes, ensuring phase continuity by setting X subframes that do not overlap with SRS candidate subframes, enabling cross-subframe channel estimation and symbol level combining.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If repetition transmission is performed in SRS transmission candidate subframes, then resource utilization is improved, but phase discontinuity occurs disrupting channel estimation

Engineering Contradiction:

Improveresource utilizationVSAvoidchannel estimation accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent extracts and removes the problematic SRS transmission candidate subframes from the repetition transmission schedule. By identifying subframes configured for SRS transmission (where data transmission is punctured) and excluding them from repetition transmission, the patent eliminates the source of phase discontinuity while preserving channel estimation accuracy.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent performs preliminary configuration of repetition transmission timing to avoid SRS candidate subframes. By pre-determining the repetition transmission subframes based on SRS configuration information received from the base station, the patent prevents phase discontinuity before it occurs, ensuring continuous phase across all repetition transmissions.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If data transmission is performed in SRS resource candidate symbols, then transmission efficiency is improved, but collision with SRS signals occurs

Engineering Contradiction:

Improvetransmission efficiencyVSAvoidsignal collision

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent converts the potential harm of resource collision into a benefit by using the SRS configuration information to optimize repetition transmission scheduling. Instead of treating SRS candidate subframes as wasted resources, the patent systematically excludes them from repetition transmission, ensuring phase continuity and enabling effective channel estimation across remaining subframes.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Measurement precision

If cross-subframe channel estimation is performed, then channel estimation accuracy is improved, but phase discontinuity from SRS subframes disrupts the estimation

Engineering Contradiction:

Improvechannel estimation accuracyVSAvoidphase continuity

Core Design Contradiction:

Measurement precisionVSStability of the object's composition

Solution Approach 1:

The patent segments the repetition transmission into multiple subframes while systematically excluding SRS candidate subframes. By dividing the transmission timeline and removing problematic segments (SRS subframes), the patent ensures that each segment maintains phase continuity, enabling successful cross-subframe channel estimation.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentEP3941138B1Terminal and transmission method

Publication Date: 2026.03.04 PANASONIC INTELLECTUAL PROPERTY CORP OF AMERICA

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AI summary

A repetition unit generates repetition signals by repeating uplink signals over a plurality of subframes; control unit sets a timing for transmitting the repetition signals, based on information indicating a transmission candidate subframe for a sounding reference signal (SRS) used for measuring an uplink reception quality; and a transmitting unit transmits the repetition signals at the set timing.