PUSCH Transform Precoder Signaling for Clear DCI Interpretation

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Solution Overview

Problem

Existing mobile communication systems face challenges in interpreting transform precoder indicator fields in DCI formats due to differing bit widths for dynamic grant and configured-grant PUSCH, leading to ambiguity and unnecessary waveform switching, which affects latency and resource efficiency.

Innovation Solution

A method to interpret the transform precoder indicator field based on uplink scheduling methods, using a 1-bit field for dynamic grant and configured grant PUSCH, with specific rules for CRC scrambled by different RNTIs, ensuring clear interpretation and limiting unnecessary waveform switching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a transform precoder indicator field is present in DCI format for both dynamic grant and configured-grant PUSCH, then waveform switching capability is enabled, but interpretation ambiguity arises due to different scheduling methods

Engineering Contradiction:
Improvewaveform switching capabilityVSAvoidinterpretation ambiguity
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent applies different interpretation rules to the transform precoder indicator field based on the scheduling method. For dynamic grant PUSCH, the field indicates transform precoding enablement directly. For configured-grant PUSCH, the field interpretation depends on the NDI value: when NDI=0 it is reserved, when NDI=1 it indicates transform precoding enablement. This local differentiation resolves the ambiguity while maintaining waveform switching capability.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If transform precoding is dynamically switched for configured-grant PUSCH, then channel adaptation is improved, but latency increases due to unnecessary waveform switching

Engineering Contradiction:
Improvechannel adaptationVSAvoidlatency
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent applies transform precoding dynamically only when necessary (when NDI=1 indicating new data transmission), while reserving the field when NDI=0 (indicating retransmission or activation). This partial application of waveform switching avoids unnecessary processing and latency while maintaining channel adaptation benefits when needed.

Inventive Principle:
Principle #16Partial or excessive action

3Device complexity

If DCI size alignment is applied to ensure equal bit width for different RNTI-based DCI formats, then device complexity is reduced, but field interpretation becomes ambiguous

Engineering Contradiction:
ImproveDCI format structureVSAvoidfield interpretation clarity
Core Design Contradiction:
Device complexityVSLoss of information

Solution Approach 1:

The patent maintains DCI size alignment for structural simplicity but introduces local interpretation rules based on the RNTI type and NDI value. The transform precoder indicator field is interpreted differently for C-RNTI (dynamic grant) versus CS-RNTI (configured-grant), allowing the same field structure to serve multiple scheduling methods without ambiguity.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4694491A1Method and apparatus for transmitting and receiving uplink channel in wireless communication system
Publication Date: 2026.02.11 LG ELECTRONICS INC
  • EP4694491A1 patent drawingFigure 1~2
  • EP4694491A1 patent drawingFigure 3~4
  • EP4694491A1 patent drawing

AI summary

A method according to an embodiment of the present disclosure includes receiving configuration information related to a Physical Uplink Shared CHannel (PUSCH), receiving Downlink Control Information (DCI) including a New Data Indicator (NDI) field, and transmitting the PUSCH based on the DCI. Based on a parameter related to a presence of a transform precoder indicator field in the DCI being configured based on the configuration information, the transform precoder indicator field is based on 1 bit. A value of the 1 bit indicates that a transform precoder is enabled or disabled. Based on i) a Cyclic Redundancy Check (CRC) related to the DCI being scrambled by a Configured Scheduling (CS)-Radio Network Temporary Identifier (RNTI) and ii) a value of the NDI field being '0': the 1 bit is reserved.