PDSCH Time Domain Resource Allocation Relative Reference

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Solution Overview

Problem

Existing Time Domain Resource Allocation (TDRA) for multi-TRP in New Radio (NR) does not consider the reference for PDSCH as a slot boundary, leading to undefined UE behavior, and does not account for the new reference of PDSCH SLIV for DL-SPS PDSCH or back-to-back repetition of PDSCH in single-TRP scenarios.

Innovation Solution

A method for determining the start symbol of PDSCH transmission occasions using a relative reference symbol, enabling/disabling the use of S0 as the reference point, and adjusting the offset value K to ensure PDSCH repetitions do not cross the slot boundary, with error handling mechanisms for crossing symbols.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If PDSCH repetitions are scheduled using existing TDRA without considering slot boundary references, then scheduling flexibility is improved, but UE behavior becomes undefined and reliability deteriorates

Engineering Contradiction:

Improvescheduling flexibilityVSAvoidUE behavior definition

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent changes the reference parameter from absolute slot boundaries to relative reference symbols (S0) for TDRA. This allows flexible scheduling while maintaining well-defined UE behavior through the relative offset K parameter that ensures repetitions stay within slot boundaries.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces an intermediary mechanism (the relative reference symbol S0 and offset K) between the scheduling decision and the actual PDSCH transmission. This intermediary ensures that even with flexible scheduling, the UE behavior remains well-defined by using the relative offset to calculate actual transmission positions.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If PDSCH repetitions cross slot boundaries, then resource utilization is improved, but error handling becomes complex and reliability deteriorates

Engineering Contradiction:

Improveresource utilizationVSAvoiderror handling complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent applies preliminary anti-action by using the relative offset K to pre-calculate and prevent PDSCH repetitions from crossing slot boundaries. The offset is configured to ensure the last symbol of one repetition and the first symbol of the next repetition remain within valid slot boundaries, avoiding boundary crossing errors before they occur.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The patent segments the PDSCH transmission into multiple repetitions with defined boundaries using the relative reference symbol approach. Each repetition is separated by the offset K, creating clear segments that prevent boundary crossing and simplify error handling for each segment.

Inventive Principle:

Principle #1Segmentation

3Measurement precision

If relative reference symbol S0 is used for TDRA, then scheduling precision is improved, but compatibility with existing NR TDRA deteriorates

Engineering Contradiction:

Improvestart symbol indication precisionVSAvoidcompatibility with existing TDRA

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent introduces dynamic configurability through the parameter K (offset value) that can be adjusted based on the specific scheduling scenario. This dynamic approach allows the system to adapt between relative reference mode (for precision) and maintains compatibility with existing NR TDRA through configurable operation modes.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent creates a universal TDRA mechanism that can function in multiple modes: traditional absolute slot boundary reference mode and new relative reference symbol mode. The relative offset K parameter serves multiple purposes: defining the reference point, calculating offsets between repetitions, and ensuring boundary compliance, thereby maintaining compatibility while enabling enhanced functionality.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS20250212217A1Systems and methods of signaling time domain resource allocation for pdsch transmission

Publication Date: 2025.06.26 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

A method performed by a wireless device for determining a start symbol of a plurality of PDSCH transmission occasions using a relative reference symbol includes: receiving an indication that includes indications: that enable/disable the use of the relative reference symbol; the offset between the last symbol of a first PDSCH and the first symbol of a second PDSCH; that there are multiple PDSCH transmission occasions; and that a symbol of the first transmission occasion and length corresponding to all transmission occasions; and determining the symbol at which each of the plurality of PDSCH transmission occasions end which will be used to determine the start symbol of the next PDSCH transmission occasion. In this way, the wireless device behavior is defined on how many PDSCH repetitions the wireless device can receive when the use of the new relative reference for the starting symbol of the first PDSCH repetition is enabled.