PDSCH Processing With Downlink Preemption Indication Timing

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Solution Overview

Problem

In wireless communication systems, particularly in NR and LTE, there is a challenge in processing physical downlink shared channel (PDSCH) transmissions when they are preempted by another PDSCH, leading to insufficient time for user equipment (UE) to complete processing and provide feedback before the indicated timing.

Innovation Solution

The base station (BS) determines a sufficiently large feedback timing indicator (k1 value) to ensure that the downlink preemption indication (DLPI) can be incorporated into PDSCH decoding, allowing the UE to send hybrid automatic repeat request (HARQ) feedback within the indicated timing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the base station transmits downlink preemption indication (DLPI) to indicate preempted resources, then the decoding performance at the UE is improved, but the processing time for the UE becomes insufficient to complete PDSCH decoding and provide HARQ feedback before the indicated timing

Engineering Contradiction:
Improvedecoding performanceVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The base station determines a sufficiently large feedback timing indicator (k1 value) in advance, before the UE receives and processes the DLPI. This preliminary timing arrangement ensures that the UE has adequate time to incorporate the DLPI into its PDSCH decoding process and still provide HARQ feedback within the indicated timing, thus resolving the time insufficiency problem while maintaining improved decoding performance.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the feedback timing indicator (k1 value) is set to ensure timely HARQ feedback, then the communication reliability is improved, but the UE may not have sufficient time to incorporate DLPI into PDSCH decoding

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidprocessing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The base station adjusts the feedback timing indicator (k1 value) parameter to be sufficiently large, changing the timing parameter to balance two requirements: ensuring the UE has enough time to process DLPI and decode PDSCH, while still meeting the HARQ feedback timing requirements for communication reliability. This parameter optimization resolves the contradiction between reliability and processing time.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3776963B1Pdsch processing in presence of downlink preemption indication
Publication Date: 2025.02.12 QUALCOMM INC
  • EP3776963B1 patent drawingFigure 1
  • EP3776963B1 patent drawingFigure 2
  • EP3776963B1 patent drawingFigure 3

AI summary

Certain aspects of the present disclosure provide techniques for physical downlink shared channel (PDSCH) processing in presence of downlink preemption indication (DLPI). A method for wireless communication by a base station (BS) includes determining a feedback timing indicator associated with a PDSCH transmission to a user equipment (UE) in a first slot. The determination is based on a first number of slots from the first slot until transmission of a DLPI to the UE in a second slot and a second number slots for a minimum processing time associated with the UE. The method includes sending downlink control information (DCI) to the UE scheduling the PDSCH transmission to the UE in the first slot. The DCI includes the feedback timing indicator. The UE determines how to process the PDSCH based on the feedback timing indicator.