Multi-TTI Scheduling via DCI Format Segmentation

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Solution Overview

Problem

Current wireless communication systems face inefficiencies in scheduling data transmissions over multiple transmission time intervals (TTIs), particularly in handling Downlink (DL) and Uplink (UL) control information and hybrid automatic repeat request (HARQ) processes, which affect data transport block scheduling and acknowledgement signaling.

Innovation Solution

The method involves transmitting Physical Downlink Shared Channels (PDSCHs) and Physical Uplink Shared Channels (PUSCHs) using Downlink Control Information (DCI) formats that include binary elements to schedule transmissions across multiple TTIs, employing asynchronous and synchronous hybrid automatic repeat request processes, and optimizing acknowledgement signaling through specific PUCCH resource allocation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If a single DCI format is used to schedule PDSCH transmissions in multiple TTIs, then control signaling overhead is reduced, but scheduling flexibility and adaptability to varying channel conditions deteriorate

Engineering Contradiction:

Improvecontrol signaling overheadVSAvoidscheduling flexibility

Core Design Contradiction:

Loss of substanceVSAdaptability or versatility

Solution Approach 1:

The invention segments the scheduling function by introducing multiple DCI formats (first DCI format for single-TTI scheduling, second DCI format for multi-TTI scheduling). This allows the system to choose appropriate scheduling granularity based on channel conditions and traffic requirements, resolving the contradiction between reducing control overhead and maintaining scheduling flexibility.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically selects between different DCI formats and scheduling modes based on current channel conditions, buffer status, and traffic patterns. This dynamic adaptation enables the system to optimize between control overhead reduction and scheduling flexibility in real-time, resolving the technical contradiction.

Inventive Principle:

Principle #15Dynamics

2Reliability

If asynchronous HARQ processes are used for single PDSCH scheduling, then handling of out-of-order arrivals is improved, but complexity of HARQ process management increases

Engineering Contradiction:

Improvehandling of out-of-order arrivalsVSAvoidHARQ process management complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The invention introduces an intermediary mechanism (the second DCI format with multi-TTI scheduling) that coordinates HARQ processes across multiple TTIs. This intermediary structure manages the complexity of asynchronous HARQ by providing a unified scheduling framework, reducing the burden on individual HARQ processes while maintaining reliable out-of-order handling.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If multiple DCI formats are transmitted to support flexible scheduling, then scheduling adaptability is improved, but control signaling overhead increases

Engineering Contradiction:

Improvescheduling adaptabilityVSAvoidcontrol signaling overhead

Core Design Contradiction:

Adaptability or versatilityVSLoss of substance

Solution Approach 1:

The second DCI format is designed with multi-functionality to handle various multi-TTI scheduling scenarios (different numbers of TTIs, different PDSCH configurations). This universal format reduces the need for numerous specialized DCI formats, thereby maintaining scheduling adaptability while controlling the increase in control signaling overhead.

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Reliability

If PUCCH resources are allocated for each PDSCH in multiple TTIs, then acknowledgement reliability is improved, but resource consumption increases

Engineering Contradiction:

Improveacknowledgement reliabilityVSAvoidPUCCH resource consumption

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The invention merges multiple PUCCH resources into a unified resource or resource set for transmitting acknowledgements related to multiple PDSCHs across different TTIs. This consolidation maintains acknowledgement reliability by ensuring dedicated resources while reducing overall PUCCH resource consumption compared to allocating separate resources for each PDSCH.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentEP2962408B1Scheduling over multiple transmission time intervals

Publication Date: 2019.11.20 SAMSUNG ELECTRONICS CO LTD

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AI summary

Methods and apparatus of a NodeB or a User Equipment (UE) in communication with each other are provided. The NodeB transmits and the UE receives Physical Downlink Data CHannels (PDSCHs) or the UE transmits and the NodeB receives Physical Uplink Data CHannels (PUSCHs) in respective Transmission Time Intervals (TTIs). The PDSCHs or the PUSCHs are scheduled by a Downlink Control Information (DCI) format transmitted in a Physical Downlink Control CHannel (PDCCH) in a TTI. A communication process enabling multi-TTI or cross-TTI scheduling of PDSCHs or PUSCHs is provided.