Half-Duplex FDD Scheduling via Fixed Periodic Subframe Patterns

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Solution Overview

Problem

Conventional dynamic scheduling for half-duplex (HD) communication systems in LTE networks is complex and resource-intensive, requiring logic to determine subframe types and coordinating between uplink (UL) and downlink (DL) entities, leading to high processing and memory costs due to numerous possible combinations of subframes.

Innovation Solution

Implementing a fixed periodic subframe pattern that defines UL, DL, and guard subframes, allowing the scheduler to easily identify subframe types and optimize scheduling for HD-FDD devices, reducing complexity and resource requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional dynamic scheduling is used for HD communication systems, then scheduling flexibility is improved, but device complexity and processing costs increase

Engineering Contradiction:

Improvescheduling flexibilityVSAvoidscheduler complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the scheduling problem by separating the determination of subframe types from the scheduling decisions. The fixed periodic pattern divides time into predetermined DL, UL, and guard subframes, allowing the scheduler to operate independently within each subframe type without complex cross-subframe coordination logic.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements a fixed periodic subframe pattern where DL, UL, and guard subframes repeat in a predetermined sequence. This periodic structure eliminates the need for dynamic determination of subframe types and reduces scheduling complexity while maintaining systematic resource allocation.

Inventive Principle:

Principle #19Periodic action

2Productivity

If conventional dynamic scheduling with coordination between UL and DL entities is implemented, then resource allocation efficiency is improved, but processing and memory costs increase

Engineering Contradiction:

Improveresource allocation efficiencyVSAvoidprocessing and memory costs

Core Design Contradiction:

ProductivityVSPower

Solution Approach 1:

The patent applies preliminary action by pre-defining the subframe pattern before scheduling operations begin. The fixed periodic pattern establishes DL, UL, and guard subframe assignments in advance, eliminating the need for complex real-time coordination and reducing processing and memory requirements during actual scheduling execution.

Inventive Principle:

Principle #10Preliminary action

3Device complexity

If a fixed periodic subframe pattern is used, then device complexity is reduced, but scheduling flexibility decreases

Engineering Contradiction:

Improvescheduler complexityVSAvoidscheduling flexibility

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The fixed periodic subframe pattern serves multiple functions simultaneously: it defines subframe types for HD operation, provides systematic resource allocation, and enables efficient HARQ timing management. This universal approach handles various scheduling requirements through a single structured framework, maintaining adequate flexibility despite the fixed pattern.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentEP3338498B1Scheduling for half-duplex frequency division duplexing user equipment

Publication Date: 2020.02.12 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

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AI summary

A network node identifies a fixed periodic pattern to be used for scheduling a half- duplex (HD) user equipment (UE), the fixed periodic pattern defining a sequence of at least one downlink (DL) subframe, then at least one guard period, and then at least one uplink (UL) subframe. The network node then performs DL assignments for the network node according to the fixed periodic pattern and transmits UL grants to the UE according to the fixed periodic pattern.