TDD Subframe Configuration for LTE Throughput and Adaptation

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Solution Overview

Problem

Current UL-DL subframe configurations in TDD frame structures for LTE systems do not provide optimal throughput, especially for heavy traffic scenarios, and can prevent dynamic adaptation when UEs operate standalone, leading to inadequate PRACH opportunities.

Innovation Solution

Implementing restricted subframe configurations based on the position of radio frames within a sequence or the type of information being transmitted, ensuring at least one subframe is reserved for downlink communication to allow UE to monitor group common DCI and maintain PRACH opportunities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If candidate subframe configurations are introduced to increase throughput for heavy traffic, then throughput is improved, but dynamic adaptation capability deteriorates because UEs cannot receive DCI to dynamically determine UL-DL subframe configuration

Engineering Contradiction:
ImprovethroughputVSAvoiddynamic adaptation capability
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent segments radio frames into two types: Type 1 frames that support dynamic adaptation with DCI monitoring, and Type 2 frames that can use candidate subframe configurations for optimized throughput. This segmentation allows the system to apply different configuration strategies to different frames, resolving the contradiction between throughput optimization and dynamic adaptation capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic frame type indication where the network can signal to UEs which radio frames are Type 1 or Type 2 frames. This dynamic indication allows the system to flexibly switch between adaptive and optimized configurations based on traffic conditions, maintaining both throughput optimization and adaptation capability.

Inventive Principle:
Principle #15Dynamics

2Productivity

If all subframes are configured as UL subframes to increase UL throughput, then UL throughput is improved, but PRACH opportunities are reduced

Engineering Contradiction:
ImproveUL throughputVSAvoidPRACH opportunities
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent segments the radio frame structure to ensure that even when candidate subframe configurations are applied, certain subframes are reserved for downlink purposes including PRACH. This segmentation guarantees that UL throughput can be optimized while PRACH opportunities are preserved.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies candidate subframe configurations in advance for specific radio frames while ensuring that necessary downlink subframes for PRACH are pre-reserved. This preliminary configuration allows the system to optimize UL throughput without compromising random access capabilities.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If candidate subframe configurations are applied to all radio frames, then throughput is maximized, but measurement capabilities deteriorate due to insufficient downlink subframes

Engineering Contradiction:
ImprovethroughputVSAvoidmeasurement capabilities
Core Design Contradiction:
ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent segments radio frames into measurement-friendly Type 1 frames and throughput-optimized Type 2 frames. Type 1 frames maintain sufficient downlink subframes for measurements while Type 2 frames focus on throughput optimization. This segmentation resolves the contradiction between maximizing throughput and maintaining measurement capabilities.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements periodic alternation between Type 1 and Type 2 frames, ensuring that measurements can be performed periodically in Type 1 frames while throughput is optimized in Type 2 frames. This periodic structure maintains both measurement capabilities and high throughput.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3111698B1New TDD configurations and eimta in LTE
Publication Date: 2019.10.02 QUALCOMM INC
  • EP3111698B1 patent drawingFigure 1
  • EP3111698B1 patent drawingFigure 2
  • EP3111698B1 patent drawingFigure 3

AI summary

A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus configures a radio frame with a subframe configuration based on a restriction, the radio frame being part of a sequence of a plurality of radio frames. The restriction excludes the radio frame from conforming to a set of subframe configurations based on at least one of a position of the radio frame within the sequence of radio frames or a type of information to be transmitted or received in the radio frame. The apparatus then communicates with a user equipment (UE) during the radio frame based on the subframe configuration.