Control-less Subframes for Wireless Downlink Blind Decoding

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Solution Overview

Problem

Current wireless communication systems face inefficiencies in downlink control signal management, particularly in multiple-carrier implementations, where blind decoding operations are resource-intensive and increase processing overhead for mobile entities without corresponding benefits in control signaling.

Innovation Solution

Implementing control-less subframes, specifically Almost Blank Subframes, where designated subframes are devoid of downlink control signals, allowing mobile entities to reduce blind decoding operations and allocate resources more efficiently by providing explicit or implicit indications for identifying these subframes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If control signals are transmitted in every subframe, then control signaling completeness is improved, but processing overhead at mobile entities increases

Engineering Contradiction:
Improvecontrol signaling completenessVSAvoidprocessing overhead at mobile entities
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments subframes into two types: control subframes (with downlink control signals) and control-less subframes (without downlink control signals). This segmentation allows mobile entities to selectively perform blind decoding operations only in control subframes, reducing processing overhead while maintaining control signaling completeness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements periodic transmission of control signals in designated control subframes rather than continuously in every subframe. The network entity configures and indicates patterns of control-less subframes to mobile entities, creating a periodic structure where control signals appear at regular intervals, thereby reducing mobile entity processing while ensuring control information delivery.

Inventive Principle:
Principle #19Periodic action

2Reliability

If blind decoding operations are performed in all subframes, then control signal detection reliability is improved, but resource efficiency deteriorates

Engineering Contradiction:
Improvecontrol signal detection reliabilityVSAvoidresource efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent extracts control signals from certain subframes to create control-less subframes. By removing control signals from specific subframes and concentrating them in designated control subframes, the patent enables mobile entities to skip blind decoding in control-less subframes, improving resource efficiency while maintaining detection reliability in control subframes.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The network entity performs preliminary action by configuring and indicating the pattern of control-less subframes to mobile entities before data transmission begins. This preliminary configuration allows mobile entities to anticipate which subframes require blind decoding and which do not, optimizing resource allocation and improving overall system productivity.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If control-less subframes are implemented, then resource allocation efficiency is improved, but device complexity at base station increases

Engineering Contradiction:
Improveresource allocation efficiencyVSAvoiddevice complexity at base station
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary indication mechanism where the network entity provides configuration information about control-less subframe patterns to mobile entities. This intermediary layer manages the complexity at the base station by using standardized indication methods, allowing resource allocation efficiency to improve without excessive base station complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2732574B1Downlink control with control-less subframes
Publication Date: 2019.08.21 QUALCOMM INC
  • EP2732574B1 patent drawingFigure 1
  • EP2732574B1 patent drawingFigure 2
  • EP2732574B1 patent drawingFigure 3

AI summary

In a wireless communications system wherein control-less subframes share a common carrier with subframes that include control signaling, a method performed by a base station may include receiving a first indication from a network entity to maintain a designated set of subframes on a common carrier devoid of designated downlink control signals. The method may further include providing a second indication in a wireless transmission to a mobile entity, the second indication enabling identification of subframes in the designated set (i.e., the control-less subframes) by the mobile entity. In turn, identification of control-less subframes by the mobile entity prior to decoding the subframes may enable a more efficient control of blind decoding operations at the mobile entity and reduce blind decoding operations required for the mobile entity to decode downlink control information.