Downlink Control Information Search Space Segmentation

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Solution Overview

Problem

The increasing number of user equipment (UEs) and the corresponding data and control information to be transmitted by base stations (BSs) in wireless communication systems pose a challenge due to limited radio resources, necessitating an efficient method for transmitting and receiving uplink/downlink data and control information.

Innovation Solution

The implementation of a method that allows for efficient transmission and reception of uplink/downlink signals using limited radio resources, enabling low-cost and low-complexity user equipment (UE) communication with BSs while maintaining compatibility with legacy systems, enhancing coverage, and supporting narrowband communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the number of user equipment and data transmission is increased to meet growing communication demands, then data throughput requirement is satisfied, but radio resources become insufficient and system complexity increases

Engineering Contradiction:
Improvedata throughputVSAvoidradio resources
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent segments the downlink control information transmission by introducing two separate search spaces: common search space for common DCI and user-specific search space for user-specific DCI. This segmentation allows efficient resource utilization by directing different types of control information to appropriate search spaces, thereby satisfying increased data throughput requirements without proportionally increasing overall radio resource consumption.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimension in control information organization by defining search spaces in the time-frequency domain with specific aggregation levels. This dimensional approach allows multiple UEs to share radio resources efficiently through differentiated search space configurations, resolving the contradiction between serving more UEs and maintaining limited radio resource availability.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If advanced communication technologies like carrier aggregation and MIMO are deployed to increase data capacity, then data throughput is improved, but device complexity and implementation cost increase

Engineering Contradiction:
Improvedata capacityVSAvoidUE implementation complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments control information processing into common and user-specific components with different aggregation levels. Low-complexity UEs can be configured to monitor only common search space with lower aggregation levels, reducing their implementation complexity while still benefiting from advanced technologies like carrier aggregation and MIMO that are managed through the network's sophisticated resource allocation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by allowing different UEs to have different search space configurations and aggregation level requirements. This enables low-complexity UEs to operate with simplified monitoring while high-complexity UEs can utilize full capabilities, thereby supporting advanced technologies without requiring all devices to be complex.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If more control information is transmitted to serve increasing number of UEs, then service coverage is improved, but resource consumption and interference increase

Engineering Contradiction:
Improveservice coverageVSAvoidradio resource consumption
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent merges common control information and user-specific control information into a unified PDCCH structure with differentiated search spaces. This merging allows efficient resource utilization by combining the benefits of common resource allocation with personalized user scheduling, improving service coverage without proportionally increasing total control information overhead and radio resource consumption.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3172856B1Method and user equipment for receiving downlink control information, and method and base station for transmitting downlink control information
Publication Date: 2021.06.02 LG ELECTRONICS INC
  • EP3172856B1 patent drawingFigure 1(a)~1(b)
  • EP3172856B1 patent drawingFigure 2
  • EP3172856B1 patent drawingFigure 3(a)~3(b)

AI summary

A search space (hereinafter, CSS) for a control channel for scheduling a random access response may be configured by a system information block. A user equipment (UE) may attempt to receive a control channel for a random access response on the assumption that CSS is configured in accordance with a configuration based on the system information block. The UE may attempt to receive the control channel within a UE-specific search space (USS) by assuming that the USS is configured in accordance with the configuration of the CSS until a configuration for the USS is received.