PDCCH Search Space Segmentation for UE Complexity Reduction

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Solution Overview

Problem

In heterogeneous LTE networks with single cell identity, the processing complexity and power consumption for user equipment (UE) increase due to the need to blindly monitor multiple control channel search spaces, which limits the capacity and efficiency of PDCCH transmissions.

Innovation Solution

Configuring specific transmission elements for carrying control data within data transmissions, allowing UEs to focus their blind decoding efforts on predefined candidates, thereby reducing the complexity and power consumption by eliminating the need for separate control regions and enhancing PDCCH capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If UEs blindly monitor multiple control channel search spaces in heterogeneous networks with single cell identity, then control data can be transmitted flexibly across multiple points, but processing complexity and power consumption for UEs increase

Engineering Contradiction:
Improvecontrol data transmission flexibilityVSAvoidUE processing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the control channel search spaces into multiple distinct sets (first set and second set), each with specific monitoring requirements. This segmentation allows the system to maintain multiple search spaces for flexible control data transmission while providing structured organization that helps manage UE processing complexity through defined monitoring patterns and associations with different transmission points.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic search space configuration where the network can configure different sets of search spaces for different UEs based on their specific needs and the transmission point assignments. This dynamic approach allows control data transmission flexibility to adapt to changing network conditions while enabling UEs to monitor only the relevant search spaces configured for them, thereby managing processing complexity.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If UEs blindly monitor multiple control channel search spaces in heterogeneous networks with single cell identity, then control data can be transmitted flexibly across multiple points, but power consumption for UEs increases

Engineering Contradiction:
Improvecontrol data transmission flexibilityVSAvoidUE power consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

By segmenting search spaces into multiple configured sets with specific associations to transmission points, the patent enables UEs to identify and monitor only the relevant search spaces for their assigned transmission points. This segmentation reduces the effective number of search spaces each UE must monitor compared to a blanket monitoring approach, thereby reducing power consumption while preserving control data transmission flexibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent enables UEs to self-configure their monitoring behavior based on received configuration information that associates specific search spaces with specific transmission points. Each UE autonomously determines which search spaces to monitor based on its assigned transmission points, eliminating the need to blindly monitor all possible search spaces and thereby reducing power consumption while maintaining the ability to receive control data from multiple points.

Inventive Principle:
Principle #25Self-service

3Reliability

If separate control regions are used for control data transmission, then control data can be clearly separated from user data, but PDCCH capacity is limited

Engineering Contradiction:
Improvecontrol data separationVSAvoidPDCCH capacity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent merges control data transmission with user data transmission by allowing control data to be transmitted within the same physical downlink shared channel (PDSCH) resources that carry user data. This merging eliminates the need for separate dedicated control regions, thereby increasing PDCCH capacity and resource utilization efficiency while maintaining reliable control data transmission through the use of multiple configured search spaces that provide clear logical separation and identification of control data locations.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3386139B1Transmission and reception of control data in a communications system
Publication Date: 2021.09.22 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3386139B1 patent drawingFigure 1~3
  • EP3386139B1 patent drawingFigure 4~6
  • EP3386139B1 patent drawingFigure 7~8

AI summary

A method (1200) for transmission of control data to a user equipment (904) in a mobile telecommunication system (900), wherein the method (1200) comprises sending (1220) control data to the user equipment (904) in a data transmission (600, 700, 800, 1300, 1400), and performing, by the user equipment (904), a blind decoding (1260) of transmission elements within the data transmission (600, 700, 800, 1300, 1400) in order to detect the control data in a data region (604) in the data transmission (600, 700, 800, 1300, 1400).