E-PDCCH Antenna Port Determination for MU-MIMO Collision Avoidance

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Solution Overview

Problem

In enhanced wireless communication systems, determining a resource for ACK/NACK transmission and accurately identifying an antenna port for E-PDCCH is challenging, particularly when multiple users are supported using MU-MIMO, leading to potential collisions and inefficient operations.

Innovation Solution

The method involves determining an antenna port for the E-PDCCH based on the index of a control channel element derived from a UE's identifier, allowing for precise mapping and demodulation of the DL control channel, thereby avoiding resource collisions and ensuring appropriate transmission and reception.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple users are supported using MU-MIMO, then system capacity and user support are improved, but resource collisions and interference increase

Engineering Contradiction:
Improvesystem capacityVSAvoidresource collision
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies local quality by assigning different antenna ports to different resource regions (localized vs distributed E-PDCCH regions). This allows each user equipment to be associated with a specific antenna port based on its resource allocation, enabling multiple users to operate simultaneously without resource collisions while maintaining MU-MIMO capacity

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the parameter of antenna port identification by deriving it from the lowest eCCE index. This parameter change enables systematic differentiation of resources among multiple users, resolving collisions while supporting enhanced system capacity through MU-MIMO operations

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If antenna ports are assigned based on resource regions, then accurate demodulation is improved, but system complexity increases

Engineering Contradiction:
Improvedemodulation accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies self-service by enabling user equipment to autonomously determine its antenna port based on the lowest eCCE index of its assigned resource region. This self-determination mechanism improves demodulation accuracy without requiring complex centralized coordination, thereby limiting the increase in system complexity

Inventive Principle:
Principle #25Self-service

3Productivity

If resource allocation is optimized for MU-MIMO, then transmission efficiency is improved, but resource collision risk increases

Engineering Contradiction:
Improvetransmission efficiencyVSAvoidresource collision
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent resolves resource collision by introducing an additional dimension of differentiation through antenna port assignment. While resource regions are allocated in time-frequency space, the antenna port dimension provides an extra layer of separation, allowing efficient MU-MIMO transmission without collisions

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

Data Source

PatentEP2806575B1Method and apparatus for enhanced control channel-based operation in wireless communication system
Publication Date: 2020.04.29 LG ELECTRONICS INC
  • EP2806575B1 patent drawingFigure 1(a)~1(b)
  • EP2806575B1 patent drawingFigure 2
  • EP2806575B1 patent drawingFigure 3

AI summary

The present invention relates to a wireless communication system, and more specifically, to a method and an apparatus for enhanced control channel-based operation. A method for a base station for transmitting a downlink control channel in a wireless communication system according to one embodiment of the present invention comprises the steps of: determining one antenna port to be used for the downlink control channel; mapping the downlink control channel to a resource element on the basis of a reference signal for the one antenna port; and transmitting the mapped downlink control channel to a terminal, wherein an index for the one antenna port can be determined on the basis of a control channel element (CCE) index of the downlink control channel derived from the terminal identifier.