Base Station Control Signal Multiplexing for LTE and IMT-A Coexistence

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Solution Overview

Problem

Efficient transmission of control signals across multiple co-existing old and new mobile communications systems while maintaining backward compatibility is not adequately addressed in current technologies.

Innovation Solution

The solution involves a base station apparatus and user apparatus that utilize orthogonal frequency division multiplexing and time division multiplexing schemes to channel code and multiplex control signals for LTE and IMT-A systems, allowing for efficient transmission and decoding of control signals within specific bandwidths, ensuring compatibility and error correction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple old and new mobile communications systems co-exist in the same region, then system versatility and backward compatibility are improved, but control signal transmission efficiency and system complexity deteriorate

Engineering Contradiction:
Improvesystem compatibilityVSAvoidcontrol signal transmission
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments control signals by dividing them into system-specific components (LTE control signals and IMT-A control signals) that are transmitted separately in different frequency bands or time slots. This allows each system to process its own control signals independently while co-existing in the same region, resolving the complexity issue of managing multiple systems simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts and separates control signal processing from the general communication framework by dedicating specific frequency resources and time slots to each system's control signals. This extraction allows legacy systems to maintain their control signal structures while new systems implement advanced control mechanisms, thereby maintaining backward compatibility without overwhelming system complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

2Adaptability or versatility

If control signals are transmitted for both LTE and IMT-A systems simultaneously, then system versatility is improved, but signal transmission efficiency and interference management worsen

Engineering Contradiction:
Improvemulti-system supportVSAvoidcontrol signal transmission efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent merges LTE and IMT-A systems into a unified frequency overlay architecture where both systems operate simultaneously in overlapping frequency bands. Control signals for both systems are transmitted through a combined framework that allocates specific time-frequency resources to each system, enabling multi-system support while managing transmission efficiency through coordinated resource allocation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces additional dimensions for control signal transmission by utilizing both frequency division multiplexing (different frequency bands for different systems) and time division multiplexing (different time slots for control signals). This multi-dimensional approach allows simultaneous transmission of LTE and IMT-A control signals without excessive interference, maintaining transmission efficiency while supporting multiple systems.

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

Data Source

PatentEP2271150B1Base station device, user device, and method used in mobile communication system
Publication Date: 2018.05.02 NTT DOCOMO INC
  • EP2271150B1 patent drawingFigure 1
  • EP2271150B1 patent drawingFigure 2
  • EP2271150B1 patent drawingFigure 3

AI summary

A base station apparatus is used in a region in which a first system and a second system co-exist. In the first system, mobile communication is conducted using a variable system bandwidth not more than a basic bandwidth. In the second system, mobile communication is conducted using a variable system bandwidth which is not more than a bandwidth of an advanced system band which is at least as wide as multiple of the basic bandwidths. The base station apparatus generates a control signal for the first system and a control signal for the second system, orthogonally multiplexes them, and includes the same in a downlink signal to transmit the downlink signal. The advanced system band is divided such that it includes multiple of areas (P, Q, R, S) of the basic bandwidth. The control signal for the first system is included in one of the areas (Q). The control signal for the second system is included in at least one of the areas (P, Q, R, S).