Radio Base Station PRS Transmission for Mobile Station Synchronization

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Solution Overview

Problem

In the current LTE-Rel. 9 scheme, mobile stations UE face complexity in configuring PRS reception due to the need to detect both Normal CP and Extended CP transmission patterns, leading to increased PRS reception processing time.

Innovation Solution

A radio base station transmits the length of the cyclic prefix used in neighboring cells, allowing mobile stations to receive a reference signal generated based on this length, enabling the measurement of propagation delay differences without requiring separate configurations for Normal and Extended CP patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If separate PRS transmission patterns are defined for Normal CP and Extended CP cases, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
ImprovePRS measurement precisionVSAvoidmobile station configuration complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent defines a unified PRS transmission pattern that can be applied to both Normal CP and Extended CP cases. The base station transmits a single PRS pattern configuration that works universally across different CP types, eliminating the need for separate pattern definitions. This universal approach maintains measurement precision while significantly reducing mobile station configuration complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

Instead of defining separate PRS transmission patterns for different CP types, the patent changes the approach by using a single pattern definition with parameters that adapt to different CP configurations. The mobile station determines the appropriate pattern based on CP length information received from the base station, rather than maintaining separate configurations for Normal and Extended CP cases.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If mobile station detects both Normal CP and Extended CP PRS patterns, then measurement precision is improved, but loss of time increases

Engineering Contradiction:
Improvepropagation delay measurement precisionVSAvoidPRS reception processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts the CP type determination logic from the PRS detection process itself. The base station explicitly provides CP length information to the mobile station through higher-layer signaling, allowing the mobile station to select the appropriate PRS pattern without performing exhaustive detection of both Normal CP and Extended CP patterns. This extraction of determination logic significantly reduces processing time while maintaining measurement precision.

Inventive Principle:
Principle #2Taking out (Extraction)

3Adaptability or versatility

If separate PRS transmission patterns are configured for different CP types, then adaptability is improved, but device complexity increases

Engineering Contradiction:
ImprovePRS pattern adaptabilityVSAvoidmobile station configuration
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces dynamic selection of PRS patterns based on real-time CP length information. The mobile station dynamically determines which PRS pattern to use by receiving CP length indications from the base station, rather than being statically configured with separate patterns for Normal and Extended CP. This dynamic approach provides adaptability to different CP types while simplifying the overall configuration.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2472977B1Radio base station, mobile station and measurement method
Publication Date: 2018.04.04 NTT DOCOMO INC
  • EP2472977B1 patent drawingFigure 1~2
  • EP2472977B1 patent drawingFigure 3(a)~4
  • EP2472977B1 patent drawingFigure 5

AI summary

A radio base station eNB according to the present invention includes: an upper-layer information transmission unit 11 configured to transmit a length of CP used in neighbouring cells #1 to #3; and a PRS transmission unit 12 configured to transmit, when the subordinate cell #2 is included in the neighbouring cells #1 to #3, the PRS generated based on the length of CP, in the subordinate cell #2.