LTE Base Station Timing Adjustment for Uu and Ud Interface Coordination

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

In LTE mobile communication systems, mobile stations in the same cell cannot simultaneously transmit/receive data signals and control signals through the Uu interface and inter-mobile station interfaces at the same frequency, requiring adjustments in transmission/reception timing.

Innovation Solution

A mobile communication method where a radio base station allocates opportunities for data signal transmission/reception through the Uu interface and inter-mobile station interface using common identification information, and transmits direction information to adjust the transmission direction, reducing signaling overhead and enabling simultaneous operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If mobile stations use identical frequencies for both Uu interface (base station communication) and Ud interface (inter-mobile station communication), then communication efficiency is improved, but transmission/reception timing conflicts occur between the two interfaces

Engineering Contradiction:
Improvecommunication efficiencyVSAvoidtiming coordination
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements dynamic timing adjustment where the base station determines and notifies specific transmission/reception timing for Ud interface data signals based on PDCCH allocation. The timing is dynamically adapted to avoid conflicts with Uu interface operations, allowing flexible scheduling that resolves the contradiction between using identical frequencies and maintaining proper timing coordination.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If separate identification information is used for allocating Ud interface resources to different mobile stations, then resource allocation precision is improved, but signaling overhead increases

Engineering Contradiction:
Improveresource allocation precisionVSAvoidsignaling overhead
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent employs a common identification information (such as a group RNTI) that is shared between multiple mobile stations for allocating Ud interface data transmission/reception opportunities. This single identification serves multiple mobile stations simultaneously, reducing signaling overhead while maintaining sufficient allocation precision through the base station's ability to determine specific timing for each station based on their individual PDCCH allocations.

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

Data Source

PatentEP2712251B1Mobile communication method and wireless base station
Publication Date: 2017.08.02 NTT DOCOMO INC
  • EP2712251B1 patent drawingFigure 1~2
  • EP2712251B1 patent drawingFigure 3
  • EP2712251B1 patent drawingFigure 4

AI summary

Transmission/reception timing of a data signal and a control signal through a Uu interface and transmission/reception timing of the data signal through a Ud interface are properly adjusted. A mobile communication method according to the present invention includes: a step A in which a radio base station eNB notifies a mobile station UE#1 and a mobile station UE#2 that an opportunity to transmit and receive the data signal through the Ud interface is allocated through a PDCCH in which an X-RNTI is used; and a step B in which the radio base station eNB transmit "direction information", for notifying of a direction in which the data signal should be transmitted in the opportunity, to the mobile station UE#1 and the mobile station UE#2.