Base Station Downlink Coverage Enhancement via TTI Segmentation

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Solution Overview

Problem

Low-power nodes in mobile communication systems have limited downlink coverage due to smaller downlink coverage areas compared to uplink coverage, making it difficult to effectively transmit control and data information to distant user equipment.

Innovation Solution

A method for expanding downlink coverage by performing coverage enhancement processing on control and data information at base stations, which includes extending time and frequency domain resources and enhancing transmit power for physical resource elements, and transmitting coverage enhancement indication information to user equipment to facilitate the acquisition of these enhanced resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If low-power nodes increase transmit power to expand downlink coverage, then coverage area increases, but energy consumption increases and power constraints are violated

Engineering Contradiction:
Improvedownlink coverage areaVSAvoidenergy consumption
Core Design Contradiction:
Area of stationary objectVSUse of energy by moving object

Solution Approach 1:

The downlink transmission is segmented into multiple transmission time intervals (TTIs) where the same data is transmitted repeatedly across different time resources. This time-domain segmentation allows distant UEs to accumulate signal energy through repeated receptions without requiring the base station to continuously transmit at high power levels.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements periodic transmission of downlink data across multiple TTIs, where control information and data are transmitted in a periodic pattern. This periodic action enables distant UEs to capture signals at optimal moments within each period while maintaining energy efficiency through structured transmission cycles rather than continuous high-power transmission.

Inventive Principle:
Principle #19Periodic action

2Length of moving object

If low-power nodes extend coverage to distant UEs, then coverage range increases, but signal quality and reliability deteriorate

Engineering Contradiction:
Improvecoverage rangeVSAvoidsignal quality
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

Control information is segmented and transmitted through multiple channels (PCFICH for control format, PDCCH for downlink control, PHICH for HARQ feedback) across different frequency and time resources. This segmentation ensures that even if some transmissions are corrupted by fading or interference, distant UEs can reliably acquire control information through alternative paths.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements HARQ feedback mechanisms where UEs send acknowledgment information back to the base station through uplink channels. This feedback loop allows the base station to detect transmission failures and retransmit data, significantly improving reliability for distant UEs experiencing poor channel conditions.

Inventive Principle:
Principle #23Feedback

3Area of stationary object

If downlink resources are extended to cover distant UEs, then coverage area increases, but uplink-downlink coverage balance deteriorates

Engineering Contradiction:
Improvedownlink coverage areaVSAvoiduplink-downlink coverage balance
Core Design Contradiction:
Area of stationary objectVSAdaptability or versatility

Solution Approach 1:

The patent dynamically adjusts the number of transmission time intervals and resource allocations based on UE distance and channel conditions. For distant UEs requiring coverage enhancement, the system activates extended TTI bundling and increased resource allocation, while nearby UEs use standard configurations. This dynamic adaptation maintains uplink-downlink balance by applying enhancement only where needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Coverage enhancement resources are allocated locally to specific distant UEs rather than uniformly across all users. The system identifies UEs experiencing coverage issues and applies enhanced resource allocation, extended TTI bundling, and power boosting specifically to those users, maintaining efficient resource utilization and uplink-downlink balance for the overall cell.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2822331B1Information transmission method and base station
Publication Date: 2020.10.28 HUAWEI TECH CO LTD
  • EP2822331B1 patent drawingFigure 1~3
  • EP2822331B1 patent drawingFigure 4~6
  • EP2822331B1 patent drawingFigure 7~9

AI summary

The present invention provides a method for information transmission, a base station and a user equipment. The method for information transmission includes: performing a coverage enhancement processing on control information and data information (101); transmitting the control information and the data information, which the coverage enhancement processing is performed on, to a user equipment (102); and transmitting coverage enhancement indication information to the user equipment, where the coverage enhancement indication information is used for indicating the user equipment to acquire the control information and the data information which the coverage enhancement processing is performed on (103). The base station includes: a processing module, configured to perform a coverage enhancement processing on control information and data information; and a transmitting module, configured to transmit the control information and the data information which the coverage enhancement processing is performed on to a user equipment, and transmit coverage enhancement indication information to the user equipment, where the coverage enhancement indication information is at least used for indicating the user equipment to acquire the control information and the data information which the coverage enhancement processing is performed on. The technical solutions of the present invention are capable of improving the downlink coverage range.