LTE Base Station Channel Loss Determination via Random Access Preambles

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Solution Overview

Problem

In LTE networks, especially for Machine-Type Communications (MTC), there is a challenge in determining channel loss between base stations and MTC User Equipment (UE) due to severe path loss, particularly in environments like basements or buildings with thick walls, leading to poor communication quality, and existing solutions do not effectively enhance coverage without adding new relay devices.

Innovation Solution

A method that involves a base station and user equipment for determining channel loss by receiving and processing information related to the rank of channel loss extent, using random access preambles and transmission types to classify channel loss into ranks, and configuring random access preamble groups and transmission parameters to improve communication quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If operators add new sites and relay devices to enhance coverage, then coverage area is improved, but device complexity and cost increase

Engineering Contradiction:
Improvecoverage areaVSAvoiddevice complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent changes the parameter of random access preamble format (length, cyclic prefix type) based on channel loss conditions. UEs in severe coverage areas use longer preambles with extended cyclic prefixes, allowing the system to adapt to different propagation conditions without adding physical infrastructure, thus improving coverage while avoiding increased device complexity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent segments the random access preamble into different formats and types based on channel loss thresholds. By dividing preambles into multiple categories (short/long, different cyclic prefix types), the system enables UEs to select appropriate formats for their specific channel conditions, resolving the contradiction between coverage enhancement and system complexity

Inventive Principle:
Principle #1Segmentation

2Device complexity

If operators use existing LTE infrastructure without adding relay devices, then device complexity is reduced, but coverage enhancement capability is insufficient

Engineering Contradiction:
Improvedevice complexityVSAvoidcoverage area
Core Design Contradiction:
Device complexityVSArea of stationary object

Solution Approach 1:

The patent introduces dynamic adaptation where UEs and base stations adjust random access parameters based on measured channel loss. The system dynamically selects preamble formats and power levels according to real-time channel conditions, enabling existing infrastructure to adaptively serve extended coverage areas without adding relay devices

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements preliminary channel loss measurement and classification before random access. UEs measure downlink reference signals, determine their channel loss rank, and pre-select appropriate preamble formats. This preliminary action enables the system to prepare optimal access parameters in advance, allowing existing infrastructure to effectively handle severe coverage scenarios

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If base stations use traditional random access procedures, then system simplicity is maintained, but channel loss determination capability is lost

Engineering Contradiction:
Improvesystem simplicityVSAvoidchannel loss information
Core Design Contradiction:
Device complexityVSLoss of information

Solution Approach 1:

The patent establishes a feedback mechanism where UEs report their channel loss rank to the base station through the random access procedure. The base station uses this feedback information to adjust downlink transmission parameters, creating a closed-loop system that maintains relative simplicity while enabling channel loss determination and adaptation

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent uses the random access preamble as an intermediary carrier for channel loss information. Instead of requiring separate dedicated signaling, the system embeds channel loss rank indication within the random access procedure itself, maintaining system simplicity while enabling the base station to obtain channel loss information for transmission optimization

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3761746B1Method, base station, and user equipment for determining channel loss
Publication Date: 2022.08.17 HUAWEI TECH CO LTD
  • EP3761746B1 patent drawingFigure 1~3
  • EP3761746B1 patent drawingFigure 4~6
  • EP3761746B1 patent drawingFigure 7~10

AI summary

The present application discloses a method, a base station, and a user equipment for determining channel loss, where the method includes: receiving first information that is from a first user equipment UE and corresponds to a rank of a channel loss extent of the first UE; and determining the rank of the channel loss extent of the first UE according to the first information. In the present application, a base station can learn a rank of a channel loss extent of a first UE, so as to perform data transmission according to the rank, thereby improving the quality of communications between the base station and the first UE.