LTE-NR Resource Reservation via Absolute Frequency Indication

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Solution Overview

Problem

In wireless communications, especially when both LTE and 5G NR are deployed, signal interference occurs, making it difficult for terminal devices to accurately reserve resources due to inconsistent reference signal locations across different frequency bands, particularly due to the center subcarrier alignment issue between LTE and NR systems.

Innovation Solution

The method involves a network device generating and sending indication information that includes frequency location and bandwidth information to a terminal device, allowing it to determine the precise location of resources to be reserved in the NR system by aligning subcarriers and resource blocks, thereby resolving the inconsistency caused by the center subcarrier shift.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the terminal device uses frequency shift and antenna port quantity to determine resource location, then the resource reservation can be made, but the resource location determination becomes inaccurate due to center subcarrier alignment differences between LTE and NR systems

Engineering Contradiction:
Improveresource reservation accuracyVSAvoidresource location determination accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent changes the parameter representation from relative frequency shift to absolute frequency location. The network device indicates the absolute frequency location of the first subcarrier (corresponding to LTE center subcarrier) and the bandwidth, allowing the terminal to calculate precise resource locations in both LTE and NR systems without ambiguity caused by center subcarrier alignment differences.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces an intermediary reference point - the first subcarrier of the second system (NR) that corresponds to the center subcarrier of the first system (LTE). By indicating the absolute frequency location of this intermediary subcarrier and the bandwidth, the system enables accurate determination of resource locations that need to be reserved, resolving the alignment inconsistency between the two systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the center subcarrier is not counted as an RB subcarrier in LTE but is counted in NR, then the resource block alignment becomes inconsistent, but this causes different subcarrier shifts on left and right sides of the center subcarrier

Engineering Contradiction:
Improveresource block alignment flexibilityVSAvoidsubcarrier shift consistency
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent changes from using relative frequency shift parameters to absolute frequency location parameters. By indicating the absolute frequency location of the first subcarrier and the bandwidth, the terminal can independently calculate the correct subcarrier shifts for both left and right sides of the center subcarrier, eliminating the inconsistency caused by different RB alignment rules in LTE and NR.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If the terminal device reserves NR resource at LTE reference signal locations, then interference between LTE and NR systems is reduced, but the terminal cannot accurately determine the resource location due to frequency domain misalignment

Engineering Contradiction:
Improveinterference between LTE and NRVSAvoidresource location determination
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The patent uses the first subcarrier (NR system) corresponding to the LTE center subcarrier as an intermediary reference. The network device indicates the absolute frequency location of this intermediary subcarrier and the bandwidth, enabling the terminal to accurately calculate the locations of resources that need to be reserved in NR to protect LTE reference signals, thereby resolving both the interference issue and the location determination accuracy issue.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the indication parameters from relative frequency shift to absolute frequency location. By providing the absolute frequency location of the first subcarrier and the bandwidth, the terminal can accurately determine the frequency domain positions of resources to be reserved, enabling effective interference avoidance between LTE and NR systems.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3709550B1Information indication method, terminal device and network device
Publication Date: 2022.05.25 HUAWEI TECH CO LTD
  • EP3709550B1 patent drawingFigure 1~2
  • EP3709550B1 patent drawingFigure 3~4
  • EP3709550B1 patent drawingFigure 5~6

AI summary

This application discloses an information indication method, a terminal device, and a network device. The method includes: receiving, by a terminal device, indication information from a network device, where the indication information indicates at least one of frequency location information or bandwidth information, the frequency location information includes one of a number of a first subcarrier, an absolute radio frequency channel number of the first subcarrier, or a first frequency, and the bandwidth information includes one of first bandwidth, a second subcarrier quantity, a first resource block quantity, or a second resource block bitmap; and determining, by the terminal device, a first resource based on the indication information, where the first resource is a to-be-reserved resource. According to this application, reliability of a determined location of a resource that needs to be reserved in a system is improved.