NB-IoT Uplink Resource Allocation via Tone Group Segmentation

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Solution Overview

Problem

The existing LTE system faces challenges in accurately allocating resources for uplink transmission in Narrowband Internet of Things (NB-IoT) devices, particularly due to their low data transmission rates, low latency requirements, and limited mobility, which are exacerbated by penetration losses in building environments, necessitating a more precise resource indication method.

Innovation Solution

The method involves generating and sending first and second indication information by a base station for uplink transmission resource allocation, using tone groups as the minimum granularity, which can include single-tone or multi-tone scenarios, allowing for hybrid multi-tone transmission modes and enabling the UE to allocate resources effectively for NB-PUCCH and NB-PUSCH channels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If PRB (physical resource block) is used as the minimum granularity for resource allocation in existing LTE system, then resource allocation is simplified and device complexity is reduced, but resource allocation accuracy is insufficient for NB-IoT devices with 180 kHz RF bandwidth

Engineering Contradiction:
Improveresource allocation accuracyVSAvoidresource indication complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The PRB is segmented into multiple tone groups, where each tone group contains a subset of subcarriers. This segmentation allows for finer-grained resource allocation (at the tone group level rather than full PRB level) while maintaining a manageable indication structure through bitmap representation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimension of resource indication by using bitmap fields to represent tone group allocations within PRBs. This transforms the resource allocation indication from a coarse PRB-level granularity to a fine tone-group-level granularity, enabling precise allocation for NB-IoT's 180 kHz bandwidth while keeping the indication compact through binary bitmap representation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Device complexity

If NB-IoT UE supports only 180 kHz RF bandwidth (one PRB size), then device complexity and power consumption are reduced, but resource allocation accuracy deteriorates due to lack of finer granularity indication method

Engineering Contradiction:
Improvedevice complexityVSAvoidresource indication precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The PRB is segmented into multiple tone groups, where each tone group contains a subset of subcarriers. This segmentation allows for finer-grained resource allocation (at the tone group level rather than full PRB level) while maintaining a manageable indication structure through bitmap representation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a new dimension of resource indication by using bitmap fields to represent tone group allocations within PRBs. This transforms the resource allocation indication from a coarse PRB-level granularity to a fine tone-group-level granularity, enabling precise allocation for NB-IoT's 180 kHz bandwidth while keeping the indication compact through binary bitmap representation.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Adaptability or versatility

If MTC equipments are deployed in poor network coverage areas (basement, behind insulation foil, metal window, thick wall), then Internet of Everything coverage is improved, but penetration losses increase causing lower data transmission rates

Engineering Contradiction:
Improvecoverage area adaptabilityVSAvoiddata transmission rate
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent changes the resource allocation granularity parameter from PRB level to tone group level, enabling more precise resource assignment. This allows for optimized resource utilization in NB-IoT's narrow 180 kHz bandwidth, improving spectral efficiency and data transmission rates in challenging coverage conditions by eliminating waste from coarse-grained allocation.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3402273B1Uplink transmission resource allocation method, base station, and user equipment
Publication Date: 2020.11.25 SHARP KK
  • EP3402273B1 patent drawingFigure 1
  • EP3402273B1 patent drawingFigure 2
  • EP3402273B1 patent drawingFigure 3

AI summary

The present invention provides a method executed by a base station, comprising: generating a first indication and a second indication for uplink transmission resource allocation for a tone group, wherein the tone group is used as a resource allocation unit and comprises one or more tones; and sending to a UE an RRC message including the first indication, and sending to the UE downlink control information carried by an NB-PDCCH, wherein the downlink control information includes the second indication. Accordingly, the present invention further provides a method executed by a user equipment, the method comprising: receiving, from a base station, an RRC message, wherein the RRC message comprises a first indication for uplink transmission resource allocation for a tone group; receiving, from the base station, downlink control information carried by an NB-PDCCH, wherein the downlink control information comprises a second indication for uplink transmission resource allocation for the tone group; and allocating resources for uplink transmission according to the first indication and the second indication. The present invention further provides a base station and a UE respectively executing the above-described methods.