Adaptive Multiple Access in Integrated Access and Backhaul Networks

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Solution Overview

Problem

Current non-orthogonal multiple access (NOMA) systems face challenges in implementing advanced receivers for multiuser signal separation, synchronization, and higher signal decoding delays, particularly in integrated access and backhaul (IAB) networks where backhaul links are bottlenecks, requiring improved data transmission schemes to meet high data rate requirements.

Innovation Solution

An adaptive IAB network that dynamically switches between NOMA and orthogonal multiple access (OMA) schemes based on data rate requirements, optimizing power levels, beamforming, and transmit/receive timing to pair UEs with APs, allowing for efficient resource allocation and reduced complexity by using NOMA only when necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If NOMA scheme is used to improve data rate, then achievable data rate increases, but receiver complexity and synchronization difficulty increase

Engineering Contradiction:
Improveachievable data rateVSAvoidreceiver complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements dynamic switching between NOMA and OMA schemes based on real-time channel conditions and data rate requirements. The system adapts the multiple access scheme dynamically, selecting NOMA when high data rates are needed and channel conditions permit, and switching to OMA when complexity constraints arise or channel conditions deteriorate, thus resolving the contradiction between achievable data rate and receiver complexity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters by adjusting power allocation coefficients and resource block assignments based on channel state information. By dynamically modifying these parameters, the system optimizes the trade-off between data rate performance and implementation complexity, allowing NOMA to achieve high rates when parameters are favorable while avoiding excessive complexity when they are not

Inventive Principle:
Principle #35Parameter changes

2Productivity

If NOMA scheme is used to increase data rate, then spectrum efficiency improves, but signal decoding delay increases

Engineering Contradiction:
Improvespectrum efficiencyVSAvoidsignal decoding delay
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent employs dynamic scheme selection that considers not only data rate requirements but also latency-sensitive application requirements. For delay-sensitive traffic, the system may prefer OMA or use NOMA with simplified processing, while for delay-tolerant traffic, full NOMA processing is applied to maximize spectrum efficiency, thus balancing spectral efficiency and decoding delay based on real-time requirements

Inventive Principle:
Principle #15Dynamics

3Productivity

If NOMA is used for backhaul links to meet high data rate requirements, then data rate increases, but implementation complexity increases

Engineering Contradiction:
Improvedata rateVSAvoidimplementation complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the network into different functional domains, applying NOMA selectively to specific link types and traffic flows rather than uniformly across the entire backhaul network. By segmenting the application of NOMA to only those links and traffic types that benefit most from its high data rate capability, the system achieves improved data rates where needed while avoiding unnecessary complexity in other parts of the network

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system designs a unified multiple access framework that encompasses both OMA and NOMA schemes, allowing the same infrastructure to support multiple access modes. This multi-functional approach enables the network to switch between OMA and NOMA based on requirements, achieving high data rates when NOMA is applied while maintaining the simplicity of OMA elsewhere, thus resolving the complexity-data rate trade-off

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

Data Source

PatentEP3735755B1An adaptive multiple access scheme in integrated access and backhaul networks
Publication Date: 2023.08.09 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3735755B1 patent drawingFigure 1A~1B
  • EP3735755B1 patent drawingFigure 2A~2C
  • EP3735755B1 patent drawingFigure 3

AI summary

A method for integrating access and backhaul links, the method includes: obtaining information indicating a data rate requirement for a link between a first AP and a second AP; obtaining information indicating a gain of the link between the first AP and the second AP; computing, using the gain of the link, an achievable data rate for the link between the first AP and the second AP, wherein the achievable data rate is computed based on an OMA scheme; determining that the data rate requirement is greater than the achievable data rate; and as a result of determining that the data rate requirement is greater than the achievable data rate, pairing a first UE with the first AP, such that a NOMA scheme is used for the link between the first AP and second AP and the link between the first AP and the first UE.