Scalable Bandwidth Allocation in OFDMA Radio Networks

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Solution Overview

Problem

Radio telecommunications networks face challenges in supporting UEs with varying reception bandwidths and efficient bandwidth sharing across different transmission bandwidths, particularly in scenarios where not all cells are upgraded to full capacity or where spectrum availability is limited.

Innovation Solution

The implementation of OFDMA systems with frequency domain multiplexing and inverse fast Fourier transform (IFFT) for signal processing, allowing UEs with different reception bandwidths to operate within the network by allocating sub-carriers based on their capabilities, and using a common band for synchronization and broadcast channels to manage UE transitions between idle and active states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If OFDMA systems implement maximum downlink transmission bandwidth of 20 MHz to meet high data rate requirements, then data rate is improved, but device complexity increases due to UE receiver bandwidth limitations

Engineering Contradiction:
Improvedata rateVSAvoidUE receiver complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the 20 MHz transmission bandwidth into multiple smaller bandwidth portions (e.g., 5 MHz, 10 MHz) that can be independently allocated to different UEs. This allows the base station to serve UEs with varying reception capabilities by assigning appropriate bandwidth segments, thereby maintaining high data rates for capable UEs while avoiding the complexity of requiring all UEs to support full 20 MHz bandwidth.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic bandwidth allocation where the base station can flexibly adjust the transmission bandwidth assigned to each UE based on their individual reception capabilities. The system transitions from a static fixed bandwidth approach to a dynamic adaptive approach, allowing the network to optimize performance while accommodating varying UE complexities in real-time.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the network supports multiple transmission bandwidths (5 MHz, 10 MHz, 15 MHz, 20 MHz) to accommodate different UE capabilities, then adaptability is improved, but device complexity increases at the base station

Engineering Contradiction:
ImproveUE capability supportVSAvoidbase station complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a universal base station design that can handle multiple transmission bandwidths (5 MHz, 10 MHz, 15 MHz, 20 MHz) using a common processing framework. The base station employs a single IFFT processor that can operate with different bandwidth configurations, and uses unified control mechanisms to manage UEs with varying capabilities, thereby achieving multi-functionality without proportionally increasing complexity.

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

Solution Approach 2:

The patent utilizes parameter changes in the IFFT processing to accommodate different transmission bandwidths. By adjusting parameters such as the number of sub-carriers and resource block configurations within the same IFFT framework, the base station can dynamically support multiple bandwidth modes (5 MHz, 10 MHz, 15 MHz, 20 MHz) without requiring separate processing paths for each bandwidth type.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If the base station uses a single IFFT processor for all bandwidth configurations, then device complexity is reduced, but manufacturing precision requirements increase for frequency domain multiplexing

Engineering Contradiction:
Improvebase station processor complexityVSAvoidfrequency alignment precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent segments the frequency domain into distinct sub-carrier groups that can be independently allocated to different UEs with different bandwidth requirements. By organizing the frequency resources into discrete, manageable segments within a single IFFT processor, the system achieves efficient frequency domain multiplexing while maintaining manufacturing precision through standardized sub-carrier spacing and defined frequency grids.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP1977544B1Method and system for supporting scalable bandwidth
Publication Date: 2019.05.22 NEC CORP
  • EP1977544B1 patent drawingFigure 1
  • EP1977544B1 patent drawingFigure 2
  • EP1977544B1 patent drawingFigure 3

AI summary

Methods and systems for supporting scalable bandwidth in radio telecommunications networks are provided. When signals are transmitted to user equipments using a transmitter of a radio telecommunication network, the signals are frequency multiplexed, each signal lying within a frequency band having an equal or narrower bandwidth than a reception bandwidth of each user equipment that is to receive a signal. Then the multiplexed signal is converted to a time domain signal.