Interlace Pattern Selection for Low CM PAPR Transmission

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Solution Overview

Problem

Current wireless communication technologies face inefficiencies when transitioning from licensed to unlicensed frequency spectra, particularly in the uplink, due to differences in absorption and regulatory requirements, which can limit transmission power and degrade performance when coexisting with other technologies like Wi-Fi.

Innovation Solution

The use of interlacing techniques for resource block allocation and clustered DFT-S-OFDM modulation in the uplink transmission, allowing for adaptable transmission characteristics and reduced Peak to Average Power Ratio (PAPR) and Cubic Metric (CM), enabling higher transmission power while meeting regulatory requirements for maximum Power Spectral Density (PSD) and bandwidth occupancy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If conventional transmission techniques are used in unlicensed spectrum, then transmission can be performed, but transmission power is limited and performance degrades due to regulatory requirements and coexistence with other technologies

Engineering Contradiction:
Improvetransmission powerVSAvoidperformance
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The transmission signal is segmented into multiple interlaced resource blocks distributed across different frequency subbands. This segmentation allows the transmission to meet PSD masks by spreading power across frequency while maintaining overall transmission power through the interlacing structure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the transmission parameters by using clustered DFT-S-OFDM modulation with specific cluster sizes and interlacing patterns. This parameter change optimizes the signal characteristics to achieve lower PAPR and CM, enabling higher transmission power while complying with unlicensed spectrum regulations

Inventive Principle:
Principle #35Parameter changes

2Reliability

If transmission power is increased to improve signal quality, then signal quality improves, but regulatory requirements for maximum PSD and bandwidth occupancy are violated

Engineering Contradiction:
Improvesignal qualityVSAvoidregulatory compliance
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

By segmenting the transmission into interlaced resource blocks across multiple subbands, the patent achieves frequency diversity and robust signal quality while distributing the power spectral density to meet regulatory masks. The interlacing ensures no single subband exceeds PSD limits while maintaining overall transmission quality

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs dynamic interlace pattern selection and clustered DFT-S-OFDM parameters that can be adapted to different channel conditions and regulatory requirements. This dynamic approach allows optimization of signal quality while continuously complying with PSD and bandwidth occupancy constraints

Inventive Principle:
Principle #15Dynamics

3Power

If interlacing techniques with clustered DFT-S-OFDM are used, then PAPR and CM are reduced allowing higher transmission power, but device complexity increases

Engineering Contradiction:
Improvetransmission powerVSAvoiddevice complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The interlacing technique segments resource blocks into structured patterns across subbands, which simplifies the complexity management by providing a regular, predictable structure. This segmentation enables efficient implementation of clustered DFT-S-OFDM with reduced computational overhead compared to unstructured approaches

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

By changing to clustered DFT-S-OFDM with specific cluster configurations and interlacing patterns, the patent reduces PAPR and CM values, which directly enables higher transmission power. The parameter optimization balances the increased processing requirements against the significant gain in transmission power efficiency

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3387778B1Interlace pattern selection for low cm/PAPR transmission
Publication Date: 2020.11.04 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP3387778B1 patent drawingFigure 1
  • EP3387778B1 patent drawingFigure 2
  • EP3387778B1 patent drawingFigure 3

AI summary

There is disclosed a network node (100) for a wireless communication network. The network node (100) is adapted for performing interlacing based on a time and/or frequency structure and/or resource structure.There are also disclosed related devices and methods.(Fig. 11)