Network Node PAPR Adjustment via Signal Time Shifting

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Solution Overview

Problem

The transmission of multiple wake-up signals at the same time in wireless communication networks increases the peak-to-average power ratio (PAPR), potentially by up to 6 dB, leading to inefficiencies and higher power consumption.

Innovation Solution

A method and apparatus for adjusting PAPR in network nodes by performing time shifts or phase shifts on signals intended for transmission at different frequency locations, allowing for the manipulation of signals to reduce PAPR while maintaining the ability to transmit multiple signals simultaneously.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple wake-up signals are transmitted simultaneously at different frequency locations, then the system can improve coverage and reach more user equipment, but the peak-to-average power ratio (PAPR) increases by up to 6 dB

Engineering Contradiction:

Improvecoverage capabilityVSAvoidpower consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent applies parameter changes by modifying the time domain characteristics of signals through time-shifting operations. Specifically, different wake-up signal copies transmitted at different frequency locations are shifted in time relative to each other, which changes the temporal distribution of signal energy and thereby reduces the peak-to-average power ratio while maintaining simultaneous transmission capability across multiple frequencies

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements dynamics by making the time offsets between signal copies configurable and adjustable. The network node can dynamically select different time shift values based on transmission conditions, allowing the system to adaptively optimize PAPR reduction while maintaining the benefit of multi-frequency simultaneous transmission for improved coverage

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If multiple wake-up signals are transmitted simultaneously at different frequency locations, then the system can improve coverage, but the peak-to-average power ratio (PAPR) increases leading to clipping interference

Engineering Contradiction:

Improvecoverage capabilityVSAvoidclipping interference

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent reduces clipping interference by changing the time domain parameters of the transmitted signals. By applying time-shifting operations to different signal copies at different frequency locations, the peak power moments are distributed across different time instances, which prevents constructive addition of peaks and thereby reduces PAPR and associated clipping interference

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the potentially harmful simultaneous transmission of multiple signals into a beneficial approach by introducing controlled time offsets. This transforms what would be a harmful PAPR increase from coherent addition into a manageable parameter through time diversification, allowing the system to maintain multi-frequency transmission benefits while eliminating the harmful clipping effect

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Use of energy by moving object

If time shifts are applied to reduce PAPR, then the peak-to-average power ratio decreases, but the signal transmission becomes more complex

Engineering Contradiction:

Improvepower efficiencyVSAvoidsignal processing complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent manages signal processing complexity by implementing time-shifting operations that are computationally efficient. The time offsets can be selected from predefined values or calculated using simple algorithms, avoiding complex signal processing while achieving PAPR reduction. The operation primarily involves adding time offset values to signal copy transmission timing, which is a straightforward parameter adjustment

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent balances complexity by making the time shift parameters dynamically adjustable based on transmission conditions. The system can adaptively select optimal time offset values without requiring complex real-time processing, allowing flexibility in managing the trade-off between PAPR reduction effectiveness and processing complexity based on current network conditions

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS20230318897A1Adjusting PAPR in a network node

Publication Date: 2023.10.05 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

A method for adjusting peak-to-average power ratio in a network node when transmitting multiple signals at respective multiple frequency locations is disclosed. The method comprises determining (101) a first signal at a first frequency location being intended for transmission simultaneously as a second signal at a second frequency location, manipulating the first and/or second signals by performing (103) an operation on the first and/or second signals, wherein the operation comprises one or more of: a time shift in a time domain or a frequency domain, and Determining a phase shift in the time domain or the frequency domain, and transmitting (104) the first and signals second signals, as manipulated or non-manipulated, at the first and second frequency locations, respectively. Corresponding computer program product, network node, and wireless communication network are also disclosed.