Single-carrier resource mapping for non-terrestrial networks

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Solution Overview

Problem

Current wireless communication technologies, such as LTE and NR, face challenges in efficiently managing power amplifier linearity and transmit power in non-terrestrial network deployments due to high peak-to-average power ratio (PAPR) of OFDM modulation, which limits the ability to maintain sufficient power over long distances.

Innovation Solution

Implementing single-carrier resource mapping between an OFDM resource structure and a single-carrier resource structure, allowing base stations to map resource elements to time-domain samples, thereby reducing PAPR and enabling higher transmit power while maintaining power amplifier linearity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If OFDM modulation is used in non-terrestrial network deployments, then spectral efficiency is improved, but peak-to-average power ratio increases causing power amplifier non-linearity

Engineering Contradiction:

Improvespectral efficiencyVSAvoidpower amplifier linearity

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent changes the modulation parameter from traditional OFDM to single-carrier modulation, fundamentally altering the signal structure to reduce PAPR while maintaining spectral efficiency through careful resource element mapping in the time domain

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces a mapping mechanism as an intermediary between frequency-domain resource allocation and time-domain transmission, transforming OFDM resource elements into single-carrier time-domain samples through inverse Fast Fourier Transform operations

Inventive Principle:

Principle #24Intermediary (Mediator)

2Length of moving object

If transmit power is increased to compensate for long distance transmission, then coverage distance is improved, but power amplifier linearity deteriorates due to high PAPR

Engineering Contradiction:

Improvetransmission distanceVSAvoidpower amplifier linearity

Core Design Contradiction:

Length of moving objectVSReliability

Solution Approach 1:

The patent changes the modulation scheme from high-PAPR OFDM to low-PAPR single-carrier modulation, enabling the power amplifier to operate in its linear region even at high transmit power levels required for non-terrestrial network coverage

Inventive Principle:

Principle #35Parameter changes

3Length of moving object

If larger batteries are used to provide sufficient power for long distance transmission, then transmission distance is improved, but device complexity and cost increase

Engineering Contradiction:

Improvetransmission distanceVSAvoidbattery size

Core Design Contradiction:

Length of moving objectVSDevice complexity

Solution Approach 1:

The patent changes the modulation parameter to reduce PAPR, which improves power amplifier efficiency and reduces the total power consumption for a given transmission distance, thereby reducing battery size requirements

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11522647B2Single-carrier resource mapping for non-terrestrial network deployments

Publication Date: 2022.12.06 QUALCOMM INC

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a base station (BS) may map a plurality of resource elements from an orthogonal frequency division multiplexing (OFDM) resource structure to respective time-domain samples of a plurality of time-domain samples included in a single-carrier resource structure. The BS may transmit the plurality of time-domain samples to a user equipment (UE). Numerous other aspects are provided.