Single-Carrier Waveform Mapping for Spur-Impacted Tones

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Solution Overview

Problem

Wireless communications systems face challenges due to receive or transmit chain imperfections that cause spurs, which degrade the reception of modulated symbols, particularly in single-carrier waveforms, leading to increased error vector magnitude and reduced throughput.

Innovation Solution

Techniques are employed to mitigate the impact of spurs by adjusting the mapping of frequency domain symbols to resource elements and generating waveforms that ensure low peak-to-average power ratio, enhancing error vector magnitude performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If transmit or receive chain imperfections are present, then spurs are generated, but error vector magnitude increases and performance degrades

Engineering Contradiction:

Improvereception qualityVSAvoidspurs

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes the harmful spurs from the frequency domain symbols by identifying their locations and excluding them from the inverse fast Fourier transform process, thereby eliminating the harmful factors while preserving the useful signal components

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent performs preliminary identification of spur locations in the frequency domain before generating the time domain waveform, allowing the system to pre-adjust the mapping of frequency domain symbols to resource elements and avoid placing data in spur-affected regions

Inventive Principle:

Principle #10Preliminary action

2Productivity

If conventional mapping is used, then resource elements are fully utilized, but spur impact degrades single-carrier waveform performance

Engineering Contradiction:

ImprovethroughputVSAvoiderror vector magnitude

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by treating different resource elements differently based on their susceptibility to spurs, adjusting the mapping of frequency domain symbols to resource elements specifically in regions affected by spurs while maintaining conventional mapping in clean regions, thereby locally optimizing performance without compromising overall throughput

Inventive Principle:

Principle #3Local quality

3Manufacturing precision

If spur mitigation techniques are applied, then error vector magnitude performance improves, but system complexity increases

Engineering Contradiction:

Improveerror vector magnitudeVSAvoidprocessing complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent uses copying by replicating frequency domain symbols onto alternative resource elements that are not affected by spurs, creating redundant copies of the data in clean frequency regions, which simplifies the mitigation process compared to more complex equalization or cancellation techniques

Inventive Principle:

Principle #26Copying

Data Source

PatentUS12609791B2Impacted tone mitigation solution for single carrier waveforms

Publication Date: 2026.04.21 QUALCOMM INC

AI summary

Certain aspects of the present disclosure provide techniques for a method for wireless communication at a wireless node comprising identifying at least one tone, obtaining a sequence of frequency domain symbols, adjusting a mapping of the frequency domain symbols to resource elements (REs) according to the at least one tone, generating a waveform based on the adjusted mapping, and outputting the waveform for transmission.