UE Frequency Offset Correction for Uplink Doppler Alignment

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Solution Overview

Problem

Existing wireless communication systems face challenges in accurately correcting frequency offsets, which can lead to signal interference and reduced communication quality, particularly in advanced technologies like 5G and New Radio (NR).

Innovation Solution

Implementing frequency offset correction techniques that involve applying and adjusting frequency offset corrections based on previous communications, allowing for improved alignment and reduction of interference in both downlink and uplink transmissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the same frequency offset correction is applied for both downlink and uplink communications, then the correction process is simplified, but the accuracy of frequency offset correction degrades in high-Doppler environments

Engineering Contradiction:

Improvecorrection process complexityVSAvoidfrequency offset correction accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies different frequency offset correction methods for downlink and uplink communications based on their specific characteristics. The downlink uses correction based on network node frequency offset measurements, while the uplink uses correction based on UE-measured Doppler shift, allowing each link to receive customized correction appropriate to its operational conditions and improving overall accuracy without excessive complexity

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent dynamically adjusts the frequency offset correction approach based on the communication direction and environmental conditions. The UE measures actual Doppler shift in real-time and uses this information to determine appropriate correction values for uplink transmissions, while relying on network-provided corrections for downlink, creating a adaptive correction system that responds to changing operational conditions

Inventive Principle:

Principle #15Dynamics

2Reliability

If frequency offset correction is performed for both downlink and uplink communications, then communication reliability improves, but computing and power resources are consumed

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidUE power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The UE performs frequency offset measurement and correction autonomously for uplink communications by measuring its own Doppler shift, eliminating the need for continuous complex processing. The UE uses simplified correction tables or pre-computed values rather than performing computationally intensive real-time calculations, thereby maintaining reliability while reducing power consumption

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent applies frequency offset correction selectively based on communication requirements. The UE applies full correction for uplink transmissions where Doppler shift is significant, while using simplified or no correction for downlink receptions where the network handles correction. This partial application of correction maintains necessary reliability while minimizing unnecessary computational overhead and power consumption

Inventive Principle:

Principle #16Partial or excessive action

3Measurement precision

If frequency offset indication is transmitted from network node to UE, then uplink correction accuracy improves, but signaling overhead increases

Engineering Contradiction:

Improveuplink frequency offset correction accuracyVSAvoidsignaling overhead

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The network node transmits frequency offset indication only when necessary, such as when Doppler shift exceeds a threshold or when correction is required for uplink communications. The indication provides only the essential correction information needed for uplink frequency alignment rather than continuous comprehensive signaling, thereby improving correction accuracy when needed while minimizing unnecessary signaling overhead

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The frequency offset indication is selectively provided based on the specific needs of uplink communications rather than being universally applied to all communications. The network determines when and where frequency offset correction is most critical and directs correction information accordingly, optimizing the balance between correction accuracy and signaling overhead for the specific operational context

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS12627542B2Frequency offset correction

Publication Date: 2026.05.12 QUALCOMM INC

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may transmit a first communication having a first frequency offset correction applied. The UE may receive an indication of a frequency offset of the first communication. The UE may transmit a second communication having a second frequency offset correction applied, the second frequency offset correction based at least in part on the first frequency offset correction and the frequency offset of the first communication. Numerous other aspects are described.