DFT-S-OFDM Pre-equalization for XR Power Reduction

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Solution Overview

Problem

The challenge in wireless communication systems is to reduce the processing requirements and power consumption at extended reality (XR) devices while maintaining effective data processing, which is limited by signaling between the XR device and the user equipment (UE).

Innovation Solution

The method involves generating a pre-equalized discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) waveform using minimum mean square error (MMSE) pre-equalization at the UE and transmitting it to a receiver device, thereby offloading complex decoding operations and reducing signaling overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If data processing is offloaded to a companion device (UE), then processing requirements and power consumption at the XR device are reduced, but signaling overhead increases

Engineering Contradiction:

Improvepower consumption at XR deviceVSAvoidsignaling overhead

Core Design Contradiction:

Use of energy by moving objectVSLoss of information

Solution Approach 1:

The patent applies pre-equalization to the DFT-S-OFDM waveform at the UE before transmission to the XR device. This preliminary processing of the signal compensates for channel effects in advance, reducing the need for complex equalization operations at the XR device while minimizing the information that needs to be signaled between devices.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If pre-equalization is applied to DFT-S-OFDM waveform, then communication performance is improved, but device complexity increases

Engineering Contradiction:

Improvecommunication performanceVSAvoidprocessing complexity at UE

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex equalization operations at the XR device with pre-equalization processing at the UE. By performing the equalization function at the transmitter side rather than the receiver side, the system achieves improved communication performance while distributing the computational complexity to the device with better processing capabilities.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS12244443B2Discrete Fourier transform spread orthogonal frequency division multiplexing waveform pre-equalization

Publication Date: 2025.03.04 QUALCOMM INC

AI summary

Various aspects of the present disclosure generally relate to wireless communication. Some aspects more specifically relate to discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) waveform pre-equalization for MIMO communications. A receiver device, such as an extended reality (XR) device, may be configured to offload a portion of data processing to a companion device, such as a user equipment (UE). In some aspects, the UE may generate a DFT-S-OFDM waveform and may apply a pre-equalization to the DFT-S-OFDM waveform. Applying the pre-equalization to the DFT-S-OFDM waveform may include applying a minimum mean square error (MMSE) pre-equalization to the DFT-S-OFDM waveform. The receiver device may receive the pre-equalized DFT-S-OFDM waveform from the UE and may process the pre-equalized DFT-S-OFDM waveform. For example, the receiver device may decode the pre-equalized DFT-S-OFDM waveform without performing fast Fourier transform (FFT) or inverse discrete Fourier transform (IDFT) operations.