Network-Assisted Time Reversal Precoding for RF Sensing

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Solution Overview

Problem

Current wireless communication systems face challenges in efficiently handling multipath propagation for RF sensing operations, which affects object detection and tracking performance, especially in environments with high signal-to-noise ratios and multiple bounces in the propagation path.

Innovation Solution

The method involves determining channel reciprocity information for sensing channels between nodes, generating time reversal precoding information based on this information, and providing it to the nodes to improve RF sensing operations. This includes using machine learning models to predict channel reciprocity and configure time reversal precoding accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If time reversal precoding is used to reduce multipath propagation impact, then object detection accuracy is improved, but channel reciprocity information requirements increase system complexity

Engineering Contradiction:
Improveobject detection accuracyVSAvoidchannel reciprocity information processing
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system performs preliminary channel reciprocity assessment before RF sensing operations. The network entity determines channel reciprocity information in advance and configures time reversal precoding accordingly, preparing the system to handle multipath propagation effects before they degrade detection accuracy.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The network entity acts as an intermediary that processes channel reciprocity information and generates time reversal precoding configurations. This intermediary processing relieves the complexity burden from individual sensing nodes by centralizing the channel analysis and precoding generation functions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If channel reciprocity prediction models are trained with multiple channel metrics, then sensing performance is improved, but training data requirements and processing time increase

Engineering Contradiction:
Improvesensing performanceVSAvoidmodel training time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system uses multiple channel metrics (channel estimates, signal-to-noise measurements, Doppler observations) to train the prediction model, providing more comprehensive training data than a single metric would offer. This partial use of available metrics improves model reliability without requiring all possible data types.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The channel reciprocity prediction model is trained in advance using collected channel metrics from multiple RF sensing signals. This preliminary training allows the model to be ready for deployment, reducing real-time processing requirements during actual sensing operations.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If time reversal precoding is configured based on machine learning predictions, then RF sensing accuracy is improved, but network entity processing complexity increases

Engineering Contradiction:
ImproveRF sensing accuracyVSAvoidnetwork entity processing
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The channel reciprocity prediction model operates autonomously, taking channel metrics as input and automatically generating predictions for time reversal precoding configuration. This self-service capability reduces the need for manual configuration and complex real-time processing at the network entity.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system uses feedback from multiple RF sensing signals and their corresponding channel metrics to continuously improve the prediction model. The network entity receives channel metric feedback and uses it to refine future precoding configurations, creating a closed-loop system that improves accuracy over time.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS20250080381A1Network assisted time reversal radio frequency sensing
Publication Date: 2025.03.06 QUALCOMM INC
  • US20250080381A1 patent drawing
  • US20250080381A1 patent drawing
  • US20250080381A1 patent drawing

AI summary

Techniques are provided for implementing time reversed reference signals for radio frequency (RF) sensing operations in a communication system. An example method for generating channel reciprocity information for radio frequency sensing operations includes receiving radio frequency sensing information from a sensing node, generating a channel reciprocity prediction based at least in part on the radio frequency sensing information and a channel reciprocity prediction model, and providing an indication for time reversal precoding to the sensing node based on the channel reciprocity prediction.