Modulated Retro Reflector Feedback for Optical Wireless Systems

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Solution Overview

Problem

Existing wireless communication systems face challenges in reducing latency and power consumption when transmitting feedback in optical wireless communications (OWC) systems, especially in extended reality (XR) applications.

Innovation Solution

A wireless device equipped with a modulated retro reflector (MRR) sends feedback for received code blocks by modulating an optical beam and reflecting it back to the network entity, allowing feedback to be sent during the same time duration as receiving the code blocks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a wireless device uses a traditional optical beam transmitter to send feedback, then feedback can be transmitted, but power consumption increases and device complexity increases

Engineering Contradiction:

Improvepower consumptionVSAvoidfeedback transmission capability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The patent introduces a retroreflector as an intermediary component that enables the wireless device to transmit feedback without requiring an optical beam transmitter. The retroreflector receives optical beams from the network entity and reflects them back, allowing feedback transmission while eliminating the need for power-consuming transmission hardware at the wireless device.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The retroreflector serves multiple functions: it enables feedback transmission, reduces power consumption, and eliminates the need for complex transmission hardware. By making the feedback mechanism universal and compatible with existing optical beam infrastructure, the solution achieves reliability without increasing device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Loss of time

If feedback is sent during timing gaps between code blocks, then feedback transmission is possible, but latency increases

Engineering Contradiction:

ImprovelatencyVSAvoidfeedback transmission timing

Core Design Contradiction:

Loss of timeVSEase of operation

Solution Approach 1:

The patent enables continuous feedback transmission by allowing the wireless device to send feedback during the same time duration as code block reception. This eliminates idle timing gaps and maintains continuous useful action, thereby reducing latency while simplifying the timing operation.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The retroreflector is pre-configured to enable immediate feedback transmission upon receiving code blocks, eliminating the need to wait for timing gaps. This preliminary preparation of the feedback path allows for reduced latency without complicating the operational timing.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If an optical beam transmitter is included in the wireless device, then feedback transmission capability is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improvefeedback transmission capabilityVSAvoiddevice manufacturing

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extracts the optical beam transmission function from the wireless device and relocates it to the network entity. The wireless device only needs a passive retroreflector, which is much simpler to manufacture. This extraction resolves the contradiction by maintaining feedback capability while simplifying device manufacturing.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The retroreflector is a simple, inexpensive component compared to an optical beam transmitter. By using this cheaper component, the patent reduces manufacturing costs and device complexity while maintaining the essential feedback transmission capability through the network entity's transmission resources.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces latency and power consumption by eliminating the need for an optical beam transmitter in the wireless device and enabling simultaneous feedback transmission with code block reception.

Implementation Method 1

a modulated retro reflector (MRR) sends feedback for received code blocks by modulating an optical beam and reflecting it back to the network entity

Methodology Applied

Scientific EffectRetro reflection: Retroreflector

Data Source

PatentUS12334978B2Feedback mechanism for a laser based optical wireless communications system

Publication Date: 2025.06.17 QUALCOMM INC

AI summary

Methods, systems, and devices for wireless communications are described. The method may include a user equipment (UE) monitoring a set of time resources for a set of code blocks and receiving, from a network entity, a code block of the set of code blocks via an optical beam. Further, the method may include the UE modulating the optical beam based on receiving the code block and sending, to the network entity, the modulated optical beam including feedback associated with at least one code block of the set of code blocks.