Non-Priority Transmitter Interference Alignment for Shared Spectrum

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Solution Overview

Problem

Wireless communication networks face interference issues due to shared spectrum usage among multiple users, leading to degraded performance, especially as demand for mobile broadband access increases and more devices access long-range and short-range networks, causing congestion and increased interference.

Innovation Solution

A method where a non-priority transmitter detects a priority reservation reference signal from a high-priority transmitter, generates channel estimates for both priority and non-priority receivers, and uses a transmission precoder to align data transmission and minimize interference with high-priority receivers, allowing for efficient sharing of the shared spectrum.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple users share the same spectrum resources, then spectrum utilization efficiency is improved, but interference between users increases

Engineering Contradiction:

Improvespectrum utilization efficiencyVSAvoidinterference between users

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the shared spectrum into priority-based channels, dividing users into high-priority and non-priority groups. This segmentation allows the system to manage interference by treating different user classes differently, enabling simultaneous transmission while controlling harmful effects through priority-based resource allocation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by assigning different transmission characteristics to different users based on their priority level. High-priority users receive transmissions with higher quality (less interference tolerance) while non-priority users accept lower quality (higher interference tolerance), allowing efficient spectrum sharing with differentiated service quality.

Inventive Principle:

Principle #3Local quality

2Productivity

If non-priority transmitters transmit on shared spectrum, then spectrum efficiency is improved, but interference with high-priority receivers increases

Engineering Contradiction:

Improvespectrum efficiencyVSAvoidinterference with high-priority receivers

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the potentially harmful interference from non-priority transmitters into a beneficial mechanism by using interference alignment. The non-priority transmitter deliberately directs its transmission to align interference in specific spatial directions, transforming the harmful interference into a controlled phenomenon that protects high-priority receivers while allowing non-priority transmissions to proceed.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the transmission parameters (precoder) of the non-priority transmitter based on channel state information to optimize the interference pattern. By adjusting the precoder, the system controls the spatial distribution of interference, allowing non-priority transmissions to coexist with high-priority receivers through parameter optimization rather than simple exclusion.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If transmission precoder is designed to minimize interference, then communication reliability is improved, but transmission complexity increases

Engineering Contradiction:

Improvecommunication reliabilityVSAvoidtransmission complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by having the non-priority transmitter obtain channel state information in advance before transmission. The transmitter estimates the channel response and calculates an appropriate precoder beforehand, based on detected reference signals from high-priority transmitters. This preliminary preparation enables interference-minimizing transmission without requiring complex real-time computation during the actual data transmission.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS10735121B2Unified spatial operation for dynamic medium sharing

Publication Date: 2020.08.04 QUALCOMM INC

AI summary

Unified spatial operations for dynamic medium sharing is disclosed in which a non-priority transmitter detects a priority reservation reference signal (RRS) over a shared spectrum from a high-priority transmitter The shared spectrum is shared by the non-priority transmitter with at least one high-priority communication pair. The high-priority communication pair includes a high-priority transmitter and the high-priority receiver. After detecting the RRS, the non-priority transmitter generates a non-priority channel estimate for a first channel between the non-priority transmitter and a non-priority receiver and a priority channel estimate for a second channel between the non-priority transmitter and the priority receiver. The non-priority transmitter transmits data on the shared spectrum using a transmission precoder determined using the non-priority channel estimate and the priority channel estimate, wherein the transmission precoder aligns transmission of the data to minimize interference with the high-priority receiver.