Supplementary Uplink Band for Orphaned NR Spectrum

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In wireless communication systems, deploying New Radio (NR) on adjacent spectrum with LTE results in an 'orphaned' band lacking corresponding uplink frequencies due to out-of-band interference, making it impractical for communications that require both downlink and uplink transmissions.

Innovation Solution

Configuring a frequency-separated supplementary uplink band to operate in time division duplex mode, allowing user equipment to select an alternative uplink carrier when the downlink signal quality is low, thereby enabling uplink data transmissions on an otherwise unusable downlink band.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a guard band is inserted between TDD New Radio band and FDD LTE band to prevent out-of-band interference, then interference protection is improved, but the New Radio band becomes an orphaned band without corresponding uplink frequency

Engineering Contradiction:

Improveinterference protectionVSAvoiduplink capability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent introduces a frequency dimension solution by configuring a supplementary uplink band at a different frequency than the downlink band. Instead of trying to find an uplink frequency adjacent to the downlink (which would cause interference), the system uses a frequency-separated supplementary uplink band, transforming the problem from a spatial adjacency constraint to a frequency resource allocation problem.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent introduces a supplementary uplink band as an intermediary resource. This supplementary band acts as a mediator between the orphaned downlink band and the uplink communication requirement, allowing uplink transmissions to occur on a different frequency band while maintaining logical pairing with the downlink through network configuration and user equipment selection mechanisms.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If NR and LTE are deployed on adjacent carriers/bands, then spectrum utilization is improved, but out-of-band interference occurs requiring guard bands

Engineering Contradiction:

Improvespectrum utilizationVSAvoidout-of-band interference

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the uplink and downlink operations into different frequency bands. Instead of having contiguous NR uplink and downlink bands adjacent to LTE, the system segments the NR operations into a downlink band (adjacent to LTE) and a separate supplementary uplink band, allowing both spectrum efficiency and interference avoidance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by allowing different parts of the NR deployment to have different characteristics. The downlink band maintains adjacency to LTE for spectrum efficiency, while the uplink function is localized to a separate supplementary band with different frequency characteristics, optimizing each function for its specific requirements.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS11196532B2Supplementary uplink with LTE coexistence adjacent to frequency division duplex spectrum for radio networks

Publication Date: 2021.12.07 AT&T INTELLECTUAL PROPERTY I L P

AI summary

The described technology is generally directed towards using a frequency-separated band as a supplementary uplink band for a new radio downlink band that cannot operate as a time division duplex band and otherwise has no paired uplink band. The paired bands are separated in frequency, yet operate in the time division duplex mode. The supplementary uplink for New Radio facilitates coexistence with LTE in the frequency division duplex spectrum.