Virtual Guard Bands for Base Station Interference Isolation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In wireless networks where backhaul and access radio interfaces are co-located and share the same radio band, it is challenging to isolate these interfaces to prevent cross-interference without using bulky, expensive, and power-hungry filters and amplifiers.

Innovation Solution

The implementation of virtual guard bands, which utilize inter-cell interference coordination techniques, such as X2 communications between base stations, to dynamically identify and reserve radio frequency resources that cause less interference, thereby reducing adjacent band interference without the need for hardware filters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hardware filters and amplifiers are used to isolate backhaul and access radio interfaces, then cross-interference between interfaces is prevented, but the system becomes bulky, expensive, and power-hungry

Engineering Contradiction:

Improveinterference isolationVSAvoidhardware complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces physical hardware filters with a software-based virtual guard band mechanism implemented through a radio resource scheduler. The scheduler identifies and reserves specific radio frequency resources that cause less interference between backhaul and access interfaces, eliminating the need for bulky hardware filters and amplifiers while maintaining interference isolation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the operational parameters of radio frequency resources by identifying specific frequencies or resource blocks that cause minimal interference between interfaces. The radio resource scheduler dynamically adjusts resource allocation parameters, reserving certain time-frequency resources as virtual guard bands to prevent cross-interference without requiring hardware modifications.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If traditional guard bands are used to separate frequency ranges, then interference between bands is prevented, but expensive filters are required to ensure frequencies are not used

Engineering Contradiction:

Improveinterference preventionVSAvoidfilter cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent substitutes expensive hardware filters with a software-based virtual guard band implementation. The radio resource scheduler enforces frequency separation through logical resource reservation rather than physical filtering, significantly reducing manufacturing costs while maintaining interference prevention capabilities.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a virtual representation of guard band functionality through software scheduling rules rather than physical filters. The radio resource scheduler copies the essential function of hardware filters by identifying and protecting specific frequency resources through coordination messages exchanged between base stations.

Inventive Principle:

Principle #26Copying

3Reliability

If rigorous filtering is applied to LTE guard bands, then interference sensitivity is addressed, but high-performance and expensive filters are required

Engineering Contradiction:

Improveinterference resistanceVSAvoidfilter performance cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces rigorous hardware filtering with a software-based approach where the radio resource scheduler identifies and reserves specific radio frequency resources that cause less interference. This virtual guard band mechanism provides interference resistance without requiring high-performance expensive filters.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent performs preliminary identification of interfering frequency resources through coordination messages between base stations before actual transmission occurs. The radio resource scheduler proactively reserves resources that cause minimal interference, preventing interference issues before they arise rather than requiring expensive filters to mitigate them.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11172396B2Virtual guard bands

Publication Date: 2021.11.09 PARALLEL WIRELESS INC

AI summary

A radio resource scheduler at a first base station may be configured to: identify radio frequency resources in use by the first base station, identify radio frequency resources to be reserved as virtual guard bands to reduce adjacent band interference, and install virtual guard band rules for reducing interference with adjacent bands. The virtual guard band information may be hints, allocations, priorities, reservations, or scheduling instructions for avoiding certain radio resources, radio resource blocks, or frequencies.