Interference Cancellation for Adjacent Cell Multicast

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Solution Overview

Problem

Wide-area multicast/broadcast networks in 3G and 4G LTE-Advanced wireless networks face challenges in managing interference across adjacent cells, particularly when multiple base stations transmit data packets over the same time-frequency physical resource blocks, leading to reduced spectral efficiency and the need for guard cells.

Innovation Solution

An apparatus and method that involve receiving radio transmission parameters and data packets from a set of base stations transmitting over shared time-frequency physical resource blocks, located in an adjacent cell. This apparatus uses the received data and parameters for interference cancellation, reconstructing the interfering signal and canceling it to improve uplink signal quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple base stations transmit data packets over the same time-frequency physical resource blocks in wide-area multicast/broadcast networks, then spectral efficiency is improved through frequency reuse, but interference between adjacent cells increases

Engineering Contradiction:

Improvespectral efficiencyVSAvoidinterference

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies interference cancellation technology to convert the harmful interference signal into a beneficial component. By receiving the interfering signal from base stations, reconstructing it, and subtracting it from the received signal, the system transforms the previously harmful interference into a cancelable component, enabling frequency reuse without the traditional interference penalties.

Inventive Principle:

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

Solution Approach 2:

The patent introduces an intermediary interference cancellation mechanism that mediates between the interfering base station signals and the victim base station. This intermediary process involves receiving, reconstructing, and subtracting the interfering signal, thereby enabling coherent frequency reuse while protecting against interference effects.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If guard cells are deployed to reduce interference in wide-area multicast/broadcast networks, then interference levels are reduced, but spectral efficiency decreases due to wasted resource blocks

Engineering Contradiction:

ImproveinterferenceVSAvoidspectral efficiency

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

Instead of using guard cells to passively block interference, the patent actively cancels interference through signal reconstruction and subtraction. This converts the harmful interference into a manageable signal component that can be removed, eliminating the need for guard cells and recovering spectral efficiency.

Inventive Principle:

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

Solution Approach 2:

The patent changes the approach from spatial parameter adjustment (guard cells) to signal processing parameter adjustment (interference cancellation coefficients). By dynamically adjusting the cancellation parameters based on received signals, the system achieves interference reduction without sacrificing spectral efficiency.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If interference cancellation is implemented using received data packets and radio transmission parameters, then uplink signal quality is improved, but device complexity increases

Engineering Contradiction:

Improveuplink signal qualityVSAvoidsignal processing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent performs preliminary actions by receiving and storing radio transmission parameters and data packets before the actual interference cancellation is needed. This preliminary collection of interference information enables the cancellation process to proceed efficiently when required, reducing real-time processing complexity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent creates a copy of the interfering signal by reconstructing it from received data packets and radio transmission parameters. This copied interference signal can then be subtracted from the original received signal without affecting the original signal integrity, simplifying the cancellation process.

Inventive Principle:

Principle #26Copying

Data Source

PatentUS12289751B2Apparatus, method and computer program for interference cancellation

Publication Date: 2025.04.29 NOKIA TECHNOLOGIES OY

AI summary

There is provided an apparatus including circuitry configured for performing: receiving radio transmission parameters for a set of base stations to transmit at least one data packet over same time-frequency physical resource blocks to the apparatus, the apparatus located in a first cell which is adjacent to a cell of at least one base station of the set of base stations; and receiving, in a data session, the at least one data packet at the apparatus; using the at least one data packet and the radio transmission parameters for interference cancellation for data signals received at the apparatus from user devices in the first cell.