Beamforming Redundancy Selection for Sidelobe Interference

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In wireless communication systems, beamforming techniques can lead to interference between sectors due to overlapping sidelobes and main lobes, degrading performance when sectors use the same frequency and employ beamforming, resulting in reduced coverage and link budget for affected devices.

Innovation Solution

Implementing Transmit Time Interval (TTI) bundling, where redundant transmissions with different error detection and correction information are sent in multiple consecutive intervals, to mitigate interference by increasing redundancy and improving link budget for devices experiencing interference from overlapping sidelobes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If beamforming is used to improve coverage and sensitivity in specific directions, then coverage and link budget are improved, but interference between sectors increases due to overlapping sidelobes and main lobes

Engineering Contradiction:

Improvecoverage and link budgetVSAvoidinterference between sectors

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system dynamically changes the TTI bundling parameter based on beamforming angle thresholds. When the beamforming angle exceeds a threshold indicating potential interference, TTI bundling is activated to increase redundancy and improve reliability. This parameter adaptation resolves the contradiction by adjusting transmission redundancy according to the interference risk level.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If TTI bundling is used to increase redundancy and improve coverage, then link budget and reliability are improved, but transmission time and resource usage increase

Engineering Contradiction:

Improvelink budget and coverageVSAvoidtransmission time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

Instead of applying TTI bundling universally, the system applies it partially only when beamforming angles exceed interference thresholds. This selective application provides sufficient redundancy only when needed, avoiding unnecessary time loss in low-interference scenarios while maintaining reliability when interference is present.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The system dynamically adjusts the TTI bundling configuration based on real-time beamforming angle measurements and interference conditions. This dynamic adaptation allows the system to optimize between reliability and time efficiency by activating redundancy mechanisms only when the radio environment requires it.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS9622242B1Beam forming based redundancy selection

Publication Date: 2017.04.11 SPRINT SPECTRUM LLC

AI summary

At certain beamforming angles (i.e., those greater than a threshold amount) a sidelobe of a beamforming pattern used by a first sector may be pointed at wireless devices being serviced by a second sector. This causes the interference experienced by the first sector to be increased due to the transmissions of the wireless devices being serviced by the second sector. To help mitigate the interference experienced by the first sector, when the access node determines it is using a beamforming angle that may be susceptible to interference from the second sector (e.g., beamforming angle greater than a threshold), the first sector selects an amount of TTI bundling to be used by a wireless device. By configuring a wireless device to use TTI bundling (i.e., increase redundancy), the link budget for the wireless device is improved thereby lessening the effects of the interference being received via the sidelobe.