Massive MIMO AP Synchronization via Contaminating UE Relay

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Massive MIMO systems face challenges in synchronization between neighboring cells, particularly in non-licensed frequency bands where backhaul synchronization is complicated, leading to pilot contamination and poor communication performance due to interference from UEs connected to different APs.

Innovation Solution

The solution involves introducing additional communication channels within data frames for APs to communicate directly or indirectly with contaminating UEs, allowing for synchronization without additional orthogonalization dimensions, enabling APs to detect and mitigate interference by establishing separate channels for synchronization messages and pilot transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If backhaul synchronization is used for AP synchronization, then synchronization between APs can be achieved, but it becomes complicated in non-licensed frequency bands

Engineering Contradiction:
Improvesynchronization reliabilityVSAvoidsynchronization complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses contaminating UEs as intermediary nodes to establish direct communication channels between APs. Instead of relying on complex backhaul synchronization, the system leverages the presence of UEs that are contaminating the pilot signals to create a direct AP-AP communication path, simplifying the synchronization mechanism while maintaining reliability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the harmful effect of UE contamination (which causes interference and synchronization issues) into a beneficial resource. By establishing direct communication channels through these contaminating UEs, the system transforms the problem of pilot contamination into a solution for simplified AP synchronization, eliminating the need for complex backhaul procedures

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

2Object-affected harmful factors

If additional orthogonalization dimensions are introduced for synchronization, then interference mitigation can be improved, but system complexity and resource overhead increase

Engineering Contradiction:
Improveinterference levelVSAvoidsystem complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent extracts the synchronization function from the complex backhaul infrastructure and implements it directly through AP-AP communication channels established via contaminating UEs. This separation allows the system to mitigate interference without requiring additional orthogonalization dimensions across the entire system, reducing overall complexity while maintaining interference mitigation effectiveness

Inventive Principle:
Principle #2Taking out (Extraction)

3Productivity

If direct AP to AP communication channels are established, then synchronization efficiency is improved, but additional communication resources are required

Engineering Contradiction:
Improvesynchronization efficiencyVSAvoidcommunication resources
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent makes the contaminating UEs serve multiple functions: they continue to provide their primary communication service while simultaneously acting as relay nodes for direct AP-AP synchronization channels. This multi-functionality allows the system to establish efficient direct communication between APs without requiring dedicated additional resources, as the existing UE resources are utilized for dual purposes

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3158662B1Massive MIMO cell synchronization: AP to AP direct communication
Publication Date: 2021.06.09 SONY GROUP CORP
  • EP3158662B1 patent drawingFigure 1
  • EP3158662B1 patent drawingFigure 2
  • EP3158662B1 patent drawingFigure 3

AI summary

The invention is directed to synchronizing a massive multiple-input multiple- output (MIMO) link between an access point (AP) and a contaminating AP. An exemplary method comprises: detecting, by an AP (101), a contaminating AP (102), wherein the contaminating AP (102) interferes with communication between the AP (101) and other UEs (110, 120) in communication with the AP (101); and extracting, by the AP (101), broadcasted pilot information from a first channel associated with a data frame, wherein the broadcasted pilot information is associated with the contaminating AP (102).