Multi-Cell Joint Detection for Handoff Interference Mitigation

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Solution Overview

Problem

In wireless communication systems, the handoff process between cells often results in service interruptions and degraded quality due to severe signal interferences at border areas, particularly in CDMA systems where multiple access interference and inter-symbol interference are prevalent, affecting both hard and soft handoffs.

Innovation Solution

A multi-cell joint detection process is implemented to analyze and mitigate interferences from multiple cells, enhancing decoding mechanisms by selectively grouping code channels and performing joint detection to improve communication quality during handoffs, allowing for both hard and soft handoffs with reduced noise interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional handoff procedures are used in CDMA systems, then base station switching can be performed, but severe signal interferences occur at border areas causing service interruptions and degraded quality

Engineering Contradiction:
Improvehandoff reliabilityVSAvoidsignal interference
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful signal interference from neighboring cells into a beneficial resource by using it as input for multi-cell joint detection. The interference signals are processed alongside the desired signal through interference cancellation techniques, transforming what was previously harmful into useful information for improving handoff reliability and reducing service interruptions at border areas.

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

2Speed

If hard handoff is performed to switch base stations, then new link establishment is faster, but service interruption occurs causing degraded quality of service

Engineering Contradiction:
Improvehandoff speedVSAvoidservice continuity
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent performs preliminary joint detection and interference cancellation operations before the handoff is completed. By pre-processing the signals from multiple cells and establishing detection mechanisms in advance, the system prepares the interference cancellation parameters and detection algorithms beforehand, enabling faster handoff execution without service interruption when the actual handoff occurs.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If soft handoff is performed to maintain service continuity, then service interruption is reduced, but communication quality deteriorates due to severe signal interferences

Engineering Contradiction:
Improveservice continuityVSAvoidinter-cell interference
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces multi-cell joint detection as an intermediary processing mechanism between the mobile terminal and multiple base stations. This intermediary system performs interference cancellation and signal combination, mediating the interaction between the terminal and interfering signals from neighboring cells. The joint detection process acts as a mediator that separates desired signals from interfering signals, maintaining service continuity while improving communication quality.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Device complexity

If conventional decoding mechanisms are used during handoff, then processing complexity is lower, but communication quality and throughput are reduced due to noise interference

Engineering Contradiction:
Improvedecoding complexityVSAvoidnoise interference
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent merges multiple decoding operations into a unified multi-cell joint detection framework. Instead of performing separate decoding for each cell independently, the system combines the detection and decoding processes across multiple cells simultaneously, sharing computational resources and interference cancellation results. This merging approach improves noise interference handling while maintaining reasonable processing complexity through resource sharing and coordinated processing.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP1891814B1Method for performing a handoff in a telecommunication system
Publication Date: 2021.03.03 SHANGHAI ULTIMATE POWER COMM TECH
  • EP1891814B1 patent drawingFigure 1
  • EP1891814B1 patent drawingFigure 2

AI summary

A method is disclosed for performing a handoff in a telecommunication system. The method comprises: Step I: performing a first multi-cell joint detection process for decoding for the communications within the home cell when a mobile terminal enters a handoff region between a home cell and one or more neighboring cells; Step II: performing a handoff process for a mobile terminal when in the home cell to join a target neighboring cell; and Step III: performing a second multi-cell joint detection process for decoding for the communications between the mobile terminal and the target neighboring cell. Therefore, the present invention can solve the problems in handoff of cells in telecommunication system, improve the decoding for the uplink or downlink communications, and enhance the throughout and performance of the telecommunication system.