Coordinated Uplink MIMO for Inter-Cell Interference Mitigation

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Solution Overview

Problem

Conventional MIMO techniques do not effectively address inter-cell interference caused by uplink and downlink transmissions in neighboring cells, limiting the performance of wireless communication systems.

Innovation Solution

A method is introduced to coordinate uplink transmissions from multiple mobile units to a plurality of base stations using a control and data plane entity, which schedules signals based on channel state information and quality of service parameters, and estimates information bits using signals received from the base stations, thereby reducing mutual interference through coherent combination of signals across multiple base stations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional MIMO techniques are used with multiple antennas at a single base station, then spectral efficiency is improved through spatial multiplexing, but inter-cell interference from neighboring cells is not addressed

Engineering Contradiction:
Improvespectral efficiencyVSAvoidinter-cell interference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent merges multiple base stations into a coordinated MIMO system where signals from multiple base stations are combined coherently at the mobile station. This is achieved by establishing coordinated relationships between multiple base stations and mobile stations, allowing the system to treat multiple cells as a unified MIMO system that can exploit spatial diversity across cells while suppressing inter-cell interference through coordinated signal processing.

Inventive Principle:
Principle #5Merging (Combining)

2Productivity

If multiple base stations transmit concurrently to improve system capacity, then spectral efficiency increases, but mutual interference between base stations increases

Engineering Contradiction:
Improvesystem capacityVSAvoidmutual interference
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful inter-cell interference into a beneficial resource by using interference suppression techniques. The coordinated MIMO system processes signals from multiple base stations coherently, allowing the system to distinguish between desired signals and interference, thereby converting what would normally be harmful interference into useful signal energy that contributes to overall system capacity.

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

3Reliability

If fast macro diversity switching is implemented to select base stations with lowest path loss, then uplink communication is improved, but burst timing coordination becomes complex

Engineering Contradiction:
Improveuplink communicationVSAvoidtiming coordination
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent establishes coordinated relationships and pre-configures signal processing parameters between multiple base stations and mobile stations before actual communication occurs. This preliminary coordination of MIMO parameters and signal processing techniques eliminates the need for complex real-time timing adjustments during fast macro diversity switching, as the coordination framework is already in place to handle signal combination and interference suppression.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2335445B1An architecture to support network-wide multiple-in-multiple-out wireless communication over an uplink
Publication Date: 2019.11.06 NOKIA OF AMERICA CORP
  • EP2335445B1 patent drawingFigure 1A
  • EP2335445B1 patent drawingFigure 1B
  • EP2335445B1 patent drawingFigure 1C

AI summary

The present invention provides a method of coordinating the uplink transmissions from at least one mobile unit to a plurality of base stations. The method is implemented in a control and data plane entity and includes scheduling, at the control plane function, uplink signals for transmission from the mobile unit(s) to the plurality of base stations. The method also includes receiving, at the data plane function from the plurality of base stations, signals including scheduled uplink signals transmitted from the mobile unit(s) to the plurality of base stations. The method further includes estimating, at the data plane function, information bits transmitted in the scheduled uplink signals using the received signals and channel state information indicative of a plurality of wireless communication links between the mobile unit(s) and the plurality of base stations.