Multi-Access Point Calibration for Coherent Transmission

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Solution Overview

Problem

In CoMP systems, phase differences between uplink and downlink channels of different access points cause interference, preventing coherent transmission and reducing system performance.

Innovation Solution

A method and apparatus that calibrate multiple access points by receiving and calculating parameter differences, specifically phase, amplitude, or both, between uplink and downlink channels, using feedback from user equipment to ensure accurate alignment and coherent transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple access points perform coordinated transmission, then system capacity and reliability are improved, but phase differences between access points cause interference and reduce performance

Engineering Contradiction:
Improvesystem capacityVSAvoidtransmission reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent changes the parameter of phase alignment by calculating parameter differences between uplink and downlink channels and applying calibration to adjust the phase parameters of multiple access points, transforming the unaligned state into an aligned state to enable coherent transmission

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism where user equipment feeds back downlink channel parameters to the network side, which then calculates parameter differences and performs calibration, creating a closed-loop system that continuously optimizes the phase alignment of multiple access points

Inventive Principle:
Principle #23Feedback

2Reliability

If access points transmit data jointly, then transmission quality is improved, but parameter differences prevent coherent transmission and reduce system performance

Engineering Contradiction:
Improvetransmission qualityVSAvoidcalibration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent enables the system to perform self-calibration by automatically calculating parameter differences between uplink and downlink channels and adjusting the access points accordingly, eliminating the need for manual calibration and reducing operational complexity

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent creates a universal calibration method that can be applied to multiple access points simultaneously, where the calibration process serves multiple functions: measuring channel parameters, calculating differences, and adjusting phases, thereby simplifying the overall system complexity

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

3Productivity

If uplink and downlink parameter differences are not calibrated, then device operation is simple, but phase differences cause interference and reduce spectral efficiency

Engineering Contradiction:
Improvespectral efficiencyVSAvoidcalibration operation
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent implements automatic feedback-based calibration where user equipment feeds back channel parameters, enabling the system to automatically detect and correct phase differences without manual intervention, thus maintaining spectral efficiency while keeping operations simple

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces manual calibration mechanisms with electronic signal processing and mathematical calculations, using channel reciprocity principles to automatically determine and correct parameter differences, thereby improving spectral efficiency without increasing operational complexity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP2755435B1Multi-access point calibration method and device
Publication Date: 2018.02.28 ZTE CORP
  • EP2755435B1 patent drawingFigure 1
  • EP2755435B1 patent drawingFigure 2
  • EP2755435B1 patent drawing

AI summary

A method and apparatus for calibrating multiple access points are provided. The method includes: a cell receiving at least one parameter of at least one downlink channel fed back by a UE; according to the at least one parameter of the at least one downlink channel, calculating at least one parameter difference between at least one uplink channel and the at least one downlink channel; and according to the at least one parameter difference, calibrating multiple access points. The present invention can ensure desirable coherent transmission between access points so as to ensure system performance.