Correction Matrix for Implicit Beamforming in MIMO Systems

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Solution Overview

Problem

Implicit beamforming in wireless communication systems is impaired by radio frequency (RF) chain impairments such as gain/phase imbalances and coupling losses, which disrupt the reciprocity between forward and reverse channels, necessitating additional calibration exchanges and reducing the effectiveness of beamforming.

Innovation Solution

A method that determines a partial dimensional description of the reverse channel and develops a correction matrix based on both the reverse and forward channel descriptions to compensate for RF chain impairments, allowing for improved beamforming without the need for extensive calibration exchanges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If implicit beamforming is used in wireless communication systems, then beamforming effectiveness is improved, but RF chain impairments such as gain/phase imbalances and coupling losses disrupt channel reciprocity, requiring additional calibration exchanges

Engineering Contradiction:
Improvebeamforming effectivenessVSAvoidcalibration exchange requirements
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies partial action by determining only a partial dimensional description of the reverse channel rather than the full channel state information. This partial description is sufficient to calculate the correction matrix needed to compensate for RF chain impairments, reducing the calibration overhead while maintaining beamforming effectiveness.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent changes the parameter representation from full channel state information to a correction matrix derived from partial channel descriptions. This parameter transformation allows the system to compensate for RF chain impairments using fewer measurements, thereby reducing calibration exchange requirements while maintaining reliability.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If full dimensional description of reverse channel is determined, then accurate correction matrix can be developed, but calibration overhead and system complexity increase

Engineering Contradiction:
Improvechannel description accuracyVSAvoidcalibration exchange time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent uses partial action by determining only the necessary partial dimensional description of the reverse channel rather than the complete channel state. This partial description contains sufficient information to calculate the correction matrix, achieving the required measurement precision with reduced calibration time.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent extracts only the essential components needed for correction matrix calculation from the channel description process. By taking out only the necessary partial dimensional information rather than processing the full channel state, the system achieves accurate correction with minimal calibration overhead.

Inventive Principle:
Principle #2Taking out (Extraction)

3Manufacturing precision

If calibration exchanges are performed frequently to compensate for RF chain impairments, then beamforming accuracy is improved, but system productivity and throughput are reduced

Engineering Contradiction:
Improvebeamforming accuracyVSAvoidsystem throughput
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent applies partial action by using partial channel descriptions to calculate correction matrices, which maintains beamforming accuracy while significantly reducing the frequency and overhead of calibration exchanges, thereby preserving system throughput.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The patent transforms the calibration approach by changing from full channel state measurement to correction matrix calculation based on partial descriptions. This parameter change maintains beamforming precision while reducing calibration overhead, thus improving overall system productivity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2064818B1Calibration correction for implicit beamforming in a wireless MIMO communication system
Publication Date: 2017.07.26 MARVELL WORLD TRADE LTD
  • EP2064818B1 patent drawingFigure 1
  • EP2064818B1 patent drawingFigure 2
  • EP2064818B1 patent drawingFigure 3

AI summary

A transmitter beamforming technique for use in a MIMO wireless communication system determines a partial description of a reverse channel without determining a full dimensional description of the reverse channel. A correction matrix is developed from the partial description of the reverse channel and a description of the forward channel. The correction matrix is used to process signals to be transmitted via the forward channel, and a steering matrix is used to perform beamforming in the forward channel.