Polarization-Aware Precoding Matrix for Cross-Polarized Antennas

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Solution Overview

Problem

Existing codebooks for MIMO systems do not consider polarization performance of cross-polarized linear array antennas, leading to significant errors in channel information feedback and system performance degradation.

Innovation Solution

Incorporating phase shifts and amplitude differences among cross-polarized linear array antennas into the determination of precoding matrices to improve the accuracy of downlink channel information and enhance system performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If existing codebooks are used for MIMO systems, then feedback overhead is reduced, but polarization performance of cross-polarized linear array antennas is not considered leading to significant errors in channel information feedback

Engineering Contradiction:
Improvefeedback overheadVSAvoidchannel information feedback accuracy
Core Design Contradiction:
Loss of informationVSMeasurement precision

Solution Approach 1:

The patent modifies the codebook structure by incorporating polarization parameters (phase shifts and amplitude differences) specific to cross-polarized linear array antennas. This changes the parameters of the codebook from conventional MIMO codebooks to polarization-aware codebooks, enabling accurate representation of channel characteristics while maintaining limited feedback overhead through structured codebook design.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent segments the codebook into multiple subsets, where each subset corresponds to different polarization configurations. This segmentation allows the system to select appropriate codebook subsets based on the specific antenna configuration and channel conditions, improving feedback accuracy without requiring a single monolithic codebook to cover all scenarios.

Inventive Principle:
Principle #1Segmentation

2Device complexity

If conventional codebooks are used without polarization consideration, then codebook structure is simple, but system performance degrades due to inaccurate channel information

Engineering Contradiction:
Improvecodebook structureVSAvoidsystem performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent introduces polarization parameters (phase shifts and amplitude differences) into the codebook structure. By changing the parameters from simple complex numbers to structured matrices that incorporate polarization information, the codebook maintains manageable complexity while significantly improving system performance through accurate channel representation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent adds a polarization dimension to the conventional MIMO codebook structure. Instead of only considering spatial dimensions, the codebook now incorporates polarization characteristics as an additional dimension, allowing for more accurate modeling of cross-polarized linear array antenna behavior without overwhelming complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If polarization performance is considered in codebook determination, then downlink channel information accuracy is improved, but codebook determination complexity increases

Engineering Contradiction:
Improvedownlink channel information accuracyVSAvoidcodebook determination complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent performs preliminary actions by pre-calculating and pre-organizing codebook entries that incorporate polarization parameters. The codebook is structured in advance with entries corresponding to different polarization configurations, allowing the system to quickly select appropriate code words during operation without performing complex real-time calculations, thus reducing operational complexity while maintaining high accuracy.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2586136B1A method and device for obtaining precoding matrix
Publication Date: 2020.02.19 ALCATEL LUCENT SA
  • EP2586136B1 patent drawingFigure 1~2
  • EP2586136B1 patent drawingFigure 3~4
  • EP2586136B1 patent drawing

AI summary

The present invention provides a method and device for obtaining precoding matrix. A network apparatus comprises a plurality of groups of cross-polarized linear array antennas. The method comprises: obtaining first channel indicating information indicating a first code word; obtaining second channel indicating information indicating a second code word; determining the precoding matrix, according to the first channel indicating information and the second channel indicating information, the first code word and/or the second code word comprises phase shifts and/or amplitude differences among the plurality of groups of cross-polarized linear array antennas. Since the first code word and the second code word for determining the precoding matrix by the network apparatus comprise phase shifts and amplitude differences among cross-polarized linear array antennas, the phase shifts and amplitude differences among cross-polarized linear array antennas are considered when the network apparatus sends downlink data according to the precoding matrix, so as to be able to improve the receiving quality of the sent data, thereby improving the system performance effectively.