Control Channel Precoding Matrix Selection From PMI Feedback

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Solution Overview

Problem

In machine type communication (MTC), the receiving end faces difficulty in determining the precoding matrix when using CRS and DMRS joint channel estimation due to the absence of PMI feedback, which hinders the performance enhancement of the MPDCCH.

Innovation Solution

The method involves determining the precoding matrix based on PMI feedback and precoding parameters, including time-domain thresholds, repetition numbers, aggregation levels, and resource sets, to ensure consistent precoding matrix usage across control channel subframes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If CRS and DMRS joint channel estimation is adopted to enhance MPDCCH performance, then channel estimation accuracy is improved, but the receiving end cannot determine the precoding matrix when PMI feedback is enabled

Engineering Contradiction:
Improvechannel estimation accuracyVSAvoidprecoding matrix information
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent utilizes PMI feedback from the receiving end to enable the transmitting end to determine the precoding matrix. The feedback mechanism allows the system to adaptively select and apply the correct precoding matrix, resolving the information loss problem while maintaining channel estimation accuracy through CRS and DMRS joint estimation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent pre-configures multiple precoding matrices in a codebook structure before transmission. The transmitting end selects the appropriate precoding matrix based on PMI feedback and applies it to the control channel, ensuring that the precoding matrix information is available and correctly applied without requiring real-time determination during the transmission process.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If PMI feedback is enabled to determine precoding matrix, then precoding matrix determination is improved, but the complexity of channel estimation and data demodulation increases

Engineering Contradiction:
Improveprecoding matrix determination accuracyVSAvoidchannel estimation and demodulation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the precoding matrix determination process into distinct phases: PMI feedback reception, precoding matrix selection from codebook, and application to control channel. This segmentation allows the system to manage complexity by handling precoding matrix determination separately from channel estimation and data demodulation, while maintaining accurate precoding matrix identification.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent designs the precoding matrix determination mechanism to serve multiple functions: it enables accurate channel estimation, facilitates data demodulation, and maintains compatibility with both PMI feedback enabled and disabled modes. The CRS and DMRS joint estimation approach works universally across different transmission scenarios, reducing overall system complexity.

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

Data Source

PatentEP3920430B1Method and device for determining precoding, method and device for detecting data, storage medium and electronic device
Publication Date: 2026.02.18 ZTE CORP
  • EP3920430B1 patent drawingFigure 1~2
  • EP3920430B1 patent drawingFigure 3~5
  • EP3920430B1 patent drawingFigure 6

AI summary

Provided are a method and device for determining precoding, a method and device for detecting data, a storage medium and an electronic device. The method for determining precoding includes: receiving, by a first communication node, a precoding matrix indicator (PMI) sent by a second communication node; and determining a precoding matrix used on a control channel according to the PMI and a precoding parameter; where the precoding parameter includes at least one of: a PMI delay, the number of repetitions of the control channel, an aggregation level of the control channel, a candidate resource of the control channel, a starting physical resource block (PRB) sequence number of the control channel, a repetition resource group of the control channel, or a PRB set of the control channel.