DMRS Port Indication for 8-Layer MIMO With Lower Bit Overhead

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Solution Overview

Problem

The existing DMRS port indication methods in wireless communication systems face high bit overhead when maximizing 8 layers of transmission, particularly in 3D MIMO technology, due to the need for additional bits to indicate punctured and unpunctured PDSCH states and layer information.

Innovation Solution

A DMRS port indication method and device that allocates specified ports based on a DMRS port indication table, using 4 bits to include a control bit for PDSCH puncture status and 3 bits for layer information, reducing overhead by classifying transmission states and supporting up to 8 layers with efficient port allocation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional DMRS port indication methods are used to support 8 layers of transmission, then the system capacity and transmission quality are improved, but the bit overhead for DMRS port indication information increases

Engineering Contradiction:
Improvesystem capacityVSAvoidbit overhead
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent segments the DMRS port indication into two parts: a common DMRS port indication applicable to all UEs, and a UE-specific DMRS port indication. This segmentation allows the system to support 8 layers while reducing individual overhead by sharing common information across multiple UEs.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent merges the common DMRS port indication with the physical downlink control channel (PDCCH) or physical downlink shared channel (PDSCH) transmission, combining multiple functions into a single transmission structure to reduce overall signaling overhead.

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If additional bits are added to indicate PDSCH puncture status and layer information, then the transmission accuracy is improved, but the control information overhead increases

Engineering Contradiction:
Improvetransmission accuracyVSAvoidcontrol information overhead
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent applies local quality by providing detailed puncture status indication only where needed (for specific UEs or specific resource blocks), rather than uniformly across all transmissions. This allows accurate tracking of punctured resources without adding excessive overhead everywhere.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses dynamic indication methods where the puncture status and layer information are conveyed through flexible field structures that adapt to actual transmission conditions, allowing the system to maintain accuracy while minimizing overhead when puncturing does not occur.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If 3D MIMO technology is implemented to extend transmission layers, then the degrees of freedom and system performance are improved, but the complexity of DMRS port management increases

Engineering Contradiction:
Improvedegrees of freedomVSAvoidDMRS port management complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements universal DMRS port indication mechanisms that work across different MIMO configurations (both 2D and 3D MIMO). The same indication structure and processing logic handle various layer configurations, reducing the complexity of managing DMRS ports in 3D MIMO systems.

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

Data Source

PatentEP3273739B1Demodulation reference signal port indication method, device, and base station
Publication Date: 2025.11.12 CHINA MOBILE COMM GRP CO LTD
  • EP3273739B1 patent drawingFigure 1
  • EP3273739B1 patent drawingFigure 2
  • EP3273739B1 patent drawingFigure 3

AI summary

A Demodulation Reference Signal (DMRS) port indication method, device and a base station are disclosed. A provided DMRS port indication table covers all cases of transmission maximally supporting 8 layers, and 4 bits defined by DMRS port indication information may indicate all the cases in the DMRS port indication table in combination with single-codeword transmission and double-codeword transmission cases of a related standard, so that bit overhead of the DMRS port indication information may be reduced.