Transparent MU-MIMO Transmission via DMRS Port Segmentation

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Solution Overview

Problem

Conventional LTE systems are limited to pairing only two pieces of UE on the same time-frequency resource, restricting system throughput and spectrum resource utilization due to limitations in DMRS ports and data streams.

Innovation Solution

A method and device for transparent MU-MIMO transmission that pairs at least two UE based on channel estimation matrices, configures DMRS and data power, and generates a beamforming weight to optimize signal transmission, allowing multiple layers of data streams to be sent simultaneously without altering existing protocols or signaling flows.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional LTE system protocols and DMRS port structures are used, then system compatibility and ease of operation are maintained, but the number of paired UE is limited to two, reducing system throughput and spectrum resource utilization

Engineering Contradiction:
Improvesystem throughputVSAvoidDMRS port structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the DMRS port structure into two independent parts: the original port structure that existing UE can identify, and the additional port structure that provides extra data streams. This segmentation allows the system to support more paired UE (beyond two) while maintaining compatibility with existing protocols and UE receivers, thereby increasing system throughput without requiring complex changes to the overall system architecture

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a nested structure where additional DMRS ports are embedded within the existing DMRS framework. The new ports are nested alongside the original ports, allowing the system to accommodate more data streams and paired UE while keeping the outer structure compatible with existing LTE protocols. This nested approach enables incremental enhancement without complete system redesign

Inventive Principle:
Principle #7Nested doll (Nesting)

2Quantity of substance

If the number of DMRS ports is increased to support more data streams, then more UE can be paired for MU-MIMO transmission, but the number of available data Resource Elements decreases, affecting signal quality

Engineering Contradiction:
Improvenumber of data streamsVSAvoidchannel estimation accuracy
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent applies partial action by selectively allocating DMRS ports - not all ports are used for channel estimation, but only the necessary subset. This allows the system to configure more DMRS ports than traditionally used, supporting more data streams and paired UE, while maintaining sufficient channel estimation accuracy by allocating adequate REs to the essential ports without requiring an increase in total RE allocation

Inventive Principle:
Principle #16Partial or excessive action

3Adaptability or versatility

If existing LTE transmission modes are used, then protocol compatibility is maintained, but only two pieces of UE can be paired with each identifying at most eight layers of data streams

Engineering Contradiction:
ImproveUE pairing flexibilityVSAvoidprotocol modification complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes the DMRS structure universal by designing it to serve multiple functions simultaneously: it maintains compatibility with existing LTE transmission modes for backward compatibility, while also supporting enhanced MU-MIMO configurations with more paired UE. The same DMRS structure serves both legacy UE and enhanced UE, providing multi-functionality without requiring separate protocol sets

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

Solution Approach 2:

The patent introduces dynamic configurability to the DMRS port allocation, allowing the system to adapt the number and configuration of ports based on the actual number of paired UE and channel conditions. This dynamic approach enables flexible UE pairing (beyond the fixed two-UE limit) while maintaining protocol compatibility, as the configuration can be adjusted through existing signaling mechanisms without requiring protocol modifications

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3128680B1Method and apparatus for implementing transparent multi-user multiple-input multiple-output transmission
Publication Date: 2018.08.01 ZTE CORP
  • EP3128680B1 patent drawingFigure 1~3
  • EP3128680B1 patent drawingFigure 4
  • EP3128680B1 patent drawingFigure 5

AI summary

Disclosed are a method and apparatus for implementing transparent multi-user multiple-input multiple-output (MU-MIMO) transmission. The method comprises: pairing at least two user equipments (UEs) according to channel estimation matrices of the UEs; configuring power of a demodulation reference signal (DMRS) of each paired UE, and configuring power of data (DATA) of each paired UE; and jointly generating a beamforming weight W according to the channel estimation matrix of each paired UE, and performing beamforming according to the power of the DMRS, the power of the DATA and the beamforming weight W, so as to generate a signal to be sent.