CSI-RS Interference Parameter Detection for MU-MIMO Modulation

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Solution Overview

Problem

Current MU-MIMO receivers face challenges in blind modulation order detection, leading to systematic errors and reduced throughput due to complex detection algorithms and increased computational complexity, especially in scenarios with co-scheduled UEs and varying SNR levels.

Innovation Solution

Configuring zero power (ZP) channel state information reference signals (CSI-RS) to puncture specific resource elements in the physical downlink shared channel, allowing target UEs to perform interference measurements and improve modulation order detection without interference from co-scheduled UEs, and signaling this configuration to support advanced receivers for enhanced interference parameter detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If blind modulation order detection algorithms are used in MU-MIMO receivers, then modulation order detection can be performed without prior information, but systematic errors occur and throughput is reduced due to complex detection algorithms and increased computational complexity

Engineering Contradiction:
Improvemodulation order detection accuracyVSAvoiddetection algorithm complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces CSI-RS resources as an intermediary carrier to transmit interference information from co-scheduled UEs. Instead of directly detecting modulation order from mixed signals, the target UE receives interference parameters through the mediator CSI-RS, which simplifies the detection process and reduces computational complexity while improving detection accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The network performs preliminary action by pre-configuring CSI-RS resources and pre-transmitting interference information before the target UE needs to detect modulation order. This advance preparation provides the target UE with interference parameters in advance, eliminating the need for complex blind detection algorithms and reducing computational burden.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If blind detection algorithms are used for interference parameter detection, then detection can be performed without assistance, but computational complexity increases significantly

Engineering Contradiction:
Improveautonomous detection capabilityVSAvoidcomputational energy consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

CSI-RS serves as a mediator that carries pre-processed interference information to the target UE. This eliminates the need for the target UE to perform computationally intensive blind detection algorithms, significantly reducing energy consumption while maintaining autonomous detection capability through the assistance provided by the intermediary.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If co-scheduled UEs transmit simultaneously on the same time-frequency resources, then resource utilization improves, but interference between UEs increases and detection accuracy deteriorates

Engineering Contradiction:
Improveresource utilization efficiencyVSAvoidinterference parameter detection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent segments the transmission resources by dedicating specific CSI-RS resources to carry interference information from co-scheduled UEs. This segmentation allows the target UE to separate and identify interference parameters from the mixed signal, improving detection accuracy while maintaining simultaneous transmission and high resource utilization.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4459880A1Method for interference parameter detection (such as modulation order detection) enhancement
Publication Date: 2024.11.06 NOKIA TECHNOLOGIES OY
  • EP4459880A1 patent drawingFigure 1A
  • EP4459880A1 patent drawingFigure 1B
  • EP4459880A1 patent drawingFigure 2

AI summary

A network element in a wireless network sends, to a target UE, configuration of CSI RSs for use in a time-frequency resource space of a PDSCH. The configuration informs the UE to use the CSI RSs for interference parameter detection of co-scheduled UE(s) in the PDSCH. The network element transmits, toward the target UE, the CSI RSs. A target UE in a wireless network receives, from a network element, configuration of CSI RSs for use in a time-frequency resource space of a physical downlink shared channel. The configuration informs the target UE to use the CSI RSs for interference parameter detection of co-scheduled UE(s) in the PDSCH. The target UE receives, from the network element, the CSI RSs. The target UE performs the interference parameter detection using the CSI RSs.