Multiplexing CSI-RS and Synchronization Signals in 5G NR

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Solution Overview

Problem

Current wireless communication systems, particularly in new radio (NR) and 5G technologies, face challenges in efficiently multiplexing channel state information (CSI) reference signals (CSI-RSs) with synchronization signals, leading to potential collisions and interference, which affect the accuracy of channel state measurements and power control.

Innovation Solution

The method involves sampling subcarriers of a synchronization signal (SS) block based on the frequency density of CSI-RSs multiplexed in a symbol period and performing measurements or reporting of reference signal received power (RSRP) or CSI, using techniques such as puncturing of CSI-RS resources to avoid collisions with SS block signals, allowing for accurate channel state estimation and power determination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If CSI-RSs are multiplexed with SS blocks in the same symbol period, then resource utilization efficiency is improved, but measurement accuracy deteriorates due to potential collisions and interference

Engineering Contradiction:
Improveresource utilization efficiencyVSAvoidchannel state measurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent segments the frequency resources by sampling only specific subcarriers of the SS block that correspond to CSI-RS positions. This segmentation allows the UE to separate and process CSI-RS resources independently from other SS block signals, enabling accurate channel state measurements while maintaining efficient resource multiplexing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary processing step where the UE samples subcarriers of the SS block based on the frequency density of multiplexed CSI-RSs. This intermediary sampling mechanism acts as a mediator that enables coexistence of CSI-RS and SS block signals in the same resource period while maintaining measurement accuracy by focusing only on relevant subcarriers.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If CSI-RS resources are punctured to avoid collisions with SS block signals, then measurement accuracy is improved, but resource utilization efficiency deteriorates

Engineering Contradiction:
Improvechannel state measurement accuracyVSAvoidresource utilization efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent applies preliminary action by having the UE sample SS block subcarriers based on the known frequency density of CSI-RSs before performing measurements. This preliminary sampling identifies which subcarriers contain CSI-RS signals, allowing the UE to accurately measure channel state without needing to puncture resources, thereby maintaining both measurement accuracy and resource efficiency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system enables self-service by allowing the UE to autonomously determine which subcarriers to sample based on the configured CSI-RS frequency density. The UE automatically adjusts its measurement approach to focus on relevant subcarriers without requiring explicit resource puncturing commands, maintaining resource utilization while ensuring accurate measurements.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3673605B1Multiplexing channel state information reference signals and synchronization signals in new radio
Publication Date: 2022.07.20 QUALCOMM INC
  • EP3673605B1 patent drawingFigure 1
  • EP3673605B1 patent drawingFigure 2
  • EP3673605B1 patent drawingFigure 3

AI summary

Certain aspects of the present disclosure provide techniques for multiplexing channel state information (CSI) reference signals (CSI-RSs) and synchronization signals in wireless communications systems operating according to new radio (NR), e.g., 5th generation (5G), techniques. An exemplary method includes sampling subcarriers of a synchronization signal (SS) block based on a frequency density of channel state information (CSI) reference signals (CSI-RSs) multiplexed in a symbol period with the SS block, and performing at least one of: measuring at least one of reference signal received power (RSRP) or CSI, based on the sampled subcarriers and the CSI-RSs, or reporting at least one of the RSRP or the CSI, based on the sampled subcarriers and the CSI-RSs.