DMRS-Based Joint CSI Reporting for Multi-TRP 5G Systems

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Solution Overview

Problem

In wireless communication systems with multiple transmission points, the mismatch between estimated channel state information (CSI) and scheduled CSI leads to throughput loss due to the use of minimum or mean quality indicators, causing inefficiencies in communication parameter computation.

Innovation Solution

Computing CSI using scheduled physical downlink shared channel (PDSCH) and demodulation reference signals (DMRS) from multiple transmit-receive points, reducing the need for frequent reference signal-based reporting and improving channel quality estimation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If minimum or mean quality indicators are used for joint CSI computation, then scheduling can be performed with a single PDCCH, but throughput loss occurs due to mismatch between estimated CSI and scheduled CSI

Engineering Contradiction:

Improvescheduling complexityVSAvoidthroughput

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The patent changes the parameter used for joint CSI computation from simple minimum or mean quality indicators to a more accurate channel quality indicator that reflects the actual combined channel conditions. This parameter change resolves the mismatch between estimated CSI and scheduled CSI, thereby eliminating throughput loss while maintaining single PDCCH scheduling.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If reference signal-based CSI reporting is used frequently, then channel quality estimation accuracy is maintained, but signaling overhead increases

Engineering Contradiction:

Improvechannel quality estimation accuracyVSAvoidsignaling overhead

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The patent performs preliminary channel quality estimation using downlink data traffic and demodulation reference signals, making the estimation result available before scheduling decisions are needed. This preliminary action eliminates the need for frequent separate reference signal-based CSI reporting, thereby reducing signaling overhead while maintaining accurate channel quality estimation for scheduling.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11362793B2Determining channel state information in 5G or other next generation wireless communication systems with multiple transmission points

Publication Date: 2022.06.14 AT&T INTELLECTUAL PROPERTY I L P

AI summary

The described technology is generally directed towards using demodulation reference signal (DMRS)-based channel state information (CSI) reporting in a wireless communications network with multiple transmit-receive points (TRPs). A user equipment computes joint CSI based on received DMRS data, e.g., received with downlink data traffic from two TRPs, such as co-located or backhaul connected TRPs. The DMRS-based joint CSI is reported to the multiple TRPs for use in scheduling subsequent data traffic, which can increase data throughput, and can reduce the frequency of CSI-RS reporting, increasing overall efficiency. The network can activate and deactivate DMRS-based CSI reporting.