Sidelink DMRS Mapping for PSCCH and PSSCH Multiplexing

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Solution Overview

Problem

The configuration of demodulation reference signals (DMRS) for Physical Sidelink Control Channel (PSCCH) and Physical Sidelink Shared Channel (PSSCH) in NR V2X sidelink is not clearly defined, particularly in cases where PSCCH and PSSCH overlap in time or frequency resources.

Innovation Solution

A communication apparatus is configured to map a DMRS for the sidelink shared channel onto a symbol that also maps a DMRS for the sidelink control channel, allowing for frequency-division multiplexing of the two channels. This configuration ensures that the DMRS for PSSCH and PSCCH are shared and allocated in the same symbol, facilitating accurate channel estimation and carrier frequency offset correction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If PSCCH and PSSCH are frequency-division multiplexed with overlapping time resources, then resource utilization efficiency is improved, but channel estimation accuracy deteriorates due to DMRS configuration ambiguity

Engineering Contradiction:

Improveresource utilization efficiencyVSAvoidchannel estimation accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent merges the DMRS resources for PSCCH and PSSCH by mapping both demodulation reference signals onto the same time-frequency resources. This combining approach allows the DMRS of PSSCH to be transmitted in the same symbol as the DMRS of PSCCH, improving resource utilization while maintaining channel estimation capability through the combined reference signal structure

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent makes the DMRS configuration universal for both PSCCH and PSSCH channels. The same DMRS mapping rules and resource allocation principles are applied to both control channel and shared channel, allowing a single set of reference signals to serve multiple functions for both channels simultaneously

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Quantity of substance

If DMRS for PSSCH and PSCCH are mapped onto the same symbol, then resource overhead is reduced, but signal interference increases

Engineering Contradiction:

Improveresource overheadVSAvoidsignal interference

Core Design Contradiction:

Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by using different DMRS sequences or different cyclic shifts for PSCCH and PSSCH DMRS within the same time-frequency resources. This allows the reference signals to be locally differentiated, reducing mutual interference while maintaining the resource-efficient overlapping structure

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent introduces orthogonal covering codes or cyclic shifts as intermediary mechanisms that allow PSCCH and PSSCH DMRS to coexist in the same resources. These intermediaries enable the system to maintain resource efficiency while managing the inherent interference through orthogonal or near-orthogonal signal separation

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS12289268B2Communication apparatus and communication method

Publication Date: 2025.04.29 NTT DOCOMO INC

AI summary

A communication apparatus includes a control unit configured to, when a sidelink control channel and a sidelink shared channel are to be frequency-division multiplexed, map a demodulation reference signal for the sidelink shared channel onto a symbol onto which a demodulation reference signal for the sidelink control channel is mapped; and a transmitting unit configured to transmit the symbol onto which the demodulation reference signal for the sidelink control channel and the demodulation reference signal for the sidelink shared channel are mapped.