DMRS Signaling Protection Using CRC and Payload Scrambling

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Solution Overview

Problem

Existing wireless communication systems face challenges in reliably detecting demodulation reference signals (DMRS) due to susceptibility to detection errors, leading to processing latency and decoding failures.

Innovation Solution

The implementation of cyclic redundancy check (CRC) techniques and scrambling codes based on DMRS signaling information to enhance the reliability of DMRS detection and data payload decoding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If DMRS contains signaling information without protection mechanisms, then the DMRS can convey channel estimation and signaling information efficiently, but the receiving device experiences detection errors and processing latency

Engineering Contradiction:
ImproveDMRS detection reliabilityVSAvoidprocessing latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by computing CRC bits in advance based on both the data bits and reference signal bits before transmission. This pre-computed CRC protection mechanism allows the receiving device to quickly verify DMRS detection accuracy without extensive processing, thereby reducing detection errors and processing latency simultaneously

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback through the CRC verification mechanism where the receiving device uses the pre-computed CRC bits to verify the correctness of detected DMRS signaling information. This feedback loop enables immediate detection of errors and triggers appropriate retransmission or correction actions, improving reliability while maintaining efficient processing

Inventive Principle:
Principle #23Feedback

2Reliability

If DMRS signaling information is transmitted without error detection, then the transmission overhead is reduced, but the receiving device suffers from detection errors and decoding failures

Engineering Contradiction:
ImproveDMRS signaling detection accuracyVSAvoiderror detection mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the CRC protection mechanism with the existing DMRS structure by computing CRC bits that are functions of both data bits and reference signal bits. This unified approach integrates error detection into the DMRS framework without requiring separate complex error detection systems, thereby improving detection accuracy while controlling complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent applies universality by designing the CRC mechanism to serve multiple functions: it protects both data transmission and DMRS signaling information simultaneously. The same CRC computation and verification process handles both types of information, reducing the need for separate error detection mechanisms and simplifying the overall system complexity

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

Data Source

PatentEP3646495B1Providing protection for information delivered in demodulation reference signals (DMRS)
Publication Date: 2025.02.12 QUALCOMM INC
  • EP3646495B1 patent drawingFigure 1
  • EP3646495B1 patent drawingFigure 2
  • EP3646495B1 patent drawingFigure 3

AI summary

Methods, systems, and devices for wireless communication are described. A device—such as a base station or user equipment (UE)—may transmit a demodulation reference signal (DMRS) including signaling information in addition to channel estimation information. To improve reception of the DMRS signaling information, the transmitting device may employ data protection techniques to the signaling information and modify a data payload transmitted in the physical data channel associated with the DMRS. In one aspect, the transmitting device may modify cyclic redundancy check (CRC) bits in the payload to include verification for the signaling information. In another aspect, the transmitting device may determine a scrambling code based on the signaling information, and may scramble the payload based on the scrambling code.