Adaptive CRC Length Selection for 5G Control Channel Transmissions

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Solution Overview

Problem

Existing wireless communication systems face inefficiencies in managing cyclic redundancy check (CRC) lengths, particularly in 5G technologies, where using a fixed long CRC for all data channels leads to unnecessary overhead for less demanding traffic types, and current CRC lengths do not meet the ultra-high reliability requirements of 5G services.

Innovation Solution

Adaptive management of CRC lengths by indicating the appropriate CRC size based on traffic type and data packet size, using both explicit and implicit methods, allowing for variable CRC lengths in transmissions to optimize efficiency and meet reliability requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fixed long CRC is used for all data channels, then reliability is improved, but overhead increases

Engineering Contradiction:
ImprovereliabilityVSAvoidoverhead
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent implements dynamic CRC length selection where the CRC length is adjusted based on traffic type and data packet size. Different CRC lengths (e.g., 16-bit, 24-bit, 32-bit) are selected dynamically to match the reliability requirements of different service types, replacing the fixed long CRC approach with an adaptive mechanism that optimizes both reliability and overhead.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the CRC length parameter according to specific conditions (traffic type, packet size). By modifying this key parameter dynamically, the system achieves different reliability levels appropriate for different services while minimizing overhead for less demanding traffic, directly resolving the contradiction between fixed reliability and variable overhead requirements.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a fixed long CRC is used for all data channels, then reliability is improved, but resource utilization deteriorates

Engineering Contradiction:
ImprovereliabilityVSAvoidresource utilization
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system dynamically adapts CRC length to match actual reliability needs, preventing waste of resources on overly robust error checking for simple traffic types. This dynamic adjustment optimizes resource utilization by allocating appropriate CRC lengths based on real-time requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

By changing the CRC length parameter based on traffic characteristics, the system improves resource utilization efficiency. Shorter CRCs are used for traffic types that don't require high reliability, freeing up resources while maintaining adequate error protection where needed.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If current CRC lengths are used, then compatibility is maintained, but reliability for 5G services deteriorates

Engineering Contradiction:
ImprovecompatibilityVSAvoidreliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces dynamic CRC length selection that can adapt to 5G service requirements while maintaining backward compatibility. The system can choose from multiple CRC length options including extended lengths (e.g., 48-bit, 64-bit) for ultra-reliable low-latency communications, while still supporting traditional lengths for legacy services.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system modifies the CRC length parameter to meet 5G reliability targets (e.g., 99.999% reliability for URLLC services). By implementing configurable CRC lengths, the system achieves the higher reliability required for 5G applications while preserving compatibility with existing systems through support for traditional CRC lengths.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4730680A2Cyclic redundancy check length management
Publication Date: 2026.04.22 QUALCOMM INC
  • EP4730680A2 patent drawingFigure 1
  • EP4730680A2 patent drawingFigure 2
  • EP4730680A2 patent drawingFigure 3

AI summary

A method and an apparatus for wireless communications is described. The method comprising determining a cyclic redundancy check, CRC, length for a transmission on a control channel, wherein when an allocation in a received physical downlink control channel, PDCCH, indicates that a parameter of the transmission is greater than or equal to a threshold, the CRC length is determined to be a first CRC length and when the allocation in the received PDCCH indicates that the parameter of the transmission is less than the threshold, the CRC length is determined to be a second CRC length smaller than the first CRC length and using the determined CRC length for the communication of the transmission.