PDCCH Incremental Redundancy Combining for Reliable Control Decoding

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Solution Overview

Problem

Current encoding techniques for the Physical Downlink Control Channel (PDCCH) in wireless communications networks, particularly in 5G and LTE systems, face challenges in achieving optimal reliability and integrity when using repetition schemes, leading to performance degradation due to puncturing and lack of coding gain in certain scenarios.

Innovation Solution

The implementation of an incremental redundancy scheme for PDCCH repetition, which avoids puncturing bits by using different redundancy versions and dynamic switching between chase combining and incremental redundancy schemes, improves the reliability and integrity of control information transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If repetition schemes are used for PDCCH encoding, then reliability of control information is improved, but performance degradation occurs due to puncturing and lack of coding gain

Engineering Contradiction:
Improvereliability of control informationVSAvoidcoding gain
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The system dynamically switches between chase combining and incremental redundancy schemes based on channel conditions and reliability requirements. This dynamic adaptation allows the system to optimize coding gain while maintaining reliability, avoiding the performance degradation associated with static repetition schemes that use puncturing.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the encoding parameters by using different redundancy versions in incremental redundancy schemes. Instead of repeating the same encoded data with puncturing, the system varies the redundancy parameters to provide different coding gains, thereby improving overall reliability without information loss.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If higher aggregation levels are used to improve reliability, then block error rate performance improves, but resource usage increases

Engineering Contradiction:
Improveblock error rate performanceVSAvoidresource usage
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The system dynamically selects between chase combining and incremental redundancy schemes based on the required reliability level and available resources. This dynamic selection allows the system to achieve target block error rate performance with optimized resource usage, avoiding the need to always use higher aggregation levels which consume more resources.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes redundancy parameters and version numbers to optimize the trade-off between reliability and resource consumption. By adjusting these parameters dynamically, the system can achieve similar block error rate performance to higher aggregation levels while using fewer resources.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If chase combining is used for repeated transmission, then simplicity of implementation is maintained, but coding gain is limited

Engineering Contradiction:
Improvesimplicity of implementationVSAvoidcoding gain
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The system dynamically switches between chase combining and incremental redundancy schemes. When simplicity is prioritized, chase combining is used; when maximum reliability is needed, incremental redundancy with different redundancy versions provides enhanced coding gain. This dynamic approach allows the system to adapt to different operational requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention creates a universal encoding system that can perform both chase combining and incremental redundancy functions. This multi-functionality allows the system to maintain simplicity when needed while achieving higher coding gain when required, making the system adaptable to various reliability requirements without sacrificing ease of implementation.

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

Data Source

PatentEP3837786B1Infrastructure equipment, communications device and methods
Publication Date: 2022.11.23 SONY GROUP CORP
  • EP3837786B1 patent drawingFigure 1
  • EP3837786B1 patent drawingFigure 2
  • EP3837786B1 patent drawingFigure 3

AI summary

A communications device receive data from a wireless communications network by detecting from one or more control channels of a wireless access interface one or more encoded data units of a plurality of encoded data units into which an error correction encoded control information has been divided in accordance with an incremental redundancy scheme. The communications device decodes the error correction encoded control information by combining the one or more detected encoded data units in accordance with an arrangement of encoded bits of the error correction encoded control information in each of the plurality of encoded data units. Each of the plurality of encoded data units comprises a different set of the encoded bits according to a different redundancy version number of the incremental redundancy scheme. The combining the one or more detected encoded data units includes identifying each of the one or more encoded data units from physical resources on which the one or more encoded data units are detected to determine the redundancy version of each encoded data unit, identifying the arrangement of encoded bits of the error correction encoded control information in each of the one or more encoded data units based on the determined redundancy version, and combining the encoded bits from the one or more encoded data units in accordance with the incremental redundancy scheme. In one example, the control information is used to indicate resources of a shared channel of the wireless access interface via which downlink data is to be transmitted to the communications device. As a result an incremental redundancy scheme can be used to transmit control information which does not require explicit signalling to identify the encoded data units of each redundancy version number.