HARQ Resource Allocation for Polar Code URLLC Retransmissions

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Solution Overview

Problem

Current wireless communication systems, particularly in ultra-reliable low latency communications (URLLC), face inefficiencies in retransmissions due to equal resource allocation for initial and retransmissions, which hinder the satisfaction of stringent latency and reliability requirements.

Innovation Solution

Implementing a method that allocates more resources for retransmissions than initial transmissions, incorporating incremental redundancy and Chase combination techniques for polar-coded communications, allowing for self-decodable retransmissions and improved HARQ performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If equal resources are allocated for initial transmission and retransmission, then resource allocation simplicity is maintained, but throughput and reliability are insufficient for URLLC requirements

Engineering Contradiction:
ImprovethroughputVSAvoidresource allocation complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements dynamic resource allocation where the resource allocation for retransmission is adjusted based on the outcome of the initial transmission. Specifically, the retransmission resource allocation is set to be greater than the initial transmission resource allocation when retransmission is needed, creating a dynamic adaptation mechanism that optimizes throughput while meeting URLLC reliability requirements

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the resource allocation parameter between initial transmission and retransmission. By setting the retransmission resource allocation parameter to be larger than the initial transmission parameter, the system achieves improved throughput and reliability without requiring complete redesign of the resource allocation framework

Inventive Principle:
Principle #35Parameter changes

2Reliability

If incremental redundancy and Chase combination are both used in retransmission, then reliability is improved, but processing complexity increases

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidHARQ processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the retransmission into two distinct components: incremental redundancy part and Chase combination part. This segmentation allows the receiver to process each component separately using appropriate decoding strategies, improving reliability while managing processing complexity through structured separation of functions

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent merges incremental redundancy and Chase combination techniques within the same HARQ retransmission framework. By combining these two complementary approaches, the system leverages the error correction capabilities of incremental redundancy and the diversity gain of Chase combination to achieve enhanced reliability for URLLC communications

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If more resources are allocated for retransmission than initial transmission, then URLLC reliability requirements are met, but resource efficiency for other users may deteriorate

Engineering Contradiction:
ImproveURLLC reliabilityVSAvoidoverall system throughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies partial excessive action by allocating more resources than the initial transmission only when retransmission is actually needed and only for the specific resources required to meet URLLC reliability targets. This avoids unnecessary resource waste while ensuring sufficient resources are available when needed for critical URLLC communications

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3714563B1Techniques and apparatuses for hybrid automatic repeat request design of polar codes for ultra-reliable low latency communications
Publication Date: 2023.07.12 QUALCOMM INC
  • EP3714563B1 patent drawingFigure 1
  • EP3714563B1 patent drawingFigure 2
  • EP3714563B1 patent drawingFigure 3

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless communication device may perform a first transmission of a communication that is encoded using a polar coding technique; and perform at least one retransmission of the communication, wherein more resources are allocated for the at least one retransmission than for the first transmission, and wherein the at least one retransmission includes an incremental redundancy version of the communication and a version of the communication for Chase combination. Numerous other aspects are provided.