Polar Code Redundancy Generation for Wireless Fading Channels

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Solution Overview

Problem

Conventional polar code implementations are unsuitable for facilitating efficient communications between user equipment (UEs) and network entities, particularly in channel fading conditions, and suffer from high cyclic redundancy check (CRC) overhead and suboptimal performance in wireless communication networks.

Innovation Solution

The proposed solution involves generating redundancy versions of polar codes using a Hybrid Automatic Repeat Request (HARQ) scheme, where a UE determines the incorrect decoding of a second transmission and transmits subsequent transmissions based on combinations of coded bit sets from previous transmissions, optimizing the coded bit sets for improved channel diversity and reduced CRC overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional polar code implementations are used, then the communication system can operate with standard coding schemes, but the system suffers from high CRC overhead and suboptimal performance in channel fading conditions

Engineering Contradiction:
Improvecommunication performance under fading conditionsVSAvoidCRC overhead
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent segments the coded bit set into multiple groups and transmits different groups in different transmissions. Instead of transmitting the entire coded bit set in one go, the system divides it into manageable segments that can be selectively transmitted and combined, reducing the need for repeated full transmissions and thereby reducing CRC overhead while maintaining reliability under fading conditions

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic redundancy generation where the UE determines incorrect decoding and dynamically generates subsequent transmissions based on combinations of coded bit sets from previous transmissions. This adaptive approach optimizes the coded bit sets for improved channel diversity and reduces CRC overhead by only transmitting necessary redundancy information

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If standard HARQ schemes are used for polar codes, then retransmission can be performed, but the system lacks optimized redundancy generation for polar codes specific to fading channel conditions

Engineering Contradiction:
Improveredundancy generation adaptabilityVSAvoidperformance under fading conditions
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent changes the parameters of the coded bit sets dynamically based on channel conditions and decoding outcomes. When incorrect decoding is detected, the system generates subsequent transmissions with modified coded bit set combinations, adapting the redundancy generation to specific fading channel conditions rather than using fixed HARQ schemes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The UE performs self-service by determining incorrect decoding autonomously and generating its own subsequent transmissions based on combinations of previous coded bit sets. This self-adaptive mechanism allows the system to optimize redundancy generation for polar codes without requiring external control, improving adaptability to fading conditions

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3549295B1Techniques for redundancy generation of polar codes during wireless communications
Publication Date: 2024.08.28 QUALCOMM INC
  • EP3549295B1 patent drawingFigure 1
  • EP3549295B1 patent drawingFigure 2
  • EP3549295B1 patent drawingFigure 3

AI summary

Methods and apparatuses for wireless communications are described. In an aspect, a method and apparatus may include determining that a second transmission is decoded incorrectly in response to a first received indication on a communication channel. The method and apparatus may further include transmitting, on the communication channel, a third transmission and a fourth transmission based on a determination that the second transmission is decoded incorrectly, wherein the third transmission corresponds to a coded bit set of the third transmission including a first group of information bits of a coded bit set of a first transmission and a second group of information bits of a coded bit set of the second transmission and the fourth transmission corresponds to a coded bit set of the fourth transmission including a combination of the coded bit sets of the first transmission, the second transmission, and the third transmission.