PBCH Polar Coding with Progressive Interleaving and Scrambling

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Solution Overview

Problem

The existing PBCH encoding/decoding method in LTE systems is not suitable for 5G communications, as it faces challenges in channel quality variations and timing confusion during polar code transmission.

Innovation Solution

A polar code encoding mode is applied to the PBCH, incorporating progressive interleaving and scrambling to avoid timing confusion and improve decoding success, especially in poor channel conditions, by using a transformation matrix and scrambling vectors to generate multiple transmission versions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If progressive interleaving and scrambling are applied to polar code encoding, then decoding accuracy is improved and timing confusion is reduced, but device complexity increases

Engineering Contradiction:
Improvedecoding accuracyVSAvoidencoding complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The encoded sequence is divided into multiple segments through progressive interleaving, where each segment is scrambled independently using different scrambling vectors. This segmentation allows the receiver to process and decode segments separately, improving decoding accuracy through diversity while managing complexity through structured processing

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The interleaving and scrambling operations are performed in advance during encoding, creating multiple versions of the encoded sequence with different scrambling sequences. This preliminary action ensures that when transmission occurs, the receiver already has pre-processed sequences that can be directly decoded without complex real-time processing

Inventive Principle:
Principle #10Preliminary action

2Reliability

If multiple transmission versions are generated through scrambling, then reliability in poor channel conditions is improved, but loss of time increases due to additional processing

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidencoding time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

Different scrambling vectors are applied to create multiple transmission versions of the same encoded sequence. By changing only the scrambling parameter rather than re-encoding the entire sequence, the system generates diverse transmission versions quickly, improving reliability without excessive time penalty

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system generates multiple transmission versions periodically through systematic scrambling operations, where each version uses a different scrambling sequence. This periodic generation allows the receiver to combine multiple versions over time, improving reliability in poor channel conditions while maintaining efficient processing rhythm

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3614591B1Polar code transmission method and device
Publication Date: 2022.04.13 HUAWEI TECH CO LTD
  • EP3614591B1 patent drawingFigure 1
  • EP3614591B1 patent drawingFigure 2
  • EP3614591B1 patent drawingFigure 3

AI summary

A polar code transmission method and apparatus are provided, to apply a polar code encoding mode to a PBCH. The method includes: performing, by a transmit end, polar code encoding on some or all of to-be-encoded bit sequences U to generate an encoded sequence, where a length of U is N; and scrambling and interleaving, by the transmit end, the encoded sequence by using a scrambling sequence Sx and an interleaving matrix Px.