Polar Code Channel Interleaving Using PBR Matrix Permutation

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Solution Overview

Problem

Current channel interleaving methods for polar codes in wireless communications, particularly in higher order modulation and fading channels, do not adequately randomize data sequences, leading to insufficient error correction capabilities and interference resistance.

Innovation Solution

The proposed method involves permuting the matrix used for interleaving based on column and row sequence numbers using pruned bit reverse (PBR) mapping patterns, enhancing interleaving randomization and performance while simplifying implementation compared to random interleaving.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional interleaving methods are used for polar codes, then the implementation is simpler, but the data randomization is insufficient and error correction capability is weak

Engineering Contradiction:
Improveerror correction capabilityVSAvoidinterleaving method complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The interleaving process is segmented into multiple distinct operations: writing bits to matrix positions, permuting row indices using PBR mapping, permuting column indices using PBR mapping, and reading bits from permuted positions. This segmentation allows each operation to be optimized independently while achieving comprehensive randomization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies PBR mapping in both row and column dimensions of the interleaving matrix, transforming the data sequence through two-dimensional permutation. This dimensional approach significantly enhances randomization effectiveness compared to single-dimensional methods, while maintaining manageable complexity through systematic indexing.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If random interleaving is used to improve data randomization, then error correction capability increases, but implementation complexity increases significantly

Engineering Contradiction:
Improvedata randomizationVSAvoidimplementation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses PBR mapping functions that transform index parameters systematically rather than using random permutation. The PBR mapping changes the parameters in a deterministic yet highly effective manner, achieving randomization equivalent to or better than random methods while being computationally efficient and easier to implement.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If no interleaving is performed, then the implementation is simplest, but burst errors cannot be dispersed and error correction range is exceeded

Engineering Contradiction:
Improveimplementation simplicityVSAvoidburst error impact
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and addresses the burst error problem by specifically designing the PBR mapping to disperse consecutive bits into widely separated positions in the permuted sequence. This targeted approach removes the harmful concentration of errors while maintaining overall system simplicity.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3605850B1Channel interleaving method and apparatus
Publication Date: 2023.10.04 HUAWEI TECH CO LTD
  • EP3605850B1 patent drawingFigure 1~2
  • EP3605850B1 patent drawingFigure 3
  • EP3605850B1 patent drawingFigure 4

AI summary

The present invention discloses a channel interleaving method of a polar (Polar) code. The method includes: determining an M_r-row and M_c-column matrix used for interleaving, where column sequence numbers of the matrix are represented by: [0, 1, ..., ic, ..., M_c-1], where ic is greater than or equal to 0, and is less than or equal to M_c-1; and row sequence numbers of the matrix are represented by: [0, 1, ..., ir, ..., M_r-1], where ir is greater than or equal to 0, and is less than or equal to M_r-1; writing to-be-interleaved bits into the matrix; and permutating, based on permutation patterns of the column sequence numbers and/or permutation patterns of the row sequence numbers, the matrix into which the to-be-interleaved bits are written, where the permutation patterns of the column sequence numbers are represented by: [Pc(0), Pc(1), ..., Pc(ic), ..., Pc(M_c-1)], where Pc(ic) is obtained by performing pruned bit reverse (PBR, pruned bit reverse)-based mapping on the column sequence number ic; and the permutation patterns of the row sequence numbers are represented by: [Pr(0), Pr(1), ..., Pr(ir), ..., Pr(M_r-1)], where Pr(ir) is obtained by performing pruned bit reverse (PBR, pruned bit reverse)-based mapping on the row sequence number ir; and reading interleaved bits from the permutated matrix.