LDPC Group-Wise Interleaving for Robust Bit-to-Symbol Mapping

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Solution Overview

Problem

Current digital broadcasting systems face challenges in providing high decoding and receiving performance for digital television and multimedia services, particularly in supporting various receiving methods and maintaining quality in a multi-channel, wideband environment.

Innovation Solution

A transmitting apparatus and interleaving method that maps bits from a low-density parity-check (LDPC) codeword onto modulation symbols, utilizing a specific configuration of parity check matrices and interleavers to enhance decoding and receiving performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional interleaving methods are used for LDPC codes in digital broadcasting, then device complexity is reduced, but decoding and receiving performance deteriorates

Engineering Contradiction:
Improvedecoding and receiving performanceVSAvoidinterleaving structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The interleaver is divided into multiple columns, with each column containing multiple bit groups. This segmentation allows for systematic organization of LDPC codeword bits while maintaining manageable complexity in the interleaving structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a two-dimensional interleaving structure with columns and rows, where bits are arranged in columns and groups of bits are arranged in rows. This dimensional approach enables improved decoding performance by creating specific bit distribution patterns across modulation symbols.

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

2Reliability

If standard mapping methods are used for LDPC codeword bits onto modulation symbols, then ease of operation is maintained, but decoding performance is suboptimal

Engineering Contradiction:
Improvedecoding performanceVSAvoidbit mapping complexity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The interleaver pre-arranges bits from the LDPC codeword into a specific two-dimensional pattern before modulation. This preliminary organization ensures that bits are optimally distributed across modulation symbols, improving decoding performance without adding complexity during the actual modulation process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Different columns and rows of the interleaver are designed with specific properties to optimize local bit distributions. This allows certain bit groups to be strategically positioned to enhance error correction performance in specific reception conditions.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3092764B1Bit interleaved coded modulation with a group-wise interleaver adapted to a rate 6/15 LDPC code of length 64800
Publication Date: 2022.05.25 SAMSUNG ELECTRONICS CO LTD
  • EP3092764B1 patent drawingFigure 1~2
  • EP3092764B1 patent drawingFigure 3~4
  • EP3092764B1 patent drawingFigure 5~6

AI summary

A transmitting apparatus is provided. The transmitting apparatus includes: an encoder configured to generate a low-density parity check (LDPC) codeword by LDPC encoding based on a parity check matrix; an interleaver configured to interleave the LDPC codeword; and a modulator configured to map the interleaved LDPC codeword onto a modulation symbol, wherein the modulator is further configured to map a bit included in a predetermined bit group from among a plurality of bit groups constituting the LDPC codeword onto a predetermined bit of the modulation symbol.