LDPC Transmitter Interleaving for Incremental Redundancy Decoding

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Solution Overview

Problem

Current digital broadcasting communication systems face challenges in enhancing reception performance due to errors caused by fading and thermal noise, particularly in wireless channels, where existing methods for error correction are inadequate.

Innovation Solution

A transmitter is designed to process and transmit signals using an incremental redundancy (IR) method, employing a low density parity check (LDPC) codeword with an encoder, interleaver, and constellation mapper, where parity bits are generated based on specific parity submatrices and cyclic-shifted column groups within a parity check matrix, enhancing error correction capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If incremental redundancy (IR) method is used to transmit additional encoded data, then reception success rate is improved, but transmission time and complexity increase

Engineering Contradiction:

Improvereception success rateVSAvoidtransmission time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The parity check matrix is segmented into multiple submatrices, allowing the encoded data to be divided into different redundancy versions. This enables the receiver to accumulate and decode data in stages, improving reception success rate without requiring complete retransmission, thus reducing overall transmission time.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple redundancy versions are pre-encoded and prepared in advance based on the segmented parity check matrix. When transmission begins, the transmitter can immediately switch to different pre-prepared redundancy versions based on channel conditions, avoiding the time delay of real-time encoding during retransmission.

Inventive Principle:

Principle #10Preliminary action

2Adaptability or versatility

If multiple parity submatrices are used to generate different redundancy versions, then adaptability is improved, but device complexity increases

Engineering Contradiction:

Improveredundancy version diversityVSAvoidencoder complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Different submatrices of the parity check matrix are designed with specific local structures and properties. Each submatrix generates redundancy versions with distinct characteristics suited for different channel conditions, providing adaptability without requiring a complete redesign of the entire encoding system.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The multiple submatrices are organized in a nested hierarchical structure where smaller submatrices are embedded within larger ones. This nested arrangement allows the encoder to efficiently generate multiple redundancy versions by selectively activating different levels of the hierarchy, reducing overall device complexity while maintaining redundancy version diversity.

Inventive Principle:

Principle #7Nested doll (Nesting)

Data Source

PatentUS10819467B2Transmitter and signal processing method thereof

Publication Date: 2020.10.27 SAMSUNG ELECTRONICS CO LTD

AI summary

A transmitter is provided, which includes: an encoder configured to generate a low density parity check (LDPC) codeword comprising information word bits, first parity bits and second parity bits based on a parity check matrix; an interleaver configured to interleave the LDPC codeword; and a constellation mapper configured to map the interleaved LDPC codeword on constellation points, wherein the first parity bits are generated based on one of parity submatrices constituting the parity check matrix and the second parity bits are generated based on another of the parity submatrices constituting the parity check matrix.