LDPC Header Encoding With Puncturing for Low-Latency SC/OFDM

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Solution Overview

Problem

In communication systems employing LDPC codes, there is a challenge in achieving low bit error rates at high data rates due to latency constraints imposed by traditional concatenated codes, making them unsuitable for high-speed applications like 10Gbps Ethernet and wireless communications.

Innovation Solution

The proposed solution involves innovative methods for encoding header information using LDPC codes with selective puncturing and repetition techniques, allowing for flexible header bit sizes in both single carrier (SC) and orthogonal frequency division multiplexing (OFDM) signaling, which enables efficient error correction and reduced latency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional concatenated codes are used for error correction, then error correction capability is achieved, but latency increases making them unsuitable for high-speed applications

Engineering Contradiction:
Improveerror correction capabilityVSAvoidlatency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent changes the fundamental parameters of the coding scheme by adopting LDPC codes with specific rate-matching techniques (puncturing, shortening, repetition) that enable near-Shannon-limit performance with lower latency compared to traditional concatenated codes, making them suitable for 10Gbps Ethernet and wireless communications

Inventive Principle:
Principle #35Parameter changes

2Reliability

If LDPC codes with selective puncturing and repetition are used, then latency is reduced and error correction performance is improved, but encoding complexity increases

Engineering Contradiction:
Improvebit error rate performanceVSAvoidencoding complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the encoded bit sequence into multiple groups and applies different rate-matching operations (puncturing, shortening, repetition) to different segments. This segmentation approach manages encoding complexity by breaking down the overall encoding process into manageable parts while maintaining near-capacity error correction performance

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs dynamic rate-matching techniques where the encoding parameters (puncturing patterns, repetition factors) are adjusted based on channel conditions and data rate requirements. This dynamic adaptation allows the system to optimize between error correction performance and encoding complexity for different operating scenarios

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If header information is encoded with flexible bit sizes, then adaptability to different communication modes (SC and OFDM) is improved, but encoding process complexity increases

Engineering Contradiction:
Improveadaptability to SC and OFDM signalingVSAvoidheader encoding complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a universal LDPC encoding framework that can handle both single carrier (SC) and orthogonal frequency division multiplexing (OFDM) signaling modes through the same rate-matching techniques. The encoder is designed to accommodate variable header sizes and different modulation schemes, providing multi-functional capability while managing complexity through standardized procedures

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP2320574B1Header encoding for single carrier (SC) and/or orthogonal frequency division multiplexing (OFDM) using shortening, puncturing, and/or repetition
Publication Date: 2019.10.09 AVAGO TECHNOLOGIES GENERAL IP (SINGAPORE) PTE LTD
  • EP2320574B1 patent drawingFigure 1
  • EP2320574B1 patent drawingFigure 2
  • EP2320574B1 patent drawingFigure 3

AI summary

Header encoding for SC and/or OFDM signaling using shortening, puncturing, and/or repetition in accordance with encoding header information within a frame to be transmitted via a communication channel employs different respective puncturing patterns as applied to different portions thereof. For example, a first puncturing pattern is applied to a first portion of the frame, and a second puncturing pattern is applied to a second portion of the frame (the second portion may be a repeated version of the first portion). Shortening (e.g., by padding 0-valued bits thereto) may be made to header information bits before they undergo encoding (e.g., in an LDPC encoder). One or both of the information bits and parity/redundancy bits output from the encoder undergo selective puncturing. Moreover, one or both of the information bits and parity/redundancy bits output from the encoder may be repeated/spread before undergoing selective puncturing to generate a header.