LDPC Transport Block Segmentation for Adaptive Code Block Encoding

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Solution Overview

Problem

Existing LDPC coding methods struggle with efficient segmentation and encoding of transport blocks, particularly in varying code rates and block sizes, leading to inefficiencies in wireless communication systems.

Innovation Solution

An apparatus and method that attach transport block-level CRC bits, select an LDPC base graph based on code rate and block size, segment the transport block into code blocks, pad zeros to the last block, attach code block-level CRC bits, and encode each segment using the selected LDPC base graph, optimizing the encoding process for improved efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the transport block is segmented into multiple code blocks for LDPC encoding, then the encoding efficiency is improved, but the device complexity increases due to multiple segmentation and encoding operations

Engineering Contradiction:

Improveencoding efficiencyVSAvoidsegmentation and encoding complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The transport block is divided into multiple code blocks of equal size, with each code block independently encoded using LDPC. This segmentation allows parallel processing and improves encoding efficiency while maintaining manageable complexity through standardized block structures.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent dynamically adjusts the number of code blocks and their sizes based on the transport block size and code rate. By changing these parameters adaptively, the system optimizes encoding efficiency for different transmission conditions while controlling complexity through defined relationships between parameters.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If zeros are padded to the last code block to achieve equal block sizes, then the encoding process is simplified, but the loss of substance increases due to added padding bits

Engineering Contradiction:

Improveencoding process simplicityVSAvoidpadding overhead

Core Design Contradiction:

Ease of manufactureVSLoss of substance

Solution Approach 1:

Zero padding is applied selectively only to the last code block when needed to achieve equal block sizes, rather than padding all blocks uniformly. This localized approach simplifies the encoding process by creating uniform block structures while minimizing the total amount of padding overhead.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20260012209A1Method and apparatus for low-density parity-check (LDPC) coding

Publication Date: 2026.01.08 INTERDIGITAL PATENT HOLDINGS INC

AI summary

An apparatus and method are described. The apparatus includes a transceiver and processor, which attach transport block (TB) level CRC bits to a TB, select an LDPC base graph (BG) based on a code rate (CR) and TB size of the TB including TB level CRC bits, determine a number of code blocks (CBs) to use for segmenting the TB including TB level CRC bits depending on the selected LDPC BG, determine a single CB size for each of the CBs based on the number of CBs, segment the TB including TB level CRC bits into the CBs based on the number of CBs and CB size, pad zeros to a last CB of the CBs in the segmented TB, attach CB level CRC bits to each CB in the segmented TB, encode each CB in the segmented TB using the selected LDPC base graph, and transmit the encoded CBs.