LDPC Rate Matching with Circular Buffer Bit Reordering

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Solution Overview

Problem

Current data processing methods for quasi-cyclic low-density parity-check codes (QC-LDPC) lack an effective solution for rate matching, which is essential for adjusting code rates to meet various system transmission requirements in wireless communications.

Innovation Solution

A data processing method and device that performs rate matching on sequences generated through LDPC encoding using a circular buffer, involving steps such as obtaining and encoding transport blocks, segmenting data blocks, and storing or truncating encoded bit sequences to achieve the desired code rate, with options for bit reordering and interleaving to optimize decoding performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If rate matching is performed on LDPC encoded sequences to adjust code rates for different transmission requirements, then adaptability to various system requirements is improved, but device complexity increases due to the need for circular buffer management and bit reordering operations

Engineering Contradiction:
Improvecode rate adaptabilityVSAvoidprocessing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The transport block is segmented into multiple code blocks, each of which is independently encoded and processed through the circular buffer. This segmentation allows the system to handle large data blocks in manageable units, enabling flexible rate matching while maintaining manageable processing complexity for each segment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The circular buffer structure enables dynamic rate matching by allowing the same encoded sequence to be read out at different rates depending on the required code rate. The buffer can store the entire encoded sequence and output bits at variable rates, providing adaptability without requiring multiple fixed-rate processing paths.

Inventive Principle:
Principle #15Dynamics

2Reliability

If bit reordering and interleaving are applied to optimize decoding performance, then decoding performance is improved, but processing time increases

Engineering Contradiction:
Improvedecoding performanceVSAvoidprocessing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

Bit reordering and interleaving operations are performed on the encoded sequences before they are stored in the circular buffer. By performing these operations in advance, the system optimizes decoding performance without adding processing steps during the critical transmission phase, as the reordering is completed during the encoding preparation stage.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If truncated encoding is used to match the number of information bits to a given length, then manufacturing precision of code length is improved, but loss of information increases due to zero-insertion and puncturing

Engineering Contradiction:
Improvecode length precisionVSAvoidinformation bit loss
Core Design Contradiction:
Manufacturing precisionVSLoss of information

Solution Approach 1:

The system changes the code rate parameter to match the required transmission length rather than truncating the information bits. By adjusting the code rate and using circular buffer-based rate matching, the system achieves the desired output length without inserting zeros or puncturing information bits, thereby maintaining information integrity while achieving precise code length control.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3573270B1Data processing method and device
Publication Date: 2024.01.24 HUAWEI TECH CO LTD
  • EP3573270B1 patent drawingFigure 1
  • EP3573270B1 patent drawingFigure 2
  • EP3573270B1 patent drawingFigure 3~4

AI summary

Embodiments of this application disclose a data processing method and a data processing device. The method includes: obtaining a first to-be-processed bit sequence, where the first to-be-processed bit sequence is a transport block or a code block generated by performing code block segmentation on a transport block; encoding the first to-be-processed bit sequence to obtain a first encoded bit sequence; storing all or at least some bits of the first encoded bit sequence into a circular buffer; and outputing a first output bit sequence from the bits stored in the circular buffer. According to the method and the device that are provided in this application, rate matching can be implemented for a sequence generated through LDPC encoding.