LDPC Convolutional Encoding for Flexible Coding Rates
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Solution Overview
Problem
Current LDPC-CC encoders and decoders face challenges in supporting multiple coding rates with low computational complexity while maintaining high received data quality, as existing methods either increase computational complexity or compromise on data quality.
Innovation Solution
The proposed solution involves an LDPC-CC encoder and decoder configuration that uses a parity check polynomial to set coding rates, incorporating a coding rate setting section, computation sections, a parity computing section, and an adding section for encoding, and a log likelihood ratio setting section and computation processing section for decoding, utilizing belief propagation to achieve efficient encoding and decoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If puncturing processing is used to adjust coding rate in LDPC-BC, then coding rate flexibility is improved, but redundant sequence transmission and data quality deteriorate
Solution Approach 1:
The patent employs a time-varying periodic parity check matrix where the encoding pattern changes periodically over time. This dynamic structure allows the system to achieve different coding rates through natural periodic variation without requiring puncturing operations, thereby maintaining data quality while providing coding rate flexibility.
Solution Approach 2:
The patent changes the parameter of time-varying period in the parity check matrix to achieve different coding rates. By adjusting the period parameter and the structure of the parity check matrix at different time instances, the system can flexibly control the coding rate without introducing redundant transmissions or quality degradation.
2Adaptability or versatility
If multiple LDPC-CC codes are used to support multiple coding rates, then coding rate versatility is improved, but device complexity increases
Solution Approach 1:
The patent designs a universal LDPC-CC encoder with a time-varying periodic structure that can support multiple coding rates through a single unified framework. The encoder uses a general form of parity check matrix with period g, where different coding rates are achieved by configuring the matrix structure and period parameter, eliminating the need for multiple separate encoder implementations.
Solution Approach 2:
The patent segments the encoding process into periodic time-varying stages, where the parity check matrix structure repeats every g time instances. This segmentation allows the system to achieve multiple coding rates through temporal division rather than requiring multiple parallel encoder structures, thereby reducing overall device complexity.
3Adaptability or versatility
If LDPC-CC with time-varying period is used, then encoding flexibility is improved, but computational complexity increases
Solution Approach 1:
The patent implements periodic action by using a parity check matrix with time-varying period g, where the encoding pattern repeats periodically. This periodic structure provides encoding flexibility for different coding rates while maintaining computational efficiency through the regular, predictable pattern that can be pre-computed and stored, avoiding the need for complex real-time calculations.
Data Source
AI summary
An encoder and decoder using LDPC-CC (Low Density Parity Check-Convolutional Codes) is disclosed. In the encoder (200), an encoding rate setting unit (250) sets an encoding rate (s−1)/s (s=z), and an information creating unit (210) sets information including from information Xs,i to information Xz−1,i to zero. A first information computing unit (220-1) receives information X1,i at time point i to compute the X1(D) term of formula (1). A second information computing unit (220-2) receives information X2,i at time point i to compute the X2(D) term of formula (1). A third information computing unit (220-3) receives information X3,i at time point i to compute the X3(D) term of formula (1). A parity computing unit (230) receives parity Pi−1 at time point i−1 to compute the P(D) of formula (1). The exclusive OR of the results of the computation is obtained as parity Pi at time i. Ax.