Time-Varying LDPC-CC Encoding for Variable-Length Data
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Solution Overview
Problem
Current LDPC codes face challenges in adapting to variable-length communication systems, as they require padding or puncturing to match fixed-length code blocks, leading to changes in coding rate and redundant sequence transmission.
Innovation Solution
The development of a time-varying LDPC-CC encoding method using parity check polynomials with a coding rate of (n−1)/n, allowing for encoding and decoding of arbitrary-length information sequences with a prime time varying period greater than 3, utilizing specific parity check polynomial equations to generate parity bits efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LDPC block code is applied to variable-length communication systems, then error correction capability is improved, but coding rate changes or redundant sequences are transmitted due to padding or puncturing
Solution Approach 1:
The patent applies dynamics by transitioning from fixed-length LDPC block codes to variable-length LDPC convolutional codes. The encoder processes information sequences of arbitrary length by using a time-varying parity check matrix that adapts to the input length, eliminating the need for padding or puncturing operations while maintaining error correction capability.
Solution Approach 2:
The patent changes the parameter of code structure from block code to convolutional code, enabling the code length to vary with the information sequence length. The parity check matrix parameters (H(i)) change dynamically based on the processing step i, allowing the system to adapt to different input lengths without altering the coding rate or introducing redundancy.
2Adaptability or versatility
If padding or puncturing processing is applied to match fixed-length code blocks, then LDPC code can be used in variable-length systems, but coding rate is changed or redundant sequences are transmitted
Solution Approach 1:
The patent extracts and eliminates the unnecessary padding and puncturing operations from the encoding process. By using LDPC convolutional codes with arbitrary-length support, the system directly processes the original information sequence without adding redundant bits, thereby removing the source of information loss and redundant transmission.
3Ease of operation
If LDPC block code with fixed block length is used, then encoding and decoding are straightforward, but the code cannot efficiently handle arbitrary-length information sequences
Solution Approach 1:
The patent achieves universality by designing an LDPC convolutional encoder that can process information sequences of any length using the same basic encoding structure. The time-varying parity check matrix H(i) provides a unified approach that works for all input lengths, eliminating the need for different encoding schemes for different block sizes while maintaining operational simplicity.
Data Source
AI summary
An encoding method and encoder of a time-varying LDPC-CC with high error correction performance are provided. In an encoding method of performing low density parity check convolutional coding (LDPC-CC) of a time varying period of q using a parity check polynomial of a coding rate of (n−1)/n (where n is an integer equal to or greater than 2), the time varying period of q is a prime number greater than 3, the method receiving an information sequence as input and encoding the information sequence using Equation 1 as a g-th (g=0, 1, . . . , q−1) parity check polynomial to satisfy 0.