Prime-Period LDPC-CC Encoding for Variable-Length Frames
Find Innovative SolutionsGenerate Solutions
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 block codes, 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 polynomials to maintain high error correction capability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LDPC block codes are applied to variable-length communication systems, then error correction capability is improved, but padding or puncturing processing is required which changes coding rate and transmits redundant sequences
Solution Approach 1:
The patent applies dynamics by transitioning from fixed-length LDPC block codes to variable-length LDPC convolutional codes. The encoder dynamically adapts to input information of any length without requiring padding or puncturing, making the code length flexible rather than fixed. This resolves the contradiction by maintaining error correction capability while eliminating the need for redundant processing.
Solution Approach 2:
The patent changes the fundamental parameter of code length from fixed to variable. By using LDPC convolutional codes with arbitrary-length information sequences as input, the system maintains the error correction properties of LDPC codes while allowing the code length to adapt to the information length, thereby avoiding padding and puncturing operations.
2Productivity
If fixed-length LDPC code blocks are used, then encoding and decoding can be performed efficiently, but adaptability to variable-length communication frames is reduced
Solution Approach 1:
The patent achieves universality by designing an LDPC convolutional encoder that can handle information sequences of any length. The encoder structure with shift registers and mod 2 adders provides a unified solution that works for both fixed and variable-length inputs, making the system adaptable to different frame sizes without requiring separate processing paths.
Solution Approach 2:
The patent applies dynamics by making the code length adaptable to the information length. The LDPC convolutional code structure allows the encoded output length to dynamically match the input information length, providing flexibility for variable-length communication frames while maintaining encoding efficiency through the systematic encoder design.
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.