LDPC Convolutional Encoding for Variable-Length Data Efficiency
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Solution Overview
Problem
Current LDPC codes face challenges in efficiently encoding variable-length data, leading to increased redundant bits and decreased data transmission efficiency, particularly in systems like Ethernet, where the fixed-length block code approach results in changes in coding rate and redundant sequence transmission.
Innovation Solution
The development of an LDPC-CC encoding method that utilizes a smaller protograph size and modifies the parity check matrix by adding '1' to approximate lower or upper triangular matrices, enhancing the order of the parity check polynomial to improve received quality and reduce redundant bits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed-length LDPC code block is used to encode variable-length data, then error correction capability is improved, but redundant bits increase and data transmission efficiency decreases
Solution Approach 1:
The patent applies dynamics by making the code block length variable rather than fixed. The encoding method dynamically adjusts the code block length to match the actual data length, allowing the system to maintain high error correction capability while minimizing redundant bits for different data sizes. This is achieved through adaptive selection of code block lengths from a set of predefined lengths based on the input data characteristics.
2Adaptability or versatility
If padding processing is performed to adjust transmission information sequence length, then LDPC code block correspondence is improved, but coding rate changes and redundant sequence transmission increases
Solution Approach 1:
The patent applies preliminary action by pre-defining multiple code block lengths that can accommodate various data sizes. Instead of performing padding processing during transmission, the system preliminarily selects an appropriate code block length from the predefined set that matches or closely fits the data length, thereby avoiding the need for padding and the associated redundant transmission.
3Loss of substance
If a smaller protograph size is used in LDPC-CC design, then redundant bits are reduced, but received quality may deteriorate
Solution Approach 1:
The patent applies parameter changes by systematically varying the protograph size and associated encoding parameters to find the optimal balance between redundant bits and received quality. The method involves adjusting parameters such as code block length, protograph size, and encoding rate based on the specific transmission conditions and data characteristics, thereby achieving good received quality with minimized redundant bits.
Data Source
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AI summary
A low-density parity check convolution code (LDPC-CC) is made, and a signal sequence is sent after subjected to an error-correcting encodement using the low-density parity check convolution code. In this case, a low-density parity check code of a time-variant period (3g) is created by linear operations of first to 3g-th (letter g designates a positive integer) parity check polynomials and input data.