LDPC Convolutional Code Termination for Variable-Length Frames
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Solution Overview
Problem
Current LDPC-CC technologies face challenges in supporting multiple coding rates with low computational complexity while maintaining high data quality and minimizing the number of terminations required for decoding.
Innovation Solution
The proposed solution involves an LDPC-CC encoder and decoder configuration that determines the sequence length of a termination sequence based on the information length and coding rate, using a determining section to compute a parity sequence and a decoding section that performs belief propagation decoding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If LDPC-CC encoding is applied to variable-length Ethernet frames, then information sequences of arbitrary length can be encoded, but the coding rate changes and redundant sequence transmission occurs due to padding or puncturing
Solution Approach 1:
The patent applies dynamics by making the termination sequence length variable rather than fixed. The determining section dynamically calculates the required termination sequence length based on the actual information sequence length and coding rate, allowing the encoding structure to adapt to different frame sizes without requiring fixed-length padding that causes redundant transmission
Solution Approach 2:
The patent changes the parameter of termination sequence length from a fixed value to a dynamically determined value. By calculating the termination sequence length based on the information sequence length and coding rate, the system optimizes the encoding process to minimize redundant transmission while maintaining the ability to handle variable-length frames
2Adaptability or versatility
If multiple coding rates are supported using conventional LDPC-CC methods, then versatility improves, but computational complexity increases
Solution Approach 1:
The patent achieves universality by designing a single encoding framework that can handle multiple coding rates (1/2, 2/3, 3/4) through one determining section that calculates termination sequence lengths based on the selected coding rate. This multi-functional approach allows the same hardware or software implementation to support various coding rates without requiring separate encoding circuits for each rate, thereby maintaining low computational complexity while achieving high versatility
3Adaptability or versatility
If termination is performed in LDPC-CC decoding, then decoding of variable-length sequences is enabled, but error correction capability and transmission efficiency deteriorate
Solution Approach 1:
The patent applies preliminary action by determining and preparing the exact termination sequence length before decoding begins. The determining section calculates how many termination bits are needed based on the information sequence length and coding rate, allowing the decoder to prepare appropriate processing parameters in advance. This prevents the need for excessive or insufficient termination, thereby maintaining error correction capability while enabling variable-length sequence decoding
Data Source
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AI summary
Transmission information generation and information length detection section 620 generates or acquires transmission data and outputs an information sequence made up of transmission data to parity computing section 632. Furthermore, transmission information generation and information length detection section 620 detects the sequence length of transmission data, i.e. the information size. Furthermore, transmission information generation and information length detection section 620 adds a known information sequence made up of known information bits (e,g. "0") necessary to generate parity bits corresponding to the termination section length at the rearmost end of the information sequence. Termination length determining section 631 determines the termination sequence length according to the information size and the coding rate. Parity computing section 632 calculates parity corresponding to the information sequence and known information sequence using an LDPC convolutional code, LDPC-CC, and outputs the parity obtained to modulation section 640. Modulation section 640 applies modulation processing to the information sequence and parity (including the termination sequence). Communication apparatus 600 includes information of the information size in a symbol relating to the information size and thereby reports the information of the information size to the communication apparatus which is the communicating party.