LDPC Transmitter Segmentation for Variable FEC Frame Encoding
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Solution Overview
Problem
Existing signal transmitters and receivers face challenges in efficiently segmenting and encoding information bits to meet the requirements of varying signal receiving schemes in digital broadcasting, particularly in high definition digital television and portable broadcasting, where the number of signaling bits can exceed the capacity of Low Density Parity Check (LDPC) information bits, leading to inefficiencies in error correction and transmission.
Innovation Solution
A transmitter is designed with a segmenter that divides information bits into blocks based on preset reference values, an outer encoder that generates parity bits, and an LDPC encoder that encodes these blocks and parity bits to form LDPC codewords, allowing for flexible segmentation and encoding to match the LDPC code rate and repetition conditions, thereby optimizing the number of FEC frames and ensuring efficient transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If information bits are segmented into blocks based on preset reference values, then the number of segmented bits can be controlled to be equal to or less than a specific number, but the device complexity increases due to multiple encoding stages (outer encoder and LDPC encoder)
Solution Approach 1:
The information bits are segmented into multiple blocks based on preset reference values (Kseg) that are determined according to the code rate and repetition conditions. This segmentation allows the transmitter to handle variable numbers of information bits by dividing them into manageable blocks that can be processed through the encoding stages, ensuring that each block meets the required size constraints for LDPC encoding.
Solution Approach 2:
The patent implements nested encoding where an outer encoder (such as a convolutional encoder or Reed-Solomon encoder) is applied first to generate outer parity bits, and then an LDPC encoder is applied to the resulting blocks to generate LDPC parity bits. This nested structure allows multiple encoding mechanisms to work together, providing enhanced error correction capability while managing the complexity through hierarchical organization.
2Reliability
If multiple encoding stages are implemented (outer encoder and LDPC encoder), then the reliability of transmission is improved through enhanced error correction, but the processing time and productivity are reduced
Solution Approach 1:
The outer encoding is performed as a preliminary action before LDPC encoding. By applying the outer encoder first to generate outer parity bits, the system prepares the data in advance with an additional layer of error protection. This preliminary encoding step allows the subsequent LDPC encoding to work on pre-processed blocks, potentially simplifying the overall decoding process at the receiver and improving reliability through layered error correction.
Solution Approach 2:
The system dynamically adjusts encoding parameters including the preset reference values (Kseg), code rate, and repetition conditions based on channel conditions and service requirements. By changing these parameters, the system can optimize the balance between reliability and processing speed, selecting appropriate encoding strength and block sizes to match the current transmission environment.
3Adaptability or versatility
If the preset reference values are determined based on code rate and repetition conditions, then the adaptability to different transmission scenarios is improved, but the complexity of parameter determination increases
Solution Approach 1:
The preset reference values (Kseg) are dynamically determined based on the code rate and repetition conditions. Rather than using fixed segmentation values, the system adjusts the reference values according to the specific encoding configuration being used. This dynamic adaptation allows the transmitter to optimize segmentation for different code rates (e.g., 1/2, 2/3, 3/4) and repetition scenarios, ensuring efficient use of available bandwidth and error correction capabilities.
Data Source
AI summary
A transmitter is provided. The transmitter includes: a segmenter configured to segment information bits into a plurality of blocks based on one of a plurality of preset reference values; an outer encoder configured to encode each of the plurality of blocks to generate first parity bits; and a Low Density Parity Check (LDPC) encoder configured to encode each of the plurality of blocks and the first parity bits to generate an LDPC codeword including second parity bits, wherein the one of the preset reference values is determined depending on at least one of a code rate used to encode each of the plurality of blocks and the first parity bits and whether to perform repetition of at least a part of the LDPC codeword in the LDPC codeword.