LDPC Transmitter Parity Scheduling for Puncturing and Diversity Gain
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Solution Overview
Problem
Current signal transmission methods for digital broadcasting lack efficiency in providing improved performance and coding gain, particularly in high-definition digital television and portable broadcasting scenarios, where existing methods fail to effectively utilize parity bits for enhanced reception and error correction.
Innovation Solution
A transmitter system incorporating a Low Density Parity Check (LDPC) encoder, repeater, puncturer, and additional parity generator to generate and transmit additional parity bits, which are selected based on the number of parity and punctured bits, to achieve coding and diversity gains.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional parity bits are generated and transmitted, then reliability and error correction capability are improved, but device complexity and transmission overhead increase
Solution Approach 1:
The parity bits are segmented into two categories: punctured parity bits (removed from current frame transmission) and additional parity bits (transmitted in previous frame). This segmentation allows the system to distribute error correction information across different time frames, improving reliability without requiring all parity bits to be transmitted simultaneously, thus managing complexity.
Solution Approach 2:
Additional parity bits are generated and transmitted in advance (in the previous frame) before the actual data transmission in the current frame. This preliminary action allows the receiver to have error correction information ready before needing it, improving decoding reliability while allowing the transmitter to use a systematic approach that manages complexity.
2Productivity
If puncturing is applied to reduce transmission overhead, then transmission efficiency is improved, but error correction capability deteriorates
Solution Approach 1:
Specific parity bits are extracted (punctured) from the current frame transmission to improve transmission efficiency. However, to compensate for the removed error correction capability, additional parity bits are extracted from the same LDPC codeword and transmitted in the previous frame, thus maintaining overall error correction capability while achieving transmission efficiency gains.
Solution Approach 2:
The previous frame acts as an intermediary carrier for additional parity bits. Instead of transmitting all parity bits in the current frame (which would reduce efficiency), the system uses the previous frame as a mediator to deliver complementary error correction information, balancing transmission efficiency and reliability.
3Reliability
If repetition is performed to enhance signal reliability, then diversity gain is improved, but transmission overhead and device complexity increase
Solution Approach 1:
The system merges repetition coding with puncturing and additional parity generation into a unified scheme. Instead of simply repeating all bits (which would increase overhead), the repeater selectively repeats only certain parity bits, and these repeated bits are then subject to puncturing and additional parity generation, combining multiple techniques to achieve reliability with controlled overhead.
Solution Approach 2:
Instead of repeating all parity bits excessively (which would increase overhead), the system applies partial repetition only to selected parity bits. This partial action provides sufficient diversity gain for improved reliability while keeping the increase in transmission bits controlled and manageable.
Data Source
AI summary
A transmitter is provided. The transmitter includes: a Low Density Parity Check (LDPC) encoder configured to encode input bits to generate an LDPC codeword including the input bits and parity bits to be transmitted to a receiver in a current frame; a repeater configured to repeat, in the LDPC codeword, at least some bits of the LDPC codeword in the LDPC codeword so that the repeated bits are to be transmitted in the current frame; a puncturer configured to puncture some of the parity bits; and an additional parity generator configured to select at least some bits of the LDPC codeword including the repeated bits, and generate additional parity bits to be transmitted in a previous frame of the current frame.