LDPC Parity Puncturing for Broadcast Decoding Efficiency
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Solution Overview
Problem
Current signal transmitters and receivers face challenges in providing improved performance for digital broadcasting services, particularly in high-definition digital television and portable broadcasting, due to limitations in efficiently managing parity bits during signal transmission.
Innovation Solution
A transmitter system that includes an LDPC encoder, a puncturer, and a mapper, which calculates the number of parity bits to be punctured based on specific ratios and minimum values, allowing for the puncturing of parity bits to enhance decoding performance by adjusting the number of parity bits according to the number of outer-encoded bits, LDPC information bits, and the minimum number of parity bits, thereby improving transmission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If all parity bits are transmitted, then decoding reliability is improved, but transmission efficiency deteriorates due to increased bandwidth consumption
Solution Approach 1:
The patent extracts and removes a portion of the parity bits from the transmitted signal. Specifically, the transmitter punctures (removes) certain parity bits from the LDPC codeword before transmission, and the receiver compensates for this by inserting dummy bits at known positions. This extraction of unnecessary parity bits reduces transmission bandwidth consumption while maintaining sufficient decoding reliability through the compensation mechanism.
2Reliability
If the number of parity bits is increased, then error correction capability is improved, but signal transmission complexity increases
Solution Approach 1:
The patent changes the parameter of parity bit quantity by introducing a puncturing rate parameter that controls the proportion of parity bits to be removed. The system dynamically adjusts the number of transmitted parity bits based on channel conditions and service requirements, optimizing the balance between error correction capability and transmission complexity without requiring complex adaptive modulation schemes.
3Productivity
If puncturing is applied to reduce bandwidth, then transmission efficiency is improved, but decoding performance deteriorates without proper compensation
Solution Approach 1:
The patent applies preliminary action by having the receiver pre-insert dummy parity bits at known positions before decoding operations. This preliminary compensation ensures that the decoder receives a complete set of parity bits even though some were punctured during transmission, thereby maintaining decoding performance while achieving bandwidth reduction through puncturing.
Data Source
AI summary
A transmitter is provided. The transmitter includes: a Low Density Parity Check (LDPC) encoder configured to encode outer-encoded bits to generate an LDPC codeword including LDPC information bits and parity bits; a puncturer configured to puncture some of the parity bits included in the LDPC codeword; and a mapper configured to map the LDPC codeword except the punctured parity bits to symbols for transmission to a receiver, wherein the puncturer calculates a number of parity bits to be punctured among the parity bits included in the LDPC codeword based on a number of the outer-encoded bits, a number of the LDPC information bits, and a minimum number of parity bits to be punctured among the parity bits included in the LDPC codeword.