LDPC Parity Permutation and Puncturing for Better Decoding
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Solution Overview
Problem
Current digital broadcasting systems face challenges in providing improved performance and support for various receiving schemes, particularly in high definition digital television and portable broadcasting, due to limitations in signal transmission and reception methods.
Innovation Solution
A transmitter is designed with a Low Density Parity Check (LDPC) encoder, a parity permutator, and a puncturer to perform parity permutation on parity bits by interleaving and puncturing specific parity bits, optimizing their placement and selection to enhance transmission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If parity bits are transmitted without permutation and selective puncturing, then the transmission process is simple, but the decoding performance and error correction capability are insufficient
Solution Approach 1:
The parity bits are divided into multiple groups (first parity bit group, second parity bit group, third parity bit group) with different permutation patterns. This segmentation allows selective puncturing of specific groups while maintaining others, improving error correction performance without requiring complete transmission of all parity bits.
Solution Approach 2:
Different permutation patterns are applied to different parity bit groups based on their specific characteristics and requirements. The first parity bit group uses a first permutation pattern, the second group uses a second pattern, and the third group uses a third pattern. This local differentiation optimizes the overall system performance by tailoring the treatment to each group's needs.
2Productivity
If all parity bits are transmitted, then error correction capability is maximized, but transmission efficiency and bandwidth utilization are reduced
Solution Approach 1:
Specific parity bit groups are extracted and punctured (removed) from the transmission stream based on channel conditions and system requirements. By selectively removing the third parity bit group for example, the system reduces transmission overhead while maintaining sufficient error correction capability through the remaining parity bit groups.
Solution Approach 2:
Instead of transmitting all parity bits or none, the system transmits only the necessary portion (partial action). The selective puncturing mechanism allows the system to transmit fewer parity bits than the maximum when channel conditions permit, thereby improving transmission efficiency while maintaining adequate error correction capability.
3Adaptability or versatility
If uniform permutation pattern is applied to all parity bit groups, then the processing is simple, but the adaptability to different receiving schemes is limited
Solution Approach 1:
Different permutation patterns are applied to different parity bit groups based on their specific characteristics and requirements. The first parity bit group uses a first permutation pattern, the second group uses a second pattern, and the third group uses a third pattern. This local differentiation optimizes the overall system performance by tailoring the treatment to each group's needs.
Solution Approach 2:
The transmission system is designed to support multiple receiving schemes through its configurable parity bit permutation and puncturing mechanism. By implementing different permutation patterns for different parity bit groups, the system can adapt to various channel conditions and receiver capabilities, providing universal support for diverse receiving schemes including high definition digital television and portable broadcasting.
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 parity bits; a parity permutator configured to perform parity permutation by interleaving the parity bits and group-wise interleaving a plurality of bit groups including the interleaved parity bits; and a puncturer configured to select some of the parity bits in the group-wise interleaved bit groups, and puncture the selected parity bits, wherein the parity permutator group-wise interleaves the bit groups such that some of the bit groups are positioned at predetermined positions, respectively, and a remainder of the bit groups are positioned without an order within the group-wise interleaved bit groups so that the puncturer selects parity bits included in the some of the bit groups positioned at the predetermined positions sequentially and selects parity bits included in the remainder of the bit groups without an order.