Group-Wise LDPC Interleaving for 12/15 Rate Modulation Mapping
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Solution Overview
Problem
Current digital broadcasting systems face challenges in providing robust encoding and decoding performance for high-quality digital services, particularly in handheld devices, due to limitations in bit interleaving and modulation techniques.
Innovation Solution
A transmitter apparatus and signal processing method that maps bits from a Low Density Parity Check (LDPC) codeword onto modulation symbols, utilizing a specific interleaving method involving a parity check matrix and block interleaver to enhance decoding and receiving performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional bit interleaving methods are used in digital broadcasting systems, then the system can maintain simpler implementation, but decoding and receiving performance is insufficient for high-quality digital services
Solution Approach 1:
The LDPC codeword is divided into multiple groups of bits, and a group-wise interleaver is introduced to permute these groups before mapping to modulation symbols. This segmentation approach improves decoding performance by better distributing error patterns across code blocks, while the structured group-wise approach keeps implementation complexity manageable.
Solution Approach 2:
Different interleaving strategies are applied to different parts of the transmission system: a parity interleaver for parity bits, a group-wise interleaver for codeword groups, and a block interleaver for final symbol mapping. This localized optimization of interleaving quality for different data types enhances overall reliability without uniformly increasing complexity throughout the entire system.
2Reliability
If robust encoding and decoding performance is achieved through advanced interleaving, then service quality improves, but system complexity increases
Solution Approach 1:
The interleaver structure is made adaptable to different transmission conditions and service requirements. The group-wise interleaver can be configured with different parameters (such as group size and permutation patterns) depending on the specific broadcasting service, allowing the system to optimize performance for different scenarios without requiring a completely different interleaver design for each case.
Solution Approach 2:
The interleaving parameters such as group size, number of groups, and permutation patterns can be adjusted based on channel conditions and service requirements. By changing these parameters dynamically, the system achieves robust performance across different scenarios while maintaining a relatively simple base interleaver structure that doesn't require complete redesign for each application.
Data Source
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AI summary
A transmitter apparatus and a receiver apparatus are provided. The transmitter apparatus includes: an encoder configured to generate a low density parity check (LDPC) by performing LDPC encoding; an interleaver configured to interleave the LDPC codeword; and a modulator configured to map the interleaved LDPC codeword onto a modulation symbol. The modulator maps a bit included in a predetermined group from among a plurality of groups constituting the LDPC codeword onto a predetermined bit in the modulation symbol.