LDPC Bit Interleaving for Robust Digital Broadcast Modulation
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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 multi-channel and wideband environments, where existing standards fall short in meeting user demands for improved service quality.
Innovation Solution
A transmitter apparatus and signal processing method that employs Low Density Parity Check (LDPC) coding, including an encoder, interleaver, and modulator to map bits from LDPC codewords onto modulation symbols, utilizing a specific interleaving scheme based on the length of the LDPC codeword, modulation method, and code rate to enhance decoding and receiving performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional encoding and modulation schemes are used in digital broadcasting systems, then system simplicity is maintained, but decoding and receiving performance are insufficient for high-quality digital services in multi-channel and wideband environments
Solution Approach 1:
The LDPC codeword is divided into multiple groups (e.g., 360 bits per group), and different interleaving schemes are applied to different groups based on their positions. This segmentation allows the system to achieve improved decoding performance through structured processing while maintaining manageable complexity by handling each group independently with predefined rules.
Solution Approach 2:
The patent employs variable interleaving parameters including different code rates (e.g., 6/15, 8/15, 10/15, 12/15), modulation methods (e.g., 256-QAM), and LDPC codeword lengths (e.g., 64800 bits). These parameter changes enable the system to adapt to different service requirements and channel conditions, improving receiving performance while maintaining systematic control over complexity.
2Reliability
If LDPC coding with complex interleaving schemes is implemented, then decoding and receiving performance is improved, but system implementation complexity increases
Solution Approach 1:
The patent applies preliminary interleaving operations to LDPC codewords before modulation, with specific arrangements defined in advance for different code rates and modulation schemes. This preliminary action ensures that the most complex processing is performed systematically before transmission, improving robustness while allowing the receiver to use corresponding predetermined deinterleaving operations.
Solution Approach 2:
Different interleaving patterns and schemes are applied to different portions of the LDPC codeword based on local requirements. For example, specific groups of bits are interleaved differently depending on their position and the intended modulation scheme, allowing optimized performance for each segment while maintaining overall system coherence.
Data Source
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.