LDPC De-Interleaving Bit Mapping for Digital Broadcast Reception
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for improved methods to support high decoding and receiving performance in digital broadcasting services, particularly in a digitalization era with increasing demands for multi-channel, wideband, and high-quality broadcasting.
Innovation Solution
A transmitting apparatus and interleaving method that utilize an LDPC encoder, interleaver, and modulator to map bits from a predetermined bit group of an LDPC codeword onto modulation symbols, employing a parity check matrix and cyclic shift parameters to optimize bit arrangement and interleaving.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional digital broadcasting methods are used, then basic transmission is achieved, but decoding and receiving performance is insufficient for high-quality multi-channel wideband services
Solution Approach 1:
The LDPC codeword is divided into multiple bit groups, and each bit group is further segmented into sub-bit groups for selective mapping. This segmentation allows the system to process and transmit different portions of the codeword with different mapping strategies, improving decoding performance while managing complexity through structured division of the data stream.
Solution Approach 2:
Different bit groups within the LDPC codeword are mapped to different bit positions of modulation symbols based on their importance and error protection requirements. Specifically, bits from certain bit groups are mapped to more reliable bit positions in the modulation constellation, while less critical bits are mapped to less reliable positions. This local differentiation optimizes the overall receiving performance by ensuring that critical information is transmitted with higher reliability.
2Reliability
If bit mapping is performed without selective group arrangement, then transmission simplicity is maintained, but decoding performance deteriorates due to poor error protection distribution
Solution Approach 1:
Before modulation and transmission, the system performs preliminary interleaving and selective mapping of bit groups from the LDPC codeword onto modulation symbols. This preliminary arrangement ensures that bits requiring stronger error protection are mapped to more reliable positions in the modulation constellation before transmission begins, optimizing decoding performance without requiring complex real-time adjustments during reception.
Solution Approach 2:
The bit group selection and mapping process acts as an intermediary between the LDPC encoding stage and the modulation stage. By selectively choosing which bit groups to map to which modulation symbol bits, the system creates an intermediate representation that optimizes error protection distribution. This intermediary mapping layer allows the system to bridge the gap between the structured LDPC codeword and the modulation scheme, achieving improved error protection without requiring fundamental changes to either the encoder or modulator.
Data Source
AI summary
A transmitting apparatus and a receiving apparatus are provided. The transmitting apparatus includes: an encoder configured to generate a low density parity check (LDPC) codeword by LDPC encoding based on a parity check matrix; an interleaver configured to interleave the LDPC codeword; and a modulator configured to map the interleaved LDPC codeword onto a modulation symbol, wherein the modulator is further configured to map a bit included in a predetermined bit group from among a plurality of bit groups constituting the LDPC codeword onto a predetermined bit of the modulation symbol.