LDPC Bit-Group Mapping and Interleaving for Broadcast Decoding
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Solution Overview
Problem
There is a need for improved decoding and receiving performance in digital broadcasting services, particularly in high-quality digital television and portable multimedia systems, where existing methods do not adequately support various receiving methods and fail to provide enhanced user experiences.
Innovation Solution
A transmitting apparatus and method that employs an LDPC codeword encoder, interleaver, and modulator to map bits from a predetermined bit group onto a modulation symbol, using a parity check matrix and cyclic shift parameters to optimize bit arrangement and interleaving, thereby enhancing decoding and receiving performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional transmission methods are used, then device complexity is reduced, but decoding and receiving performance deteriorates
Solution Approach 1:
The LDPC codeword is divided into multiple bit groups, and these bit groups are further segmented into information bit groups and parity bit groups. This segmentation allows for targeted interleaving operations on different parts of the codeword, improving decoding performance while managing complexity through structured division.
Solution Approach 2:
The patent introduces a two-dimensional interleaving structure where bit groups are arranged in rows and columns. The group interleaver operates on the row dimension by reordering bit groups, while the block interleaver operates on the column dimension by interleaving bits within groups. This dimensional approach enhances performance without linearly increasing complexity.
2Reliability
If bit groups are interleaved to improve receiving performance, then decoding performance is improved, but processing complexity increases
Solution Approach 1:
The group interleaver performs preliminary interleaving of bit groups before the block interleaver processes individual bits. By pre-arranging bit groups in an optimized order based on modulation and code rate, the subsequent block interleaving operation becomes more efficient, and the receiver can apply the same preliminary arrangement to facilitate faster decoding.
Solution Approach 2:
The interleaving structure is made dynamic by configuring the number of columns in the block interleaver based on modulation order and code rate. The group interleaver reorders bit groups according to these parameters, and the block interleaver adapts its column structure accordingly. This dynamic configuration optimizes performance for different transmission conditions without requiring completely different interleaving schemes.
Data Source
AI summary
A transmitting apparatus is 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.