Non-Uniform LDPC Mapping for DVB-NGH Code-Length Shaping
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Solution Overview
Problem
The DVB-NGH system faces challenges in obtaining maximum shaping gain due to the direct adaptation of non-uniform mapping patterns from the DVB-T2 system, particularly with the 64 k mode, 4 k mode, and MIMO profiles, which results in suboptimal error correction capabilities and increased C/N ratios.
Innovation Solution
A transmission device and method that selectively maps error correction coded frames in non-uniform patterns based on predetermined lengths, even when coding rates are identical, allowing for efficient shaping gain optimization by defining distinct non-uniform mapping patterns for different LDPC code lengths and transmission systems like SISO, MISO, and MIMO.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If non-uniform mapping patterns from DVB-T2 system are directly adapted to DVB-NGH system, then implementation simplicity is improved, but shaping gain and error correction capabilities deteriorate
Solution Approach 1:
The patent applies local quality by defining different non-uniform mapping patterns tailored to specific DVB-NGH transmission scenarios (64 k mode, 4 k mode, MIMO profiles) rather than using a universal mapping pattern from DVB-T2. Each mode receives optimized mapping characteristics appropriate to its specific requirements, achieving both implementation feasibility and performance optimization.
Solution Approach 2:
The patent changes the mapping pattern parameters specifically for DVB-NGH system requirements. By adjusting the non-uniform mapping patterns to match DVB-NGH's error correction capabilities and transmission characteristics, the system achieves maximum shaping gain while maintaining implementation simplicity through structured parameter definitions.
2Device complexity
If identical non-uniform mapping patterns are used for different code lengths, then system complexity is reduced, but transmission efficiency and shaping gain deteriorate
Solution Approach 1:
The patent defines distinct non-uniform mapping patterns for different LDPC code lengths (64 k mode, 4 k mode) and transmission systems (SISO, MISO, MIMO). This localized optimization ensures each code length receives mapping characteristics optimized for its specific error correction capabilities, maximizing transmission efficiency without excessive system complexity.
3Productivity
If non-uniform mapping patterns are optimized for maximum shaping gain, then transmission efficiency is improved, but C/N ratio requirements increase
Solution Approach 1:
The patent adjusts mapping pattern parameters to achieve optimal balance between shaping gain and C/N ratio requirements. By carefully designing the non-uniform mapping patterns for DVB-NGH specific requirements, the system achieves maximum transmission efficiency while maintaining acceptable C/N ratio performance for portable and mobile reception.
Data Source
AI summary
An FEC coder in a transmission device according to an exemplary embodiment of the present disclosure performs BCH coding and LDPC coding based on whether a code length of the LDPC coding is a 16k mode or a 64k mode. A mapper performs mapping in an I-Q coordinate to perform conversion into an FEC block, and outputs pieces of mapping data (cells). The mapper defines different non-uniform mapping patterns with respect to different code lengths even an identical coding rate is used by the FEC coder. This configuration improves a shaping gain for different error correction code lengths in a transmission technology in which modulation of the non-uniform mapping pattern is used.