LDPC Frame Mapping for Shaping Gain in DVB-NGH Transmission
Find Innovative SolutionsGenerate Solutions
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, L1 signaling information, 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 code lengths (16k, 64k modes) and transmission systems (SISO, MISO, MIMO). Instead of using a single universal mapping pattern, the system optimizes mapping characteristics locally for each combination of code length and transmission mode, thereby achieving maximum shaping gain and error correction performance for each specific case.
Solution Approach 2:
The patent changes the mapping pattern parameters based on code length and transmission system type. By adjusting the non-uniform mapping pattern parameters (such as constellation point distribution and mapping rules) according to specific LDPC code lengths and transmission modes, the system achieves optimal performance for each scenario rather than using fixed parameters from DVB-T2.
2Device complexity
If identical coding rates use the same non-uniform mapping pattern, then system complexity is reduced, but shaping gain optimization is limited
Solution Approach 1:
The patent implements local quality by creating distinct non-uniform mapping patterns for different code lengths even when coding rates are identical. For example, 16k mode and 64k mode each have their own optimized mapping patterns, allowing shaping gain optimization tailored to the specific code length characteristics without increasing overall system complexity through a universal approach.
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 16 k mode or a 64 k 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.