LDPC Bit-to-Cell Permutation for 256QAM Reception Reliability

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Solution Overview

Problem

The reception performance of a receiver can be improved by optimizing the permutation rules applied to LDPC codeword bits prior to mapping, specifically for LDPC codes and constellations used in transmitters and receivers, to enhance the association between bits and constellation symbols.

Innovation Solution

A transmission processing method that includes encoding information bits into a low-density parity check code with a code rate of 7/15 and codeword length of 16200, followed by bit-interleaving with parity and column-row interleaving, and bit-to-cell demultiplexing with a predetermined permutation rule, such as v0=b2, v1=b6, v2=b0, v3=b1, v4=b4, v5=b5, v6=b3, v7=b7, before mapping to a 256QAM constellation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If standard bit-interleaving and demultiplexing rules are used, then the system is compatible with existing standards, but reception performance is not optimized for specific LDPC codes and constellations

Engineering Contradiction:

Improvereception performanceVSAvoidpermutation rule complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by modifying the permutation rules in the bit-to-cell demultiplexing step. Specifically, different permutation patterns (e.g., v0=b2, v1=b6, v2=b0, v3=b1, v4=b4, v5=b5, v6=b3, v7=b7) are used depending on the LDPC code rate and constellation type. This optimization of permutation parameters improves reception performance without adding significant system complexity.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If permutation rules are optimized for specific LDPC codes and constellations, then reception performance improves, but the system becomes less adaptable to different code and modulation combinations

Engineering Contradiction:

Improvereception performanceVSAvoidadaptability to different LDPC codes and constellations

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamics by making the permutation rules adaptive rather than fixed. The system dynamically selects appropriate permutation patterns based on the LDPC code rate and modulation constellation being used. This allows the system to optimize reception performance for each specific combination while maintaining adaptability across different code and modulation types.

Inventive Principle:

Principle #15Dynamics

3Productivity

If simple demultiplexing without permutation is used, then processing is faster and simpler, but bit association with constellation symbols is suboptimal

Engineering Contradiction:

Improveprocessing speedVSAvoidbit association accuracy

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-defining optimized permutation patterns for different LDPC code rates and constellation types. These permutation rules are determined in advance and stored for quick reference during operation. This allows the system to perform fast look-up and application of optimal permutation rules without real-time computation, thus maintaining high processing speed while achieving optimal bit association accuracy.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS8837618B2Transmission processing method, transmitter, reception processing method, and receiver

Publication Date: 2014.09.16 SUN PATENT TRUST

AI summary

Information bits are encoded according to a low density parity check code with code rate 7/15 and a codeword length of 16200. The resulting codeword bits are bit-interleaved and the interleaved bits are demultiplexed into 8 sequences of bits. The 8 sequences of bits are permuted according to a predetermined permutation rule: v0=b2, v1=b6, v2=b0, v3=b1, v4=b4, v5=b5, v6=b3, v7=b7.