Non-Uniform Constellation Mapping for Broadcast Transmission

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Solution Overview

Problem

Current broadcasting systems, such as DVB-T2, utilize uniform QAM constellations which leave a significant gap from the theoretical Shannon limit, resulting in suboptimal bit error rate (BER) and frame error rate (FER) performance.

Innovation Solution

The implementation of non-uniform constellations (NUC) that relax the rectangular shape and uniform spacing properties of traditional uniform QAM, optimizing constellation points for better performance based on signal-to-noise ratio (SNR) and coding rate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If uniform QAM constellation is used, then mapping and demapping simplicity is maintained, but performance gap from Shannon limit increases

Engineering Contradiction:

Improvemapping and demapping simplicityVSAvoidBER and FER performance

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent applies parameter changes by transitioning from uniform QAM constellation parameters (equal spacing, rectangular arrangement) to non-uniform constellation parameters (variable spacing, optimized geometry). The constellation points are repositioned based on channel conditions, SNR levels, and coding rates to optimize performance while maintaining manageable complexity through systematic design rules.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If non-uniform constellation is used, then BER and FER performance improves, but mapping and demapping complexity increases

Engineering Contradiction:

ImproveBER and FER performanceVSAvoidmapping and demapping complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements local quality by applying different spacing and positioning characteristics to different regions of the constellation diagram. Rather than uniformly optimizing all points, specific constellation points are adjusted based on their local channel conditions, SNR levels, and coding rate requirements. This allows performance optimization in critical regions while maintaining simpler structures in less critical regions, thereby managing overall complexity.

Inventive Principle:

Principle #3Local quality

3Reliability

If constellation is optimized for specific SNR and coding rate, then performance approaches Shannon limit, but adaptability to varying channel conditions decreases

Engineering Contradiction:

Improveperformance gap from Shannon limitVSAvoidadaptability to channel conditions

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamics by making the constellation configuration adaptable to varying channel conditions. The system dynamically selects or adjusts constellation parameters based on current SNR levels, coding rates, and channel characteristics. This allows the same system to optimize performance across different operating conditions rather than being fixed to a single constellation design, thereby maintaining both performance and adaptability.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS11641214B2Transmitting apparatus and mapping method thereof

Publication Date: 2023.05.02 SAMSUNG ELECTRONICS CO LTD

AI summary

A transmitting apparatus is disclosed. The transmitting apparatus includes an encoder to perform channel encoding with respect to bits and generate a codeword, an interleaver to interleave the codeword, and a modulator to map the interleaved codeword onto a non-uniform constellation according to a modulation scheme, and the constellation may include constellation points defined based on various tables according to the modulation scheme.