Non-uniform QAM Constellation for DVB-C2 Noise Robustness

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Solution Overview

Problem

Current digital broadcasting technologies, such as DVB-C2, face challenges in efficiently transmitting and receiving digital video broadcasting signals over cable systems, particularly in maintaining data transmission efficiency and robustness against noise, especially with increasing data sizes and channel numbers.

Innovation Solution

The method employs Quadrature Amplitude Modulation (QAM) using Binary Reflected Gray Code (BRGC) to create a Non-uniform QAM (NU-QAM) constellation, which optimizes power distribution and increases the minimum Euclidean distance, allowing for more robust noise resistance with reduced energy consumption or equivalent performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional QAM modulation is used in DVB-C2 systems, then data transmission capacity is maintained, but noise robustness deteriorates and energy efficiency is reduced

Engineering Contradiction:
Improvenoise robustnessVSAvoidenergy efficiency
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies parameter changes by transitioning from conventional uniform QAM modulation to non-uniform QAM (NU-QAM) with optimized constellation points. The minimum Euclidean distance between constellation points is increased while maintaining the same data transmission capacity, thereby improving noise robustness and energy efficiency without sacrificing transmission rate

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements local quality by creating non-uniform spacing between constellation points in the NU-QAM diagram. Critical regions with higher noise susceptibility receive greater separation distance, while less critical regions maintain tighter spacing, optimizing the overall noise robustness and energy efficiency of the transmission system

Inventive Principle:
Principle #3Local quality

2Productivity

If data size and number of broadcasting channels are increased, then service capacity is improved, but data transmission efficiency deteriorates

Engineering Contradiction:
Improveservice capacityVSAvoiddata transmission efficiency
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The patent applies segmentation by dividing the broadcasting system into multiple Physical Layer Pipes (PLPs), each capable of independent transmission with optimized parameters. This allows efficient handling of large data sizes and multiple channels by organizing them into manageable segments that can be transmitted and managed separately, preventing information loss and maintaining transmission efficiency

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2187556B1Apparatus and method for transmitting and receiving a broadcasting signal
Publication Date: 2013.01.16 LG ELECTRONICS INC
  • EP2187556B1 patent drawingFigure 1~2
  • EP2187556B1 patent drawingFigure 3~4
  • EP2187556B1 patent drawingFigure 5

AI summary

The present invention relates to method of transmitting and receiving signals and a corresponding apparatus. One aspect of the present invention relates to a method of receiving a signal, which includes an efficiently time interleaved L1 block.