Non-uniform Bit Sequence Mapping for Gaussian Shaping Gain

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Solution Overview

Problem

Current modulation schemes in telecommunication networks do not efficiently map a plurality of bit sequences to signal points, resulting in suboptimal shaping gain and channel capacity utilization.

Innovation Solution

A method that determines the number of bit sequences to be mapped to each signal point according to a discrete Gaussian distribution, selecting sets that minimize the maximal Hamming distance among the selected sets, ensuring each bit sequence is mapped uniquely to a signal point, and optimizing the distribution to approach a Gaussian distribution for improved channel efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If natural mapping is used to map bit sequences to signal points, then the mapping process is simple, but the shaping gain is not optimal

Engineering Contradiction:
Improvemapping process simplicityVSAvoidshaping gain
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the mapping parameters by distributing bit sequences non-uniformly across signal points according to a discrete Gaussian distribution, rather than using uniform natural mapping. This parameter change optimizes the shaping gain while maintaining implementation feasibility through systematic selection rules.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If uniform mapping is used, then the mapping is straightforward, but the channel capacity utilization is suboptimal

Engineering Contradiction:
Improvemapping operation simplicityVSAvoidchannel capacity utilization
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent transforms the uniform mapping parameter into a non-uniform discrete Gaussian distribution parameter, which optimizes channel capacity utilization. The systematic selection process based on Hamming distance ensures the transformation maintains operational simplicity.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If bit sequences are mapped to minimize Hamming distance, then the mapping efficiency improves, but the selection process becomes more complex

Engineering Contradiction:
Improvemapping efficiencyVSAvoidselection process complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-determining the discrete Gaussian distribution parameters and preparing the selection criteria before the actual mapping process. This preliminary preparation reduces the complexity during real-time operation while maintaining high mapping efficiency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses parameter changes by transforming the selection criterion into a systematic rule based on Hamming distance thresholds and discrete Gaussian distribution characteristics, which simplifies the complex selection process into manageable steps.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2798807B1Method for non-uniform mapping of bit sequences and a corresponding device
Publication Date: 2019.05.01 ORANGE SA
  • EP2798807B1 patent drawingFigure 1~2
  • EP2798807B1 patent drawingFigure 3~4
  • EP2798807B1 patent drawingFigure 5

AI summary

A method of mapping a plurality of different bit sequences (u) to a plurality of different signal points (x) in a constellation, the number of bit sequences (u) being greater than the number of signal points (x), said method comprising, for a device in a telecommunication network, the acts of: - determining, for each signal point (x) in the constellation, a number of bit sequences (u) to be mapped to said each signal point (x), the numbers of bit sequences (u) being distributed according to a discrete Gaussian distribution among the constellation, - selecting in the plurality of bit sequences (u), for each signal point (x) in the constellation, a set comprising the determined number of bit sequences (u) that minimize the maximal Hamming distance among the selected sets.