Multi-Peak Constellation Shaping to Reduce Fiber Nonlinearity
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Solution Overview
Problem
Existing communication systems, particularly fiber-optic systems, suffer from impairments due to Gaussian noise and nonlinearity issues, which are exacerbated by probabilistic constellation shaping (PCS) methods, leading to higher peak-to-average power ratios and increased error rates.
Innovation Solution
A data processing device and method that generates output information bits following a distribution with multiple local maxima, reducing the probability of assigning signals to low-energy constellation points, thereby suppressing signal transmission impairments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If probabilistic constellation shaping (PCS) method is implemented to achieve optimal capacity in AWGN channel, then transmission capacity is improved, but nonlinearity impairments become more severe leading to higher peak-to-average power ratio and higher error rate
Solution Approach 1:
The patent changes the probability distribution parameter from a single-peak distribution to a multi-peak distribution. Specifically, it uses a distribution with multiple local maxima instead of the conventional single maximum, which alters how constellation points are selected and reduces the peak-to-average power ratio while maintaining transmission capacity
Solution Approach 2:
Instead of concentrating probability on low-energy points as in conventional PCS, the patent inverts the approach by using a distribution that spreads probability across multiple peaks, including higher energy points, thereby reducing the harmful concentration of power at low energy levels
2Productivity
If signals are assigned to low-energy constellation points with high probability, then spectral efficiency is improved, but peak-to-average power ratio increases leading to higher nonlinearity impairments
Solution Approach 1:
The patent modifies the probability distribution parameters to create multiple local maxima, changing how constellation points are weighted. This parameter change ensures that while spectral efficiency is maintained, the peak-to-average power ratio is reduced by distributing probability across multiple energy levels rather than concentrating it
3Ease of manufacture
If conventional probability distribution with single maximum is used, then implementation is simple, but nonlinearity impairments are severe
Solution Approach 1:
The patent changes the distribution shape parameter from single-peak to multi-peak configuration. This parameter modification maintains the basic probabilistic shaping framework (keeping implementation relatively simple) while dramatically improving signal transmission quality by reducing nonlinearity impairments
Data Source
AI summary
An object of the present disclosure is to provide a data processing device, a data processing method and a non-transitory computer readable medium capable of suppressing impairments of signal transmission. A data processing device includes at least one memory configured to store instructions and at least one processor configured to execute the instructions to: obtain input information bits; and generate a first output information bits and a second output information bits based on the input information bits, wherein the first output information bits correspond to constellation points of a constellation diagram on a first axis and the second output information bits correspond to constellation points of the constellation diagram on a second axis, and a probability of the constellation points on at least one of the first or the second axis follows a distribution, the distribution having a plurality of local maxima.