Probabilistic Constellation Shaping for Lower-Power Optical Encoding
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Solution Overview
Problem
Optical communication systems face challenges in increasing bandwidth demands due to channel impairments and high power consumption, necessitating improved constellation shaping techniques to optimize signal quality and reduce power usage.
Innovation Solution
Implementing probabilistic constellation shaping through a recursive constant composition distribution matcher encoding procedure to map information bits to transmission symbols, limiting the transmission of high-energy symbols and optimizing the distribution of transmission symbol amplitudes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional constellation shaping is used to increase bandwidth capacity, then communication bandwidth is improved, but power consumption increases due to frequent transmission of high-energy symbols
Solution Approach 1:
The patent applies parameter changes by modifying the probability distribution of constellation symbol amplitudes. Specifically, it uses probabilistic constellation shaping to adjust the amplitude parameters of transmission symbols, making high-energy symbols less probable and low-energy symbols more probable. This changes the statistical parameters of the transmitted signal to optimize the trade-off between bandwidth efficiency and power consumption, directly resolving the technical contradiction by transforming the energy distribution parameters of the communication signal.
2Productivity
If high-energy transmission symbols are transmitted frequently to increase data rate, then communication capacity is improved, but signal quality deteriorates due to channel impairments
Solution Approach 1:
The patent changes the amplitude parameter distribution of transmission symbols by implementing probabilistic constellation shaping. It adjusts the probability parameters so that symbols with amplitudes closer to the channel noise threshold are transmitted less frequently, while symbols with amplitudes further from the threshold are transmitted more frequently. This parameter optimization improves signal quality and reliability while maintaining acceptable data rates by transforming the statistical characteristics of the transmitted signal to better match channel conditions.
Data Source
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AI summary
A transmitter generates a set of transmission symbols corresponding to a set of information bits. Generating the set of transmission symbols includes: performing probabilistic constellation shaping to set, in the set of transmission symbols, a quantity n1 of transmission symbols having a maximum transmission symbol amplitude value. Performing of the probabilistic constellation shaping includes performing a recursive procedure to map the set of information bits to a set of amplitude indicators that corresponds to amplitudes of transmission symbols. The set of amplitude indicators includes n1 amplitude indicators set to indicate the maximum transmission symbol amplitude value.