Distribution Matcher Architecture for Coherent Optical Probabilistic Shaping

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Solution Overview

Problem

Existing optical communication systems face challenges with data misalignment due to delay in channels, leading to degraded data recovery, and are limited by large size, high power consumption, and performance limitations.

Innovation Solution

The implementation of distribution matcher encoders and decoders for probabilistic shaping applications, using hardware or software configurations, which avoid arithmetic coding and combine with LDPC codes through reverse concatenation techniques, leveraging LUTs and adders for high parallelism and throughput in optical communications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional optical communication systems are used, then data can be transmitted through multiple channels, but delay and skew in channels cause data misalignment and degradation of recovered data

Engineering Contradiction:
Improvedata recovery qualityVSAvoiddata misalignment
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The system performs preliminary synchronization and equalization operations before data recovery to compensate for anticipated delay and skew effects. Training sequences and pilot signals are transmitted beforehand to establish timing and phase references that are used to correct data alignment in subsequent transmission intervals.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements feedback mechanisms where the receiver detects misalignment and sends control signals back to the transmitter to adjust timing and phase parameters. Adaptive equalizers continuously monitor channel conditions and modify their coefficients to optimize data recovery despite varying delay and skew conditions.

Inventive Principle:
Principle #23Feedback

2Productivity

If traditional arithmetic coding methods are used for probabilistic shaping, then data compression is achieved, but the implementation requires large area and high power consumption

Engineering Contradiction:
Improvespectral efficiencyVSAvoidpower consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent replaces traditional arithmetic coding mechanisms with a look-up table (LUT) based system. Instead of performing complex arithmetic operations that require significant computational resources, the system uses pre-computed tables stored in memory to map input symbols to output symbols, dramatically reducing power consumption while maintaining the same probabilistic shaping performance.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system creates simplified copies of the arithmetic coding functionality through LUTs. Rather than implementing the full arithmetic coding algorithm, pre-computed mapping tables capture the essential transformation behavior, allowing the system to achieve the same compression effect with much simpler, lower-power hardware.

Inventive Principle:
Principle #26Copying

3Reliability

If complex error correction codes are implemented, then coding efficiency is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvecoding efficiencyVSAvoidimplementation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The error correction system is divided into separate functional modules: encoding module, modulation module, transmission module, demodulation module, and decoding module. Each module performs a specific function and can be independently optimized and tested. This segmentation reduces manufacturing complexity by allowing specialized fabrication processes for each module while maintaining overall high coding efficiency.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS12081274B1Probabilistic shaping techniques for high performance coherent optical transceivers
Publication Date: 2024.09.03 MARVELL ASIA PTE LTD
  • US12081274B1 patent drawing
  • US12081274B1 patent drawing
  • US12081274B1 patent drawing

AI summary

A method and structure for probabilistic shaping and compensation techniques in coherent optical receivers. According to an example, the present invention provides a method and structure for an implementation of distribution matcher encoders and decoders for probabilistic shaping applications. The techniques involved avoid the traditional implementations based on arithmetic coding, which requires intensive multiplication functions. Furthermore, these probabilistic shaping techniques can be used in combination with LDPC codes through reverse concatenation techniques.