M-ASK Constellation Probabilistic Shaping for Non-Gaussian Channels
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Solution Overview
Problem
Existing methods for transmitting binary data using M-ASK constellations are complex and difficult to implement, especially when trying to fit the Maxwell-Boltzmann distribution, and they are not well adapted to non-Gaussian channels.
Innovation Solution
A method for transmitting binary data using an M-ASK constellation divided into M/2 sets of two symbols, where each set is associated with specific probabilities for transmitting the first or second symbol, and each symbol is associated with a binary word using natural or Gray labelling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If probabilistic shaping is implemented using Maxwell-Boltzmann distribution to approach channel capacity, then energy efficiency is improved, but implementation complexity increases
Solution Approach 1:
The M-ASK constellation is divided into M/2 sets of two symbols, where each set contains symbols with complementary probabilities (pi and 1-pi). This segmentation allows the complex probabilistic shaping to be broken down into simpler binary source selections, reducing implementation complexity while maintaining energy efficiency.
Solution Approach 2:
The patent uses binary sources that output bits with probabilities matching the desired symbol probabilities. Instead of directly implementing complex Maxwell-Boltzmann distribution processing, the patent copies the probability structure through multiple binary sources, each associated with a specific probability pi, thereby simplifying the overall implementation.
2Reliability
If conventional probabilistic shaping methods are used, then performance on Gaussian channels is improved, but adaptability to non-Gaussian channels deteriorates
Solution Approach 1:
The patent dynamically adapts the binary source selection based on the channel characteristics. By associating each binary source with specific probability pi and allowing flexible selection based on channel conditions, the system can adapt to different channel types (Gaussian or non-Gaussian) while maintaining optimal performance.
Solution Approach 2:
The patent changes the probability parameters pi of the binary sources to match the specific channel characteristics. For different channels, the probabilities pi can be adjusted, allowing the same framework to work optimally across various channel conditions without requiring fundamentally different approaches.
3Ease of manufacture
If M-ASK constellation is divided into M/2 sets with specific probability assignments, then implementation simplicity is improved, but the number of required binary sources increases
Solution Approach 1:
Multiple binary sources are merged into a unified selection framework where m-1 bits select among 2^(m-1) binary sources. This merging allows the system to manage the number of binary sources systematically through bit-based indexing, simplifying the overall structure despite having multiple sources.
Solution Approach 2:
The patent introduces an intermediary selection mechanism where m-1 bits from a binary source act as an index to select the appropriate binary source. This intermediary layer simplifies the management of multiple binary sources by providing a systematic selection process rather than direct complex control.
Data Source
AI summary
A method for transmitting binary data using an M-ASK constellation divided into M/2 sets of two symbols is disclosed. Each set of index i is associated with a probability pi of transmitting the first symbol of the set. First, m−1 bits are obtained from a binary source where m=log2M. A binary source is then selected in a plurality of binary sources responsive to said m−1 bits, each binary source of index i being associated with a probability of outputting a bit zero equal to pi. A symbol of the M-ASK constellation is obtained that is associated with the binary word formed by the m−1 bits and the bit obtained from the selected source. The symbol is finally transmitted to a receiver over a communication channel.