Probabilistic Signal Point Shaping for BICM Capacity
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Solution Overview
Problem
Existing probabilistic signal point shaping devices and methods fail to optimize Bit-Interleaved-Coded-Modulation (BICM) capacity effectively, especially in multi-user scenarios and channels other than Additive White Gaussian Noise (AWGN), limiting link throughput and bandwidth efficiency.
Innovation Solution
A mapping device and method that employs probabilistic signal point shaping with non-uniform signal point constellations and simultaneous IQ distribution matching, allowing for flexible signal point positioning and probability distribution, enabling efficient communication over various channels and multi-user scenarios through superposition coding and constant composition distribution matching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional probabilistic signal point shaping is used, then signal point optimization can be achieved, but BICM capacity is not optimized in multi-user scenarios and channels other than AWGN
Solution Approach 1:
The patent applies parameter changes by extending probabilistic signal point shaping to handle multiple channels with different characteristics (not just AWGN) and multi-user scenarios. The system dynamically adjusts signal point probabilities and positions based on channel conditions and user requirements, enabling optimization of BICM capacity across diverse communication environments rather than being limited to a single channel model.
Solution Approach 2:
The invention achieves universality by creating a unified framework that can handle multiple channel types (AWGN and non-AWGN) and multi-user scenarios simultaneously. The constant composition distribution matching mechanism works universally across different channels and user configurations, making the system adaptable to various communication scenarios without requiring separate optimization for each case.
2Productivity
If non-uniform signal point constellations are used, then bandwidth efficiency improves, but device complexity increases
Solution Approach 1:
The patent manages device complexity while achieving bandwidth efficiency by parameterizing the signal point constellation through probability distributions rather than fixed geometric configurations. The constant composition distribution matching algorithm systematically generates non-uniform constellations by adjusting probability parameters, which simplifies the design process compared to manually optimizing each constellation point while maintaining high bandwidth efficiency.
Solution Approach 2:
The system incorporates feedback mechanisms where the mapping device monitors channel conditions and user requirements to dynamically adjust signal point probabilities. This feedback loop enables the system to optimize bandwidth efficiency in real-time without requiring complex pre-configured constellation designs, as the parameters are adapted based on actual system performance and requirements.
Data Source
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AI summary
A mapping device comprises circuitry configured to map data blocks of input bits of a first input bit stream onto first mapping symbols, wherein said first mapping symbols are distributed according to a first predetermined probability distribution and represented by first signal points, analyze the probability of occurrence of the first signal points representing the first mapping symbols and/or earlier final mapping symbols, determine a second probability distribution to be applied for mapping second inputbits of a second input bit stream onto second mapping symbols, said second probability distribution being determined based on the analyzed probability of occurrence such that a desired final probability distribution of final mapping symbols is obtained, map data blocks of input bits of a second input bit stream onto second mapping symbols, wherein said second mapping symbols are distributed according to said second probability distribution and represented by second signal points, and combine the first mapping symbols and the second mapping symbols into the final mapping symbols.