Enumerative Coding for QAM Symbol Probability Control
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Solution Overview
Problem
Current data communication systems face challenges in efficiently modulating and demodulating data signals, particularly in quadrature amplitude modulation, where controlling the probability distribution of symbol amplitudes to optimize transmission performance is complex.
Innovation Solution
The apparatus employs registers and adder logic to update index values and Hamming Weights based on coefficients, using enumerative coding to control the probability distribution of symbols in the codeword, allowing for efficient modulation and demodulation by determining symbol-dependent conditions and updating register values accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If quadrature amplitude modulation is used to vary amplitudes of carrier signals, then data transmission capability is improved, but control complexity of symbol amplitude probability distribution increases
Solution Approach 1:
The patent pre-calculates and stores binomial coefficients in a lookup table before the actual modulation process. This preliminary preparation allows the system to quickly access pre-computed values during real-time operation, avoiding complex calculations and reducing control complexity while maintaining the ability to control symbol amplitude probability distribution in QAM systems
Solution Approach 2:
The patent introduces binomial coefficients as an intermediary element that mediates between the input data and the QAM modulation process. These coefficients serve as a bridge that simplifies the control of symbol amplitude probability distribution by providing a mathematical framework that transforms complex probability control into simpler coefficient-based operations
2Reliability
If complex calculations are performed for probability distribution control, then transmission performance is improved, but computational time increases
Solution Approach 1:
The patent performs complex binomial coefficient calculations in advance and stores them in a lookup table. During actual transmission, the system simply retrieves pre-computed values rather than calculating them in real-time, significantly reducing computational time while maintaining the accuracy needed for optimal transmission performance
Solution Approach 2:
Instead of calculating probability distributions during real-time modulation, the patent inverts the approach by pre-calculating the binomial coefficients that define these distributions. This inversion transforms a time-consuming real-time calculation problem into a simple table lookup operation
3Measurement precision
If binomial coefficients are calculated precisely, then probability distribution accuracy is improved, but hardware resource consumption increases
Solution Approach 1:
The patent pre-calculates binomial coefficients with high precision and stores them in a lookup table. This allows the system to use precise coefficients without requiring complex hardware for real-time calculation, as the precise values are prepared in advance and simply retrieved during operation
Solution Approach 2:
The patent creates a copy of the binomial coefficients in the form of a lookup table that can be stored in memory. This copied representation allows the system to access precise coefficient values without needing the computational infrastructure to recalculate them, reducing hardware resource consumption while maintaining accuracy
Data Source
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Figure 3
Figure 4A~4B
AI summary
An apparatus comprising: a first register, for a pointer to a current bit position, updated by a clock cycle; a second register for a current Hamming Weight; a third register for a current index value; and adder logic configured to: determine an interim value based on a coefficient provided from a memory and the current index value, cause updating of the second and third registers comprising writing an updated index value based on the interim value to the third register.