Multidimensional QAM Signal Modulation Reducing Circuit Complexity
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Solution Overview
Problem
Ultra-multilevel QAM systems require high-capacity circuits for LDPC codes, leading to increased costs and power consumption due to the need for large-scale circuits for error correction.
Innovation Solution
Implementing a signal modulation apparatus that configures two-dimensional QAM in a multidimensional manner using multiple time slots, combining constellations of different QAM levels to reduce the number of signal points and average power, thereby reducing costs and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LDPC codes with high correction capability are applied to ultra-multilevel QAM, then error correction performance is improved, but circuit scale increases leading to higher costs and power consumption
Solution Approach 1:
The patent changes the modulation parameter from conventional 2D-QAM to multidimensional QAM (e.g., 4D-QAM), transforming the signal constellation structure. This parameter change allows achieving the same or better error correction performance with simpler coding schemes, thereby reducing circuit complexity while maintaining reliability
Solution Approach 2:
The patent introduces a new dimension to the QAM modulation by configuring two-dimensional QAM in a multidimensional manner using multiple consecutive time slots. This dimensional expansion enables more efficient signal packing and reduces the need for complex error correction circuits
2Device complexity
If multidimensional QAM with combination of constellations is used, then circuit complexity is reduced, but signal transmission performance may deteriorate
Solution Approach 1:
The patent segments the multidimensional signal constellation into multiple two-dimensional QAM constellations that are configured using multiple consecutive time slots. This segmentation approach allows the system to achieve multidimensional modulation benefits while maintaining the simplicity of 2D-QAM processing, thus preserving signal transmission performance with reduced circuit complexity
Solution Approach 2:
The patent employs periodic action by using multiple consecutive time slots to configure the multidimensional QAM signal. The signal points are transmitted in a periodic pattern across time slots, which maintains signal integrity and transmission performance while enabling simpler circuit implementation
Data Source
AI summary
Provided is a signal modulation apparatus configured to modulate an input signal into a multidimensional QAM signal using multidimensional QAM, in which Multidimensional QAM is QAM in which two-dimensional QAM is configured in a multidimensional manner using a plurality of consecutive time slots, a constellation for multidimensional QAM is part of a combination of a constellation of first two-dimensional QAM, and a constellation of second two-dimensional QAM.