PAPR Reduction in MIMO-OFDM via Dynamic Signal Selection
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Solution Overview
Problem
Current wireless communication systems face challenges in reducing the peak-to-average-power-ratio (PAPR) of aggregate waveforms, particularly in MIMO-OFDM systems, which leads to inefficiencies in power amplifiers and increased costs due to high PAPR, causing signal distortion and reduced spectral efficiency.
Innovation Solution
A method that generates a next generation population of data points using fitness values to optimize indexes for reducing PAPR, by evaluating initial populations and applying genetic algorithms or fitness functions to produce next generation indexes that construct aggregate waveforms with lower PAPR, ensuring compliance with regulatory emission criteria.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multi-carrier OFDM encoding is used to increase data transmission rate, then throughput is improved, but peak-to-average power ratio increases causing signal distortion
Solution Approach 1:
The patent applies dynamic signal selection and combination techniques where multiple candidate signals are generated with different phase rotations and time shifts, then dynamically selected and combined to achieve low PAPR while maintaining high data transmission rates through adaptive signal processing
Solution Approach 2:
The patent changes signal parameters by applying different phase rotations and time shifts to candidate signals, and by selecting optimal combinations of signals with varying characteristics to reduce PAPR while preserving throughput
2Productivity
If multiple transmission antennas are used to improve spectral efficiency, then throughput increases, but PAPR of aggregate waveforms increases causing power amplifier inefficiency
Solution Approach 1:
The patent employs dynamic signal combination techniques across multiple transmit antennas, where candidate signals are generated with different phase rotations and time shifts, then adaptively selected and combined to achieve low aggregate PAPR while maintaining high spectral efficiency through MIMO processing
Solution Approach 2:
The patent transforms the aggregate waveform characteristics by applying different phase rotations and time shifts to signals from multiple antennas, and by selecting optimal signal combinations to reduce the overall PAPR of the aggregated waveform, thereby improving power amplifier efficiency
3Productivity
If high-order QAM modulation is used to increase data rate, then throughput is improved, but signal distortion increases due to high PAPR
Solution Approach 1:
The patent uses dynamic signal selection and combination methods that adaptively choose and combine candidate signals with different phase rotations and time shifts to maintain low PAPR, enabling the use of high-order QAM modulation without significant signal distortion while preserving high throughput
Data Source
AI summary
A method and system uses a constrained set of indexed samples to identify a next generation population of samples that exhibits a more desirable signal characteristic. The invention generates an intermediate set of indexed samples which are subjected to a fitness function and next generation calculations to produce next generation indexes for the next population of samples. The next generation indexes population of samples is further constrained over initial indexes for generating a more desirable signal characteristic. In an example, the PAPR for all samples of the population are reduced.