CFR Error Placement in Antenna Filter Stopbands
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Solution Overview
Problem
Existing Crest Factor Reduction (CFR) algorithms in radio transmission systems generate error components that limit peak power reduction, leading to increased distortion and power consumption, with error components often exceeding bandwidth limits and interfering with neighboring frequency bands.
Innovation Solution
The proposed solution involves a digital processing device that generates a digital transmission signal, converts it to an analog signal, amplifies it, and filters it using an antenna filter configured to pass specific frequencies and attenuate others, manipulating the frequency spectrum of error components to deposit them in stopbands, thereby reducing peak power and minimizing interference with neighboring bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If Crest Factor Reduction (CFR) algorithms are applied to reduce peak power in digital transmission signals, then power amplifier efficiency is improved and power consumption is reduced, but error components are generated that may exceed bandwidth limits and interfere with neighboring frequency bands
Solution Approach 1:
The patent converts the harmful error components generated by CFR algorithms into a beneficial solution by deliberately shaping their frequency spectrum to deposit them in stopbands. Instead of treating error components as unwanted byproducts to be minimized, the invention exploits them as a mechanism to improve power amplifier efficiency while maintaining spectral compliance through controlled frequency distribution.
Solution Approach 2:
The patent applies local quality by differentiating the treatment of error components across different frequency regions. Error components are selectively concentrated in stopbands where they are attenuated by the antenna filter, while passbands maintain clean signal quality. This localized frequency-domain management allows simultaneous optimization of power efficiency and spectral purity in different regions.
2Reliability
If error components are limited to the transmission band, then spectral compliance is maintained, but peak power reduction capability is restricted and distortion increases
Solution Approach 1:
The patent transitions from a one-dimensional constraint (limiting error components to the transmission band) to a two-dimensional solution by utilizing both frequency dimension (stopbands) and spatial dimension (frequency spectrum manipulation). This allows error components to be redistributed across the frequency spectrum, placing them in stopbands where they do not violate spectral compliance requirements while enabling greater peak power reduction.
3Power
If peak power is reduced in digital transmission signals, then power amplifier efficiency improves, but the signal quality may deteriorate due to increased distortion from error components
Solution Approach 1:
The patent introduces frequency spectrum manipulation as an intermediary mechanism between peak power reduction and signal quality maintenance. By controlling the frequency distribution of error components through spectral shaping, the invention mediates the trade-off between power efficiency and signal quality, allowing aggressive peak power reduction while keeping in-band error components minimal and out-of-band components contained in stopbands.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach significantly reduces CFR errors within the transmission band, allowing for lower peak power amplifiers with reduced power consumption and compliance with emission regulations, while maintaining signal quality and throughput.
Implementation Method 1
an antenna filter connected to the power amplifier and configured to filter the amplified analog transmission signal, wherein the antenna filter is configured to pass frequencies in at least one passband and to attenuate frequencies in at least one stopband
Implementation Method 2
a digital-to-analog converter connected to the digital processing device and configured to convert the digital transmission signal into an analog transmission signal
Data Source
Figure 1~2A
Figure 2B
Figure 3~6
AI summary
An apparatus is described which comprises a digital processing device configured to generate a digital transmission signal, a digital-to-analog converter connected to the digital processing device and configured to convert the digital transmission signal into an analog transmission signal, a power amplifier connected to the digital-to-analog converter and configured to amplify the analog transmission signal, and an antenna filter connected to the power amplifier and configured to filter the amplified analog transmission signal, wherein the antenna filter is configured to pass frequencies in at least one passband and to attenuate frequencies in at least one stopband, wherein the digital processing device is configured to perform: a process of reducing peak power in the digital transmission signal, wherein in this process error components having different frequencies are produced, and manipulating a frequency spectrum of the error components such that at least a part of the error components is deposited in the at least one stopband of the antenna filter.