CFR Error Shaping Into Antenna Filter Stopbands
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Solution Overview
Problem
Existing Crest Factor Reduction (CFR) algorithms in radio transmission systems produce error components that limit peak power reduction, leading to inefficiencies in power amplifiers and increased Signal-to-Noise Ratio (SNR) distortion, while also violating spectral emission masks due to the inability to effectively distribute error components outside the transmission band.
Innovation Solution
A method and apparatus that utilize a digital processing device to generate a digital transmission signal, convert it to an analog signal, and amplify it using a power amplifier, while an antenna filter attenuates frequencies in stopbands, manipulating the frequency spectrum of error components to deposit them in the stopband, thereby reducing peak power and minimizing in-band distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If CFR algorithms are applied to reduce peak power in digital transmission signals, then power amplifier efficiency is improved, but error components are produced that violate spectral emission masks and increase SNR distortion
Solution Approach 1:
The patent extracts error components generated by CFR algorithms and relocates them to stopband frequencies where they are attenuated by the antenna filter. This separation removes harmful error components from the transmission band while preserving the peak power reduction benefits in the passband.
Solution Approach 2:
The patent converts harmful error components that would normally degrade signal quality into a beneficial solution by deliberately placing them in stopband frequencies. The antenna filter then attenuates these error components, effectively using the filter's stopband characteristic to eliminate the harmful effects of CFR-generated errors.
2Reliability
If error components are limited to the transmission band, then spectral emission mask compliance is maintained, but peak power reduction capability is limited and power amplifier efficiency decreases
Solution Approach 1:
The patent extends the frequency domain from a single transmission band to multiple dimensions including passband and stopband frequencies. By utilizing stopband frequencies as an additional dimension for error component placement, the system achieves both spectral compliance in the passband and improved peak power reduction capability.
Solution Approach 2:
The antenna filter acts as an intermediary that allows error components to exist in stopband frequencies while preventing them from violating spectral emission masks in the transmission band. The filter mediates between the CFR algorithm's error generation and the spectral compliance requirement.
3Use of energy by moving object
If peak power is reduced in digital transmission signals, then power consumption is lowered, but error components increase SNR distortion and degrade signal quality
Solution Approach 1:
The patent extracts error components that degrade signal quality and relocates them to stopband frequencies where the antenna filter attenuates them. This extraction removes the harmful impact of error components on in-band signal quality while maintaining the power consumption benefits of peak power reduction.
Solution Approach 2:
The patent converts error components that would normally degrade signal quality into a beneficial element by placing them in stopband frequencies. The antenna filter's attenuation of these error components transforms what would be harmful SNR distortion into an acceptable out-of-band emission that does not affect in-band signal quality.
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 error within the transmission band, allowing for lower peak power requirements in power amplifiers, reduced power consumption, and compliance with spectral emission masks by depositing error components outside the transmission band, where they are attenuated by the antenna filter.
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
Data Source
AI summary
An apparatus 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, and a power amplifier connected to the digital-to-analog converter and configured to amplify the analog transmission signal. An antenna filter is connected to the power amplifier and configured to filter the amplified analog transmission signal; the antenna filter is configured to pass frequencies in at least one passband and to attenuate frequencies in at least one stopband. The digital processing device is configured to perform a process of reducing peak power in the digital transmission signal; in this process error components having different frequencies are produced. A frequency spectrum of the error components is manipulated such that a part of the error components is deposited in the stopband of the antenna filter.