AMR Reduction Circuit for Transmitter Signal Efficiency
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Solution Overview
Problem
Current communications transmitters, particularly those using quadrature-modulator-based systems, face inefficiencies in energy usage due to high peak-to-average ratio (PAR) signals from non-constant envelope modulation schemes, leading to reduced battery life in battery-powered devices and compliance issues with noise restriction standards.
Innovation Solution
The implementation of an adaptive hole blowing method in communications transmitters, which adjusts the average-to-minimum magnitude ratio (AMR) of signals by dynamically modifying baseband signals based on local minimum thresholds, reducing high-frequency content and bandwidth expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If non-constant envelope modulation schemes are used to achieve higher data rates, then productivity is improved, but use of energy by moving object deteriorates due to high peak-to-average ratio requiring power back-off
Solution Approach 1:
The patent applies preliminary action by modifying the baseband signal before modulation to reduce the average-to-minimum magnitude ratio. The hole blowing technique pre-processes the signal to eliminate deep fades and reduce dynamic range, allowing the power amplifier to operate more efficiently without requiring excessive power back-off, thus improving energy efficiency while maintaining high data rates
Solution Approach 2:
The patent changes the signal parameters by adjusting the average-to-minimum magnitude ratio through hole blowing. By modifying the baseband signal characteristics to reduce AMR, the system enables more efficient power amplifier operation, thereby improving energy efficiency without sacrificing the high data rate capability provided by non-constant envelope modulation schemes
2Productivity
If non-constant envelope modulation schemes are used, then productivity is improved, but object-generated harmful factors worsen due to increased adjacent channel leakage and receive band noise
Solution Approach 1:
The hole blowing technique performs preliminary signal processing to reduce the dynamic range of the baseband signal before modulation. By pre-modifying the signal to reduce AMR, the system minimizes the generation of adjacent channel leakage and receive band noise, allowing high data rate transmission without excessive harmful emissions
Solution Approach 2:
The patent changes the signal parameters by reducing the average-to-minimum magnitude ratio through hole blowing. This parameter modification suppresses the generation of adjacent channel leakage and receive band noise, enabling the system to achieve high data rates while complying with noise restriction standards
3Use of energy by moving object
If hole blowing is applied to reduce AMR, then use of energy is improved, but device complexity increases due to additional signal processing requirements
Solution Approach 1:
The patent extracts and removes the problematic deep fade portions from the baseband signal through hole blowing. By identifying and modifying only the specific signal portions that cause high AMR, the system achieves energy efficiency improvements without requiring complex overall signal processing architecture
Solution Approach 2:
The hole blowing technique applies local quality by selectively modifying only the portions of the baseband signal that exhibit deep fades or low magnitude. Rather than processing the entire signal uniformly, the system applies targeted modifications to specific signal segments, reducing computational complexity while maintaining energy efficiency benefits
4Manufacturing precision
If adaptive hole blowing with multiple thresholds is implemented, then manufacturing precision is improved for noise compliance, but device complexity increases
Solution Approach 1:
The patent applies parameter changes by implementing multiple magnitude thresholds for differentiating local minimum events. This enables precise control over signal modification levels to achieve accurate compliance with noise restriction standards, with each threshold level corresponding to specific regulatory requirements for different communication systems
Solution Approach 2:
The adaptive hole blowing mechanism employs dynamics by adjusting the threshold selection based on the current signal conditions and required noise compliance levels. The system dynamically chooses appropriate threshold levels to achieve precise noise compliance while managing complexity through adaptive rather than static threshold management
Data Source
AI summary
A communications transmitter configured to reduce the average-to-minimum magnitude ratio (AMR) of a communications signal includes a symbol mapper, a pulse-shaping filter, an AMR reduction circuit, and a modulator. The symbol mapper operates to generate a sequence of symbols from a binary-source data stream containing a message to be transmitted, and the pulse-shaping filter generates a baseband signal based on the sequence of symbols. The AMR reduction circuit is configured to compare a magnitude of a local minimum of samples of the baseband signal to various magnitude threshold levels, and to modify the baseband signal in one of two manners depending on the relationship of the magnitude of the local minimum and the various threshold levels. Finally, the modulator operates to modulate a carrier signal based on the modulation information contained in the modified baseband signal.