Adaptive PA Supply Control With Predistortion for Clipping-Free Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional wireless transmitters provide a fixed supply voltage to power amplifiers that is higher than necessary for most operating conditions, leading to inefficient power usage and potential clipping of output signals.
Innovation Solution
A communication system that adjusts the power supply for a power amplifier based on identified parameters such as target transmit power and characteristics of the baseband signal, using relationships stored in a look-up table to optimize supply voltage and current, and updates these relationships over time based on performance information collected during wireless transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed supply voltage higher than necessary is provided to the power amplifier, then the power amplifier can operate under worst-case conditions without clipping, but power consumption increases and power efficiency decreases
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed supply voltage to a dynamic supply voltage that changes over time based on instantaneous signal conditions. The supply voltage is adjusted in real-time according to the envelope of the modulated signal, allowing the power amplifier to receive only the necessary voltage for current operating conditions rather than always receiving the maximum voltage required for worst-case scenarios.
Solution Approach 2:
The patent changes the parameter of supply voltage from a constant fixed value to a time-varying parameter that adapts to signal conditions. By modifying the supply voltage parameter dynamically based on the signal envelope and operating conditions, the system achieves better power efficiency while maintaining reliability under varying load conditions.
2Device complexity
If a fixed supply voltage is provided to the power amplifier, then the circuit design is simple, but power efficiency is reduced and the power amplifier cannot adapt to varying operating conditions
Solution Approach 1:
The patent introduces dynamic control mechanisms that adjust the supply voltage based on real-time signal conditions. This involves adding control circuitry that monitors the signal envelope and modulates the supply voltage accordingly, transforming the static power supply into an adaptive system that improves power efficiency.
Solution Approach 2:
The patent implements feedback mechanisms where the signal envelope and operating conditions are continuously monitored and used to adjust the supply voltage. This closed-loop control ensures that the power amplifier receives the optimal supply voltage for current conditions, improving power efficiency while maintaining signal integrity.
3Use of energy by moving object
If the supply voltage is reduced to improve power efficiency, then power consumption decreases, but the power amplifier may clip the output signal under high-power conditions
Solution Approach 1:
The patent uses dynamic supply voltage adjustment where the voltage level is continuously adapted to match the instantaneous signal requirements. During high-power conditions, the supply voltage is increased to prevent clipping, while during low-power conditions, the voltage is reduced to improve efficiency. This dynamic adaptation resolves the contradiction between power efficiency and signal quality.
Solution Approach 2:
The patent changes the supply voltage parameter dynamically based on operating conditions and signal envelope characteristics. By adjusting this critical parameter in real-time, the system prevents signal clipping during high-power transmission while maintaining power efficiency during normal operating conditions.
4Use of energy by moving object
If different discrete power supply voltage levels are used for different output voltage ranges, then power efficiency is improved, but the control system complexity increases
Solution Approach 1:
The patent implements a dynamic voltage switching system that selects from multiple discrete supply voltage levels based on the current operating conditions and signal envelope. This dynamic selection process is controlled by a microcontroller or digital signal processor that monitors signal characteristics and adjusts the supply voltage accordingly, achieving power efficiency improvements while managing control complexity through software-based control.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
According to at least one aspect, a communication system is provided. The communication system includes a power amplifier configured to amplify an input signal to generate an amplified output signal and provide the amplified output signal to an antenna, a power supply coupled to the power amplifier and configured to provide power to the power amplifier based on a power supply control signal, and a controller coupled to the power supply. The controller is configured to identify a target transmit power level for transmission of a wireless signal, generate the power supply control signal based on the target transmit power level using information indicative of a relationship between the target transmit power level and a setting of the power supply, generate performance information indicative of a characteristic of the communication system when the wireless signal is transmitted, and update the information indicative of the relationship using the performance information.