Power Amplifier Envelope Delay for Leakage Management
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Solution Overview
Problem
Existing power amplifiers in wireless communication systems face inefficiencies due to fixed supply voltages, leading to high current drain and excessive channel leakage, which complicates compliance with performance standards, especially in broadband applications like LTE, where optimizing power consumption and minimizing leakage are critical.
Innovation Solution
The solution involves introducing delays between envelope signals and data signals to intentionally cause asymmetrical leakage, allowing for reduced leakage in allocated channels and improved adjacent channel leakage ratio (ACLR) by strategically allocating resource blocks and using a power supply control circuit to manage the power amplifier's operation, thereby enhancing efficiency and reducing current drain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed supply voltage is used in power amplifier, then circuit complexity is reduced, but power efficiency deteriorates and current drain increases
Solution Approach 1:
The patent implements dynamic supply voltage adjustment by introducing a delay between the envelope signal and power supply modulation signal. This allows the power amplifier's supply voltage to be dynamically optimized for each symbol period, improving power efficiency while maintaining manageable circuit complexity through controlled adaptability.
2Use of energy by moving object
If power amplifier operates at saturation level, then power efficiency is improved, but signal quality and linearity deteriorate
Solution Approach 1:
The patent applies periodic supply voltage modulation synchronized with symbol periods, adjusting the supply voltage dynamically for each symbol. This periodic adjustment allows the power amplifier to operate efficiently at saturation while maintaining signal quality through timely voltage optimization for each transmission symbol.
Solution Approach 2:
The patent introduces a delay mechanism that prepares and adjusts the supply voltage before each symbol transmission. This preliminary voltage adjustment ensures the power amplifier is optimally configured for saturation operation at the start of each symbol period, maintaining both efficiency and signal integrity.
3Use of energy by moving object
If power supply modulation is used to vary supply voltage, then power efficiency is improved, but adjacent channel leakage increases
Solution Approach 1:
The patent applies supply voltage modulation selectively on a per-symbol basis rather than continuously. By controlling the timing and duration of voltage adjustments to align with symbol periods, the system achieves power efficiency improvements while limiting spectral regrowth and adjacent channel leakage through controlled, partial modulation action.
4Use of energy by moving object
If variable power supply is implemented, then power consumption is optimized, but circuit complexity and cost increase
Solution Approach 1:
The patent introduces a delay element as an intermediary component that synchronizes the power supply modulation signal with the envelope signal. This simple intermediary mechanism enables variable power supply operation for power optimization while maintaining circuit complexity at manageable levels through a straightforward timing adjustment approach.
Data Source
AI summary
A wireless communication system (400) for power amplification of an input signal includes a power amplifier (404) operable to amplify a data signal (405). An envelope generator 408 or detector is operable to determine an envelope signal (410) from the data signal. A tracking power supply or other power supply control circuit (409) is operable to control a supply voltage of the power amplifier with the envelope signal. An allocation manager (441) is operable to determine a resource block allocation within a channel for the data signal. A delay circuit (443) is operable to insert a delay (550) between the envelope signal and the data signal as a function of the resource block allocation within the channel, thereby intentionally causing unbalanced leakage about the resource block allocation. Increased leakage on one side of the allocation results in improved leakage on the other side.