Power Amplifier Supply Tracking for APT-ET Mode Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Power conservation in transceivers, particularly in mobile communication devices and base stations, is challenging due to inefficiencies in existing average power tracking (APT) and envelope tracking (ET) mechanisms, especially when handling LTE carrier aggregation signals with high frequency content and periodicity, which lead to power loss and undesired spurs.
Innovation Solution
A system that dynamically switches between APT and ET modes based on transmission parameters, using a threshold-based or weighted factor analysis to determine the most efficient mode for each transmission time slot, optimizing power consumption and linearity by adjusting the supply voltage to match the amplitude modulation of the RF signal, and employing a DC-DC converter to provide a variable supply voltage that tracks the RF envelope.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If envelope tracking (ET) mechanism is used to dynamically adjust supply voltage to track amplitude modulation signal, then power efficiency is improved, but device complexity increases due to requirement of fast DC-DC converter
Solution Approach 1:
The patent implements dynamic switching between APT and ET modes based on real-time analysis of transmission parameters. The system dynamically adjusts the supply voltage tracking strategy: using ET mode when signal characteristics favor power savings, and APT mode when simplicity and stability are prioritized. This dynamic adaptation resolves the contradiction by making the complex ET mechanism conditional rather than permanent.
Solution Approach 2:
The system changes operational parameters (mode selection between APT and ET) based on varying transmission conditions such as signal power level, modulation type, and bandwidth. By monitoring these parameters and adapting the voltage tracking approach accordingly, the system achieves optimal power efficiency without permanently incurring the complexity overhead of ET architecture.
2Device complexity
If average power tracking (APT) mechanism is used with fixed supply voltage during time slot, then device complexity is reduced, but power efficiency deteriorates due to inability to track amplitude modulation variations
Solution Approach 1:
The patent transforms the static APT mechanism into a dynamic hybrid system that can switch between APT and ET modes. The system continuously evaluates transmission parameters and dynamically selects the appropriate operating mode, thereby eliminating the need for permanently complex ET hardware while capturing power efficiency benefits when conditions are favorable.
Solution Approach 2:
The system performs self-analysis of transmission parameters and autonomously determines the optimal operating mode without requiring external control. The transceiver itself monitors its own operational state and switches between APT and ET modes based on real-time conditions, achieving improved power efficiency through self-directed mode selection while maintaining simple architecture.
3Use of energy by moving object
If envelope tracking is used for signals with high frequency content and periodicity such as LTE carrier aggregation, then power efficiency may improve, but undesired spurs are generated due to interaction with DC-DC converter characteristics
Solution Approach 1:
The patent implements a feedback mechanism that monitors transmission parameters including signal frequency content, periodicity, and power level. Based on this feedback, the system determines whether ET mode is appropriate or if APT mode should be used to avoid spur generation. This feedback-controlled mode selection resolves the contradiction by preventing ET operation under conditions that would generate harmful spurs.
Solution Approach 2:
The system performs preliminary analysis of transmission parameters before initiating ET mode operation. By evaluating signal characteristics in advance, the system prevents the generation of undesired spurs by avoiding ET mode when signal properties (high frequency content, specific periodicity patterns) are likely to interact problematically with DC-DC converter characteristics.
4Use of energy by moving object
If dynamic mode switching between APT and ET is implemented based on transmission parameters, then power efficiency is optimized across various scenarios, but control complexity increases
Solution Approach 1:
The transceiver performs self-analysis of its own transmission parameters and autonomously determines the optimal operating mode. The mode selection logic is integrated within the transceiver itself, eliminating the need for external controllers or complex centralized management. This self-directed approach optimizes power efficiency while keeping control complexity manageable by distributing the decision-making function.
Solution Approach 2:
The system implements mode switching based on a subset of available transmission parameters rather than analyzing all possible parameters. By selecting key parameters (such as signal power level, modulation type, and bandwidth) that have the most significant impact on power consumption, the system achieves effective power optimization without the control complexity that would result from comprehensive parameter analysis.
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 improves power efficiency and linearity in transceivers, reducing power consumption and minimizing losses, while maintaining performance across various power levels and transmission scenarios, including multi-cluster and carrier-aggregation cases.
Implementation Method 1
employing a DC-DC converter to provide a variable supply voltage that tracks the RF envelope
Data Source
AI summary
An apparatus of a transmitter and method are provided, the apparatus comprising a processor that calculates a supply voltage (SV) value (SVV) to provide as an SV for a power amplifier (PA) of the transmitter for transmissions during a transmission time slot (TS). When the SV<an envelope tracking (ET) threshold (ETT), then the processor configures the PA to transmit a signal in an average power tracking (APT) mode that maintains the SV at the SVV during the TS. When the SV≥ETT, and an APT condition is met, then the processor configures the PA to transmit the signal in the APT mode. When the SV≥ETT, and the APT condition is not met, then the processor transmits by an adjustment to the SVV to track an amplitude modulation envelope during the TS in an ET mode.