OFDM Power Amplifier Voltage Control via EVM Segmentation
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Solution Overview
Problem
Existing power control methods for OFDM systems treat all frequency bands uniformly, failing to account for differing modulation precision requirements of signals from users at different distances, leading to suboptimal performance.
Innovation Solution
A power control method that dynamically adjusts error vector magnitude (EVM) parameters and peak-to-average power ratio (PAPR) for near-end, mid-range, and far-end users, allowing for distinct processing and voltage control of power amplifiers to balance total power, EVM, and efficiency across the system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If same processing is performed on signals at an entire frequency band, then device complexity is reduced, but manufacturing precision of modulation precision requirements deteriorates
Solution Approach 1:
The frequency band is segmented into multiple sub-bands, and different processing strategies are applied to each sub-band based on the modulation precision requirements of signals in that band. This allows the system to handle different user signals with appropriate precision while avoiding the complexity of processing every signal individually.
Solution Approach 2:
Different processing parameters and power control strategies are applied to different sub-bands according to their specific requirements. Near-end users receive different processing than far-end users, optimizing modulation precision for each local condition rather than using a uniform approach across the entire frequency band.
2Manufacturing precision
If different processing is performed on signals of different orders, then manufacturing precision of modulation precision is improved, but device complexity increases
Solution Approach 1:
The system segments users into different categories (near-end users, far-end users, mid-range users) and applies different processing strategies to each category. This reduces the complexity compared to individual processing while still providing differentiated treatment to meet various modulation precision requirements.
Solution Approach 2:
The system changes processing parameters such as power control settings and PAPR reduction levels according to user type and distance. By adjusting these parameters based on user categories rather than individual users, the system achieves differentiated processing with controlled complexity.
3Power
If power amplifier supply voltage is increased, then power output is improved, but use of energy deteriorates
Solution Approach 1:
The power amplifier supply voltage is dynamically adjusted based on the current transmission requirements and user distribution. Rather than maintaining a fixed high voltage, the system adapts the voltage level to match the actual power needs, improving energy efficiency while maintaining adequate output power when required.
Solution Approach 2:
The system changes the power amplifier operating parameters including supply voltage based on real-time conditions such as total power requirements and EVM constraints. This allows the power amplifier to operate at optimal efficiency points while still meeting transmission power requirements.
4Use of energy by moving object
If PAPR reduction processing is applied, then power amplifier efficiency is improved, but manufacturing precision of EVM deteriorates
Solution Approach 1:
Different PAPR reduction processing levels are applied to different sub-bands and user types. Instead of applying uniform PAPR reduction to all signals, the system tailors the processing intensity to local requirements, preserving EVM precision for users who need it while still achieving PAPR reduction for overall efficiency improvement.
Solution Approach 2:
The system applies PAPR reduction processing selectively rather than universally. By applying partial processing to specific sub-bands or user signals where it is most beneficial, the system achieves sufficient power amplifier efficiency improvement without excessively degrading EVM precision across all signals.
Data Source
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AI summary
The present invention relates to a power control method and apparatus, where the method includes: respectively determining, by a base station, error vector magnitude EVM indicator adjustment parameters of n terminals according to terminal types of the n terminals that are currently scheduled; processing, according to the EVM indicator adjustment parameters of the n terminals, to-be-transmitted signals of the n terminals to obtain an output signal, and determining a change of total power of the output signal relative to the to-be-transmitted signals; and dynamically controlling a supply voltage of a power amplifier according to the change of the total power of the output signal relative to the to-be-transmitted signals. According to the power control method and apparatus provided in embodiments of the present invention, different processing is performed on signals of different terminals, so that a balance among total power, EVM, and power amplifier efficiency in an OFDM system is considered, and system performance of the OFDM system is improved.