DPD Feedback Control for Power Amplifier Nonlinearity
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Solution Overview
Problem
Nonlinear characteristics of power amplifiers in wireless communication systems cause distortion, leading to increased bit error rates, spectral interference, and reduced data transmission rates, particularly in OFDM and OFDMA techniques.
Innovation Solution
A device with a transmission path that includes a DPD conversion module and a power amplifier, coupled with a feedback path to generate a feedback signal, allowing the DPD control module to adjust the pre-distortion processing strategy based on amplitude and phase differences, thereby counteracting nonlinear characteristics and improving linearity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If power amplifiers are used to amplify transmission signals, then transmission power is increased, but nonlinear distortion is introduced
Solution Approach 1:
The patent applies pre-distortion processing to the transmission signal before it enters the power amplifier. The DPD conversion module generates a pre-distorted signal that compensates for the expected nonlinear distortion of the power amplifier, so that when the signal passes through the amplifier, the overall distortion is minimized. This preliminary action counteracts the harmful nonlinear effect before it can degrade the signal quality.
Solution Approach 2:
The patent implements a feedback mechanism where the output of the power amplifier is fed back through a feedback path to the DPD conversion module. The feedback signal is used to adjust and update the pre-distortion processing strategy in real-time, allowing the system to adapt to changes in the power amplifier's nonlinear characteristics and maintain optimal signal quality.
2Stability of the object's composition
If pre-distortion processing is applied to compensate for power amplifier nonlinearity, then linearity is improved, but device complexity increases
Solution Approach 1:
The DPD conversion module performs self-adjustment using the feedback signal from the power amplifier output. The system automatically updates its pre-distortion parameters based on the actual amplifier behavior, eliminating the need for external manual calibration or complex control systems. This self-service capability reduces operational complexity while maintaining high signal linearity.
3Device complexity
If traditional power amplification is used without pre-distortion, then device complexity is reduced, but bit error rate increases
Solution Approach 1:
The patent applies pre-distortion processing to the transmission signal before it enters the power amplifier. The DPD conversion module generates a pre-distorted signal that compensates for the expected nonlinear distortion of the power amplifier, so that when the signal passes through the amplifier, the overall distortion is minimized. This preliminary action counteracts the harmful nonlinear effect before it can degrade the signal quality.
Solution Approach 2:
The patent implements a feedback mechanism where the output of the power amplifier is fed back through a feedback path to the DPD conversion module. The feedback signal is used to adjust and update the pre-distortion processing strategy in real-time, allowing the system to adapt to changes in the power amplifier's nonlinear characteristics and maintain optimal signal quality.
Data Source
AI summary
In certain aspects, a device for wireless transmission includes a transmission path, a feedback path, and a DPD control module. The transmission path includes a digital pre-distortion (DPD) conversion module configured to perform pre-distortion processing on an amplitude and a phase of a transmission signal based on a pre-distortion processing strategy. The transmission path further includes a power amplifier coupled to a downstream of the DPD conversion module and configured to amplify a power of the transmission signal. The feedback path is coupled to the transmission path at the downstream of the power amplifier and configured to generate a feedback signal. The feedback path includes a static gain compensation module configured to be activated during an initial time period of each frame to track and update a static gain for the feedback signal and configured to hold the static gain after the initial time period of each frame. The DPD control module is coupled to the feedback path and the DPD conversion module and configured to adjust the pre-distortion processing strategy based on an amplitude difference and a phase difference between the transmission signal and the feedback signal.