Predistortion Coefficient Table Switching for ACPR Stability
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Solution Overview
Problem
In communication technology, inferior pre-distortion coefficients used in Digital Pre-Distortion (DPD) processing lead to interference with neighbor cells due to deteriorated Adjacent Channel Power Ratio (ACPR) of output signals, as real-time data collection cannot ensure coefficient availability and periodic training sequences disrupt service data.
Innovation Solution
A method and system that utilize a primary table with default pre-distortion coefficients and a standby table with updated coefficients, switching between them based on power data analysis, including Fast Fourier Transformation and ACPR calculations, to ensure superior pre-distortion processing and minimize interference with neighbor cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If real-time data collection is used to train pre-distortion coefficients, then coefficient availability is improved, but the reliability of the coefficient deteriorates because the collected data cannot ensure coefficient availability
Solution Approach 1:
The system performs preliminary action by collecting and evaluating signal data before switching coefficient tables. The controller continuously monitors signal quality metrics (ACPR, EVM) and pre-evaluates whether the standby table's coefficients meet quality thresholds before actual switching occurs, ensuring reliable coefficients are ready in advance.
Solution Approach 2:
The system implements feedback by continuously monitoring signal quality metrics (ACPR, EVM) and using this information to dynamically switch between primary and standby coefficient tables. The controller evaluates real-time signal characteristics and adjusts coefficient selection based on feedback, ensuring optimal performance under varying channel conditions.
2Measurement precision
If periodic training sequences are sent to train pre-distortion coefficients, then coefficient accuracy is improved, but service data transmission is interfered with
Solution Approach 1:
The system extracts the training function from periodic dedicated training sequences and integrates it into normal data transmission. By using real service data for coefficient training and evaluation, the system eliminates the need for separate training sequences, thereby avoiding interference with service data while maintaining coefficient accuracy.
Solution Approach 2:
The system applies multi-functionality by making the coefficient table serve dual purposes: it acts as both the operational coefficient storage and the training/evaluation medium. The same coefficient tables used for signal processing are continuously evaluated using real transmission data, eliminating the need for separate training sequences.
3Device complexity
If inferior pre-distortion coefficients are used, then device complexity is reduced, but ACPR deteriorates causing interference with neighbor cells
Solution Approach 1:
The system changes parameters by maintaining multiple coefficient tables with different characteristics (primary table with default coefficients, standby table with updated coefficients). The controller dynamically selects between tables based on signal quality parameters (ACPR, EVM), allowing the system to adapt to varying channel conditions without increasing hardware complexity.
Solution Approach 2:
The system introduces dynamics by making the coefficient selection adaptive rather than static. The controller continuously monitors signal quality and dynamically switches between coefficient tables based on real-time conditions, enabling the system to maintain optimal performance without complex real-time coefficient calculation capabilities.
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 allows for real-time updating of pre-distortion coefficients, reducing interference with neighbor cells by selecting the appropriate table based on power data, thereby maintaining optimal ACPR and minimizing signal deterioration.
Implementation Method 1
performing the Fast Fourier Transformation on the first signal, and determining the power data of the first signal together with the power parameters
Data Source
AI summary
The invention is a method and a system for updating pre-distortion coefficients, which is used to solve the problem of interference with neighbor cells due to the inferior pre-distortion coefficients. The method includes: presetting a primary table and a standby table, which store default and updated pre-distortion coefficients respectively; when a data source of a pre-distortion processor adopts the standby table, adopting the updated pre-distortion coefficients to perform parameter output processing to acquire pre-distortion parameters, and conveying the pre-distortion parameters and an input signal to the pre-distortion processor to process to acquire pre-distortion signals; conveying the pre-distortion signals through various signal processors to acquire a first signal, and determining the power data of the first signal; and based on the comparing result of the power data of the first signal and a setting range, there are different actions.