Digital Pre-Distortion Circuit With Adaptive Coefficient Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current digital pre-distortion (DPD) systems fail to meet the requirements of high-efficiency, wide-bandwidth, low-power consumption, and high-integration power amplifiers due to difficulties in quickly adapting to changing conditions such as bandwidth, temperature, and frequency, leading to suboptimal communication quality and increased power consumption.
Innovation Solution
A DPD circuit and method that determines and adjusts coefficients based on multiple features of an input signal, including amplitude, in-phase component, quadrature component, bandwidth, temperature, frequency, and modulation format, to generate a linear and undistorted output signal, using look-up tables and index tables to store pre-calculated coefficients, and includes preprocessing and solution modules to align signals and adapt coefficients in real-time when errors exceed thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a current DPD system is used, then the power amplifier can operate, but it cannot quickly adapt to changing conditions (bandwidth, temperature, frequency), resulting in suboptimal communication quality and increased power consumption
Solution Approach 1:
The patent implements dynamic adaptation by introducing multiple DPD coefficient sets corresponding to different operating conditions (bandwidths, temperatures, frequencies). The system dynamically selects and switches between these pre-calculated coefficient sets based on real-time operating parameters, enabling quick adaptation without complex real-time calculations. This resolves the contradiction by making the DPD system flexible and responsive to changing conditions while maintaining reliable communication quality.
Solution Approach 2:
The patent pre-calculates and stores multiple DPD coefficient sets for different operating conditions before actual operation. When the power amplifier operates, the system directly selects from these pre-prepared coefficients based on current conditions, avoiding the need for time-consuming real-time optimization calculations. This preliminary preparation enables rapid adaptation while ensuring communication quality through optimized pre-computed parameters.
2Adaptability or versatility
If a current DPD system is used, then the power amplifier can operate, but power consumption increases due to inability to adapt efficiently
Solution Approach 1:
The patent pre-calculates DPD coefficients for various operating conditions and stores them in lookup tables. During operation, the system simply retrieves the appropriate pre-computed coefficients based on current bandwidth, temperature, and frequency conditions, avoiding energy-intensive real-time optimization algorithms. This preliminary computation significantly reduces power consumption while maintaining adaptability to changing conditions.
Solution Approach 2:
The patent replaces complex real-time iterative optimization mechanisms with a simpler lookup and selection mechanism. Instead of performing continuous mathematical optimization that consumes significant computational power, the system substitutes this with direct table lookup based on operating parameters, dramatically reducing power consumption while preserving adaptability.
3Device complexity
If DPD coefficients are not adjusted for different conditions, then the system is simpler, but the output signal becomes non-linear and distorted
Solution Approach 1:
The patent segments the DPD coefficient space into multiple discrete sets, each optimized for specific operating conditions (different bandwidths, temperatures, frequencies). Instead of using a single complex adaptive system, the patent divides the problem into manageable segments that can be independently selected based on current conditions. This segmentation maintains signal linearity through condition-specific optimization while keeping the overall system structure relatively simple.
Solution Approach 2:
The patent changes the operating parameters of the DPD system by selecting different coefficient sets based on measured operating conditions. When bandwidth, temperature, or frequency changes, the system switches to the corresponding coefficient set optimized for those parameters. This parameter-based selection ensures signal linearity across different operating points without requiring a complex continuously-adaptive system.
Data Source
AI summary
A digital pre-distortion (DPD) circuit includes a DPD and a power amplifier (PA). The DPD module is configured to: obtain features of a first input signal, determine a first coefficient and a second coefficient based on the features of the first input signal, generate a second signal based on the first input signal and the first coefficient, generate a first output signal based on the second signal and the second coefficient, and input the first output signal to the power amplifier. The PA is configured to amplify the first output signal to generate a second output signal.