Multi-Band Digital Pre-Distortion for Intermodulation Mitigation
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Solution Overview
Problem
In wireless communication systems, power amplifiers introduce nonlinearity, leading to intermodulation interference between frequency bands, which is difficult to mitigate, especially when bands are close together, affecting the performance of multi-band operations.
Innovation Solution
The implementation of multiple digital pre-distortion engines with finite impulse response filters and correlation matrixes to pre-distort signals, mitigating self-interference by determining and combining pre-distorted signals to minimize nonlinear effects across multiple frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If power amplifiers are used to amplify signals in multi-band operations, then signal transmission capability is improved, but intermodulation interference increases due to nonlinearity
Solution Approach 1:
The system performs pre-distortion of signals before amplification by power amplifiers. Multiple digital pre-distortion engines pre-process the signals to anticipate and compensate for the nonlinear effects that will occur during amplification, thereby reducing intermodulation interference before it is generated
Solution Approach 2:
The system uses correlation matrixes to analyze and utilize the characteristics of self-interference and intermodulation products. By determining correlation matrixes between different frequency bands and applying them in the pre-distortion process, the system converts the harmful nonlinear effects into predictable patterns that can be compensated for, turning the harmful intermodulation into a controllable parameter
2Object-generated harmful factors
If multiple digital pre-distortion engines are implemented to mitigate interference, then intermodulation interference is reduced, but device complexity increases
Solution Approach 1:
The system divides the pre-distortion function into multiple separate digital pre-distortion engines, each responsible for specific frequency bands or carriers. This segmentation allows independent optimization of each engine and enables modular implementation, managing complexity through functional decomposition
Solution Approach 2:
The system employs correlation matrixes that can be applied across multiple frequency bands and carriers universally. The same mathematical framework and processing approach are used for different bands, allowing the system to handle multi-band operations with a unified methodology rather than requiring completely separate solutions for each band
Data Source
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AI summary
A method comprising determining a plurality of digital pre-distortion engines, determining signals for the pre-distortion engines, determining terms for a matrix and filter the matrix, based on the filtered matrix, determining correlation matrixes, obtaining pre-distorted signals from the digital pre-distortion engines, wherein the pre-distorted signals are pre-distorted based on the determined correlation matrixes, and combining the pre-distorted signals to a combined pre-distorted signal.