Analog Predistorter Core Module for PA Memory Distortion
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Solution Overview
Problem
Existing analog predistorter systems are ineffective in correcting distortion caused by power amplifiers with non-corresponding distortion characteristics, leading to suboptimal communication quality.
Innovation Solution
The proposed analog predistorter core module includes a radio frequency delay module, an envelope module, and a contact matrix module, which generate multiple radio frequency delay signals and envelope signals with different delays, allowing the contact matrix module to produce a predistortion signal that effectively offsets distortion by matching the power amplifier's characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional analog predistorter system is used, then the system structure is simple, but it cannot effectively correct distortion when the power amplifier has non-corresponding distortion characteristics
Solution Approach 1:
The predistorter is divided into multiple parallel channels, each processing signals with different delay characteristics. The radio frequency delay module creates multiple delayed versions of the input signal, and each channel processes these delayed signals independently before combining them. This segmentation allows the system to handle complex distortion characteristics by distributing the correction task across multiple specialized paths.
Solution Approach 2:
The system introduces adjustable delay elements that can be dynamically configured to match the memory effects of the power amplifier. The delay amounts in different channels can be adjusted to correspond to the specific distortion characteristics of the PA, making the predistorter adaptive to different operating conditions and amplifier characteristics.
2Reliability
If multiple delay channels are added to handle memory effects, then distortion correction capability is improved, but the device complexity increases
Solution Approach 1:
Each delay channel is designed with universal processing blocks that can handle multiple functions. The same envelope detector, predistortion coefficient application, and signal combination logic are reused across all channels, reducing the need for separate dedicated circuits for each channel and thereby limiting the increase in overall system complexity.
Solution Approach 2:
The system uses identical circuit implementations for each delay channel, copying the same functional blocks multiple times. This modular copying approach allows easy scaling to accommodate different numbers of channels while maintaining design consistency and simplifying the design process through repetition of proven functional units.
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 solution enables effective correction of distortion generated by power amplifiers with strong memory effects, improving communication quality by ensuring the output signal closely resembles the input signal.
Implementation Method 1
a radio frequency delay module, an envelope module, and a contact matrix module, where the contact matrix module is connected to both the radio frequency delay module and the envelope module; the radio frequency delay module is configured to receive a feed-forward radio frequency signal, generate multiple radio frequency delay signals with different delays according to the feed-forward radio frequency signal
Implementation Method 2
the envelope module is configured to receive the feed-forward radio frequency signal, perform envelope detection on the feed-forward radio frequency signal to obtain multiple envelope signals with different delays
Implementation Method 3
the contact matrix module is configured to receive each radio frequency delay signal, each envelope signal, and a predistortion coefficient from exterior, and generate a predistortion signal according to the predistortion coefficient, each radio frequency delay signal, and each envelope signal
Implementation Method 4
The PA amplifies a mixed signal obtained by mixing the predistortion signal and the master delay signal, to obtain a transmit signal
Data Source
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Figure 2-2
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AI summary
The present invention discloses an APD core module and an APD system and pertains to the communications field. The APD core module includes a radio frequency delay module, an envelope module, and a contact matrix module. The radio frequency delay module is configured to receive a feed-forward radio frequency signal, generate multiple radio frequency delay signals with different delays according to the feed-forward radio frequency signal, and output each radio frequency delay signal to the contact matrix module. The envelope module is configured to receive the £eed-forward radio frequency signal, perform envelope detection on the feed-forward radio frequency signal to obtain multiple envelope signals with different delays, and output each envelope signal to the contact matrix module. The contact matrix module is configured to receive each radio frequency delay signal, each envelope signal, and a predistortion coefficient from exterior, and generate a predistortion signal according to the predistortion coefficient, each radio frequency delay signal, and each envelope signal. According to the present invention, distortion generated by a PA can be effectively offset.