摘要无线通信系统的飞速发展，伴随着现代通信频段的日益拥挤，因而通信系统朝着追求更高频谱利用率的方向发展。为了提高频谱利用率，现代通信系统多采用非恒定包络调制方式，通常需要用功率回退的方式来达到系统的线性化要求，这又与功率放大器高效率的要求相悖。因此，功率放大器建模和线性化技术成为兼顾效率和频谱利用率的重要技术之一。25233
本文以宽带功率放大器的非线性特性为切入点，对功率放大器的行为建模进行研究，并拓展到数字预失真技术。主要开展以下工作：1.阐述功率放大器建模的基本理论，分析研究功放器的非线性特性的产生原因和影响。简要介绍了记忆效应。 2.讨论几种普通建模方法，分析各模型特点。 3.利用实测已有功放数据以数学方法进行功率放大器建模，仿真并验证模型的精确度。研究了矢量阈值分解技术，并利用分段记忆多项式建立一种新型的功放模型。 4.利用间接学习结构来建立预失真模型，通过前置预失真器来改善系统非线性，对预失真器的建模效果进行评估。
关键词 功率放大器 行为模型 记忆效应 非线性 预失真
毕业论文设计说明书外文摘要
Title Research on Modeling and Digital Predistortion Technique for Wideband RF Power Amplifier
Abstract
Since the wireless communication system develops rapidly, frequency resources are becoming increasingly scarce. People requires for more efficient use of frequency spectrum and achievements of greater power efficiency. The power amplifier plays a key role in the communication system, whose nonlinearity is the main source of
distortion. In order to make more efficient use of frequency spectrum, non-constant envelope modulations have been extensively applied in modern communication systems, which makes the RF amplifiers use power back-off to achieve the system’s linear requirements. Power amplifiers usually work in the saturated state, which will produce severe nonlinear distortion. To improve output power and efficiency, PA-model-technique and predistortion play a key role to resolve the conflict between efficiency and power efficiency.
This paper concentrates on the nonlinear characteristics 、behavioral models of the PA as well as digital predistortion. Mainly including:
1. The basic modeling theory and nonlinear characteristics are described and the memory effects are introduced.
2. Several basic models of the PA are discussed ,including their characteristics.
3. Using the mathematics methods to analyze the two kinds of models, the volterre- dynamic-deviation-reduction model and memory-polynomial model. A new piecewise Volterra model based on a vector threshold is introduced.
4. decomposition technique
5. Build the models of digital predistortion and evaluate the performance of the model.
Keywords power amplifier(PA) behavioral model memory effect nonlinearity predistortion
目 次
1 绪论 1
1.1 课题背景及意义 1
1.2 本文主要研究内容 2
2 射频功率放大器的非线性特性及线性化技术 3
2.1 射频功率放大器的非线性特性 3
2.1.1 谐波失真 3
2.1.2 互调失真 3
2.1.3 AM/AM和AM/PM变换 4
2.2 功率放大器的非线性评价指标 5
2.2.1 功率放大器非线性参数 5
2.2.2 ACPR 6
2.3 功率放大器的记忆效应 6
2.4 功率放大器的线性化技术 6 宽带射频功率放大器建模与预失真技术研究:http://www.youerw.com/tongxin/lunwen_18906.html