Adaptive linearization of power amplifiers in digital radio systems
Adaptive linearization of power amplifiers in digital radio systems
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数字无线电系统中功率放大器的自适应线性化
DOI：
10.1002/j.1538-7305.1983.tb03113.x
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
J. Salz
中科院分区：
文献类型：
--
作者：
A. Saleh;J. Salz
高频功率放大器在饱和状态下工作效率最高，即在其输入/输出特性的非线性范围内。这种现象传统上要求使用恒定包络调制方法进行数据传输，从而导致圆形信号星座。这种方法固有地限制了数字无线电中允许的数据速率。本文提出了一种在不牺牲放大器功率效率的情况下解决这一问题的方法。描述和分析了一种自适应线性化电路，它可以自动补偿放大器的非线性，从而使传输多电平正交幅度调制信号成为可能，而不会引起不可容忍的星座失真。该线性化器利用实时的、数据导向的递归算法来预失真信号星座。我们的分析和计算机仿真表明，该算法是稳健的，并且从盲区开始就能快速收敛。此外，信号星座和平均发射功率都可以通过软件进行更改。
High-frequency power amplifiers operate most efficiently at saturation, i.e., in the nonlinear range of their input/output characteristics. This phenomenon has traditionally dictated the use of constant envelope modulation methods for data transmission, resulting in circular signal constellations. This approach has inherently limited the admissible data rates in digital radio. In this paper we present a method for solving this problem without sacrificing amplifier power efficiency. We describe and analyze an adaptive linearizer that can automatically compensate for amplifier nonlinearity and thus make it possible to transmit multilevel quadrature amplitude modulated signals without incurring intolerable constellation distortions. The linearizer utilizes a real-time, data-directed, recursive algorithm for predistorting the signal constellation. Our analysis and computer simulations indicate that the algorithm is robust and converges rapidly from a blind start. Furthermore, the signal constellation and the average transmitted power can both be changed through software.