To Realize The Linearization Technology Of Power Amplifier

With the rapid development of electronic technology, the increasing number of available channels in a limited frequency for communication system, the utilization of spectrum is getting higher and higher, This own to the application of linear modulation pattern. The biggest advantage of linear modulation pattern is to improve the transmission efficiency and spectrum utilization, but it requires the system to retain good linearity, otherwise the modulated signal will produce intermodulation distortion, spread spectrum and adjacent channel interference, thus affecting the signal transmission and the quality of communication. In general, the main component influencing the linearity of RF system is power amplifier, its effect on the whole system is very important, so the study of its linearization technique is significant.This paper mainly discusses the linearization technology of power amplifier, firstly, analyzed the nonlinear problem existed in digital wireless communication system, summarized the status of this research. Then introduced the characteristic of the power amplifier, analyzed the influence of nonlinearity on the electronic communication system. Then introduced the commonly used model of the power amplifier, according to the extraction and modeling method of nonlinear characteristic of power amplifier, using the measured data to establish amplifier behavior model, and proposed amplifier testing system and method based on ADS interconnection platform; the fourth chapter mainly studied the non-memory-amplifier pre-distortion techniques based on look-up table, simulated in Matlab, and the simulation results show that the algorithm of polar coordinates lookup table can improve the nonlinear distortion of the amplifier, effectively inhibit the spread spectrum band, reducing adjacent channel interference. Constructed the verification platform based on the digital predistortion program, it used to quickly verify the digital predistortion method or algorithm. Finally, based on the physical experimental platform, it made a pre-distortion test of single-carrier WCDMA signal, the predistortion works well.