Digital predistortion by using GPIB-controlled instrumentation
Tutor / director / evaluatorMontoro López, Gabriel
Document typeMaster thesis
Rights accessOpen Access
A digital predistortion using real equipment, holding it with new software, is here presented. The Vector Signal Analyzer (VSA) –by Agilent– is a new software which allows to the user complete functionalities for the study of real signals. This software consists basically in a Spectrum Analyzer, regarding its performance, but increasing functionalities and commodity. With the VSA software one can have a complete control of an overall communication system, taking advantage of its capacity to share data with other applications. By this way, data information of the signal received on a Spectrum Analyzer can be obtained and studied. In this study is showed how the VSA allows taking data in different modes. Besides, using the COM API language, it is possible to control the VSA with other softwares. Using this performance, and combining it with GPIB (General Purpose Interface Bus), the complete management of the whole system is achieved from Matlab. The GPIB allows interconnecting both Signal Generator and Spectrum Analyzer devices with the PC. Once this connection is reached and all the parameters are well specified, the main goal of this Master Thesis is to turn the VSA software transparent to the user. The final scenario is to send a signal from Matlab and taking it –when the signal has passed across a power amplifier (PA)– again from Matlab (by means of the VSA software, but making it invisible to the user). In order to prove the correct performance of the system implementation, a digital predistortion is employed. Thus, once the digital predistortion is done, the performance of the overall system should increase. This is because the nonlinearities due to the PA should be solved. Herein, problems solved, VSA parameters adjustments, Matlab code program and main results of the digital predistortion, having in mind its future implementation in a FPGA, are presented.
Se trata de implementar un predistorsionador adaptativo para la linealización de amplificadores de radiofrecuencia. El montaje incluirá: - pc con tarjeta controladora GPIB - amplificador de radiofrecuencia - analizador de espectros - generador de RF de onda programable