Desarrollo de una interfaz para simulación de modulaciones digitales utilizando lenguaje de programación python

Abstract

In this project a software-based interface is developed to simulate a signal modulation system using the Python programming language, to which different steps are added to simulate the transmission and reception of the modulated signal, obtaining a telecommunication system composed of the following stages: conditioning of the signal to be modulated (in this case the signal is a vector of size N of random binary numbers), information coding, signal modulation, transmission in a channel (in this case white Gaussian noise channels with different Eb/No ratio are used), in reception a filter coupled to the demodulator, and finally a decoder. The reception, a filter coupled to the demodulator, and finally a decoder. The development of the project was done with the libraries: NummPy to perform the mathematical processes, SciPy and Commpy to calculate the model of the modulator and demodulator, also to implement filters and add the modulated signal to the white Gaussian noise channel. In addition, the WxPython library was used to create the user interface that allows selecting the modulation type between M-PSK, GMSK and M-QAM. Thus, within the menu of each modulation it is possible to vary the number of bits to transmit, the roll off factor for the filters, select the number of symbols of the modulation (M-PSK and M-QAM) and finally with the Matplotlib library the different graphs are plotted, such as the binary signal in transmission and reception, the modulated signal, the influence of the white Gaussian noise channel on the signal, filters, constellation diagrams in transmission and reception, the BER (Bit Error Rate) vs Eb/No (Energy per bit / noise power spectral density) plot, and the comparison of the binary information at the transmitter with the binary information at the receiver.