Desarrollo de un simulador con interfaz gráfica de las técnicas OMA (CDMA, OFDMA) y NOMA (SCMA, OPDMA) para el laboratorio de comunicaciones de la FIE.

Abstract

The objective of this work was to develop a graphical interface simulator for orthogonal (CDMA, OFDMA), and non-orthogonal (SCMA, OPDMA) multiple access techniques, by analyzing its operation in order to program Matlab the stages of transmission and reception on AWGN, Rice and Rayleigh channels. Due to the robustness of the Matlab programming language, the scripts containing the lines of code necessary to carry out the simulation of the techniques and the graphical interface were developed. In the stages of transmission and reception of the techniques, the processing of the signals was carried out based on their operating principles. Wireless channels were increased with native software functions and mathematical calculation of channel gain. With a repetitive loop, the calculation of the bit error rate (BER) was performed as a function of the Signal to Noise Ratio (SNR). For the analysis and validation of the results obtained, simulations were carried out configuring input parameters in order to compare with results presented in scientific articles, resulting in a significant similarity with the reference article where the difference of less than 1 dB in the requirement was obtained of SNR in CDMA, 3 dB in OFDMA, 2.9 in SCMA and 3.2 in OPDMA, however, in the fading channels the curves differ in all techniques. It was concluded that the differences presented in the results obtained are due to the methodology applied in this work, however, the similarities in some techniques provide a high level of reliability for later implementation. It is recommended to implement the coding stages for error correction in the transmitter and decoder in the receiver to analyze the impact on the BER.