Indoor positioning systems based on visible light communication (VLC) using white light-emitting diodes (WLEDs) have been widely studied in the literature. In this paper, we present an indoor visible-light positioning (VLP) system based on red–green–blue (RGB) LEDs and a frequency division multiplexing (FDM) scheme. This system combines the functions of an FDM scheme at the transmitters (RGB LEDs) and a received signal strength (RSS) technique to estimate the receiver position. The contribution of this work is two-fold. First, a new VLP system with RGB LEDs is proposed for a multi-cell network. Here, the RGB LEDs allow the exploitation of the chromatic space to transmit the VLP information. In addition, the VLC receiver leverages the responsivity of a single photodiode for estimating the FDM signals in RGB lighting channels. A second contribution is the derivation of an expression to calculate the optical power received by the photodiode for each incident RGB light. To this end, we consider a VLC channel model that includes both line-of-sight (LOS) and non-line-of-sight (NLOS) components. The fast Fourier transform (FFT) estimates the powers and frequencies of the received FDM signal. The receiver uses these optical signal powers in the RSS-based localization application to calculate the Euclidean distances and the frequencies for the RGB LED position. Subsequently, the receiver’s location is estimated using the Euclidean distances and RGB LED positions via a trilateration algorithm. Finally, Monte Carlo simulations are performed to evaluate the error performance of the proposed VLP system in a multi-cell scenario. The results show a high positioning accuracy performance for different color points. The average positioning error for all chromatic points was less than 2.2 cm. These results suggest that the analyzed VLP system could be used in application scenarios where white light balance or luminaire color planning are also the goals.

Las Tecnologías de la Información y la Comunicación (TIC) han sido clave para que la enseñanza en línea ingresara con tal ímpetu en el mundo pedagógico que modificara el paradigma educativo. La oferta y demanda de cursos en línea se ha incrementado fuertemente los últimos años debido principalmente a dos parámetros: su menor costo con respecto a cursos tradicionales, y la necesidad de distanciamiento social en tiempos de contingencia. Sin embargo, poco se sabe aún sobre la deseada equivalencia en la eficacia académica entre la opción en línea y la presencial. En este trabajo se comparan ambas modalidades a través de los resultados obtenidos en los cursos de ingreso presencial y en línea dados a aspirantes al programa de la Licenciatura Ingeniería en Computación de la Universidad Autónoma de Zacatecas. Los cursos fueron diseñados de manera que se minimizaran las diferencias entre ellos, siendo la variable clave la modalidad en línea o presencial. El análisis estadístico no muestra diferencias significativas, por lo que se concluye que ambas modalidades son equivalentes para este estudio de caso.