Filtrado de una señal discreta de la intensidad de campo eléctrico de la banda de frecuencia de 76 Mhz a 2686 Mhz durante un día en la Espoch utilizando la media móvil.

Abstract

The current degree work was aimed to filter the discrete signal of the electric field strength of the frequency band from 76 MHz to 2686 MHz using the previous moving average with n = 2. The temporal measurements of E ⃗ database were used obtained from the continuous monitoring of the day (Monday, August 15th, 2016) at ESPOCH using the NARDA SRM-3000 equipment. All the telecommunications services are committed to this frequency band, considering that it is all the radiation that a person receives while walking. The mean values of the intensity of E ⃗ vector of each period during the indicated day are made up of 240 points since the measurements were obtained every 6 minutes, obtaining a discrete intensity signal E ⃗. The described technique was used to filter this quite complex signal due to it is a variant in time. It was aimed to achieve an algorithm that meets the requirements for the correct smoothing of the resulting signal. The algorithm that allowed the signal filtering was programming with MATLAB software. The obtained result was a more understandable signal compared to the original signal, without distorting or getting lost in its initial signal. The smoothed signal will be used to determine the specific absorption rate (SAR) in future research. It was concluded that this technique is very simple, easily understood for the smoothing of discrete signals considering as a simple low-pass FIR filter (Finite Impulse Response). It is recommended not to exceed more than 30 passes of the moving average since when this limit is exceeded, the changes in the smoothing of the signal are not relevant.