Diseño de un sistema de emergencia basado en radio cognitiva para transmitir mensajes de emergencia en las bandas de radio AM y FM

Abstract

In Colombia, in a period of 4 decades, approximately 28,000 disaster events have been recorded, including fires, floods, earthquakes, among others. According to data from the Ministry of Finance, 60% of these events have occurred since the 1990s. Currently Colombia does not have the necessary implements to have an early communication of disasters and due to the efforts of the national government it can be seen that disasters are not attended in a timely manner and there is a lack of implements that help to make an early communication of the event and thus be able to alert people of the imminent risk, this because mostly those responsible for giving alerts are the local government entities and these do not have the personnel available to provide alerts at the time they are required. In view of these aspects and in order to provide an emergency communication system to the people involved (groups that support in emergency situations), a tool was designed that allows a unidirectional transmission through the use of RTL-SDR2832U devices as receiver and the USRP N210 as transmitter, using the free GNU Radio software for the transmission and reception blocks, and with this implement an integration of the same for the transmission of messages through AM and FM modulations. The implementation of the cognitive radio system leads to a transmission of emergency messages in AM and FM modulation on commercial bands and free bands as required, in turn this system is capable of transmitting different emergency messages which adds an extra functionality to provide diversity of emergency audios for use as required by the eventuality. After implementing the emergency cognitive radio system, tests were carried out to verify the percentage of PU detection in order to avoid transmitting on a frequency that was in use by a PU. At the same time, the level of signal to noise present in each modulation and the execution times of the emergency system could be determined.