Comparação de interferências intencionais sobre sistemas de comunicação digital convencionais e com espalhamento espectral

Abstract

The spread of digital communications raises concerns about their possible malicious use. In order to inhibit the misuse of these technologies, countermeasures with intentional interference can be used. This Final Course Project seeks to compare the efficiency of the following jamming techniques: (i) single tone, (ii) multiple tones, (iii) narrow-band noise (NBN), (iv) tone pulse, (v) NBN pulse and (vi) swept jamming. The jamming techniques will be evaluated in a conventional BPSK communication system and in a direct sequence spread spectrum (DSSS) system, both operating on AWGN channel. The objective is to identify the most effective jamming technique for each scenario evaluated. To enable the analyses, the BPSK and DSSS BPSK transmission and reception systems, and the jammers were simulated in the MATLAB® software. Based on the BER curves obtained through the simulation, comparisons were made of the performance of the two systems under the action of each jamming technique evaluated in the work. It is concluded that the spread spectrum brings significant performance gains in interference scenarios. Furthermore, it was found that single-tone blocking is the most effective against conventional digital communication systems in the scenario presented and with the simulation parameters used. Regarding the DSSS system, the best jamming technique will depend on the signal-to-noise-interference ratio (SINR) under which the interfered receiver is evaluated.