Practical aspects of noise immune data transmission channel design in telecommunication networks

Abstract

Practical aspects of noise immune data transmission channel design in telecommunication networks are considered. Main accent is made on securing noise immunity and concealment of information transmission, as well as on countering its interception by the rogue elements. It is noted that satisfaction of the mentioned requirements is possible by using spectrum spreading of useful signal bits and deploying data scrambling. Design of telecommunication channel with spectrum spreading and scrambling on the base of pseudo noise coding sequences derived from primitive polynomials of the eighth and fifteenth order that possess good auto and inter correlation properties are proposed. While studying practical aspects of the telecommunication channel design, its structure is put forward that consists of frames counting 256 bits, each of which is spread by using the synthesized pseudo noise sequence. In this case, the second synthesized pseudo noise coding sequence with the length of 32768 chips is used to mark the frame duration and perform additional information scrambling. Computer simulation is employed to study performance of the designed algorithm. Simulation results proved that processing of the additive mixture of the useful signal and interferences, which surpass useful signal two times in their power, by the matched despreading filters permits to confidently determine the frame structure of the information being transmitted by finding frame beginning pulses and determining values of the useful information bits. Analysis of the results obtained during the research permits to assume that designed telecommunication channel can be successfully used while developing noise immune concealed telecommunication networks. It is proposed to carry out further research to study boundary possibilities of the designed telecommunication channel in terms of useful signal to interference ratio.