Two-Time Procedure for Calculation of Carrier Frequency of Phasomodulated in Communication Systems

The use in radio communication systems of phase modulation of a signal intended for the transmission of useful information in a continuous mode creates the problem of frequency uncertainty of the received signal by frequency.In practice, it is not possible to implement frequency estimation in the conditions of chat uncertainty of the signal in the channel with low energy of the signal received in the continuous mode. Therefore, the estimation of the carrier frequency offset of the signal received relative to the nominal value is carried out before other synchronization procedures are included, namely: phase synchronization and clock synchronization. The paper generalizes the procedure and forms a two-step procedure for calculating the carrier frequency of the phase-modulated signal of a radio communication system for data transmission in a continuous mode, taking into account the condition of uncertainty of all signal parameters. Achieving the minimum observation interval in the given order of calculation of the carrier frequency is ensured by the use of the fast Fourier transform function. In order to analyze the effectiveness of this procedure, the process of estimating the carrier frequency of the phase-modulated signal of the radio communication system during data transmission in continuous mode and functional dependences of the maximum frequency in the signal spectrum and the minimum variance of carrier frequency estimation. This procedure allows a two-stage assessment of the carrier frequency according to the rule of maximum likelihood, taking into account the condition of uncertainty of all parameters of the signal received by the satellite communication system in a continuous mode with a minimum observation interval. Achieving the minimum observation interval in the given order of carrier frequency estimation is ensured by using the fast Fourier transform function and two estimation steps. The analysis of the efficiency of the estimation of the specified order was carried out on the basis of comparison of a ratio of the received minimum variance of an estimation of a carrier frequency and theoretically possible border of the minimum variance

Methods for assessing the impact of bandwidth of control channels on the quality of telecommunications networks in the transmission of data packets of different types

Abstract: It is known that since the early 2000s there has been a rapid increase in data traffic and a significant increase in the need for information flows in the process of providing new types of telecommunications services. This has led to the fact that the existing telecommunications networks have failed or approached the limit of their ability to serve subscribers with specified quality of service. The problem of improving the network architecture of such networks and improving the quality of their operation based on the use of modern methods and principles has arisen and needs constant solution. In this paper the requirements to the bandwidth of the channels of the telecommunication network management system in modern conditions are analyzed and their formalized description is given. In order to assess the bandwidth of the channel of the control network of the telecommunications network on the indicators of the quality of its work in the transmission of various types of data in the work developed and submitted an appropriate methodology. The method is based on mathematical dependences that describe the process of functioning of the telecommunication network management system based on the application of the laws and rules of queuing theory