V.S. Efimenko, V.N. Kharisov
Tracking systems for carrier of radio signal are a weakest link in modern radio engineering devices and define their anti-jam (A-J) capability as a whole. Therefore authors consider as the main task of article demonstration of a prize which provides application of algorithms of an optimal filtering (OF) to a problem of an estimation of a phase and frequency of radio signals. Thus for synthesis the method optimal trajectory filtering (OTF) is used.
OTF was offered in 2002 year and its main difference from classical Stratonovich’s OF consists in the following. The criterion in OF is connected with a point estimation during the separate moment of time (considered sometimes within the limits of OF the interval estimation is reduced to set of point estimations). In OTF the maximum likelihood estimation of all trajectory is searched. Generally these estimations do not coincide.
The choice of second order model of dynamics has allowed to compare h algorithms OTF characteristics both with classical PLL, and with potential characteristics of Frequency Locked Loop. Thus we were guided by reception conditions, characteristic for radio navigation systems for which because of extremely low power of a signal questions A-J capability are especially sharp. It is shown by modelling that algorithm OTF combines accuracy coherent and a A-J capability of noncoherent algorithms.
Characterizing the complexity of the realisation of the proposed algorithms OTF in the task of monitoring the carrier, we can say that the current state of development of the electronics makes the problem of their realisation in the receivers quite relevant and practically feasible.