P.S. Gribov – Post-graduate Student, Department of Radiotechnical Systems, National Research University «MPEI», Researcher, «NAVIS» Design Department,
A.Yu. Shatilov – PhD(Eng), Associate Professor, Department of Radiotechnical Systems, National Research University «MPEI», Head of Department, «NAVIS» Design Department
Use of the adaptive antenna array allows to increase considerably noise stability of the equipment of consumers of satellite radio navigational systems due to formation of failures of a directional diagram in the direction of sources of interferences. The adaptability of the applied algorithms is caused by unpredictable change of the directions of arrival of interfering signals, an angular position of a receiving antenna and also not predicted change of complex frequency characteristics of transmission channels from a interference source to exits of analog to digital converter, the bound to such factors as a multipath, polarization and interference of elements of an antenna array. In article application of preliminary spatial processing of signals in a problem of an adaptive space-time rejection of interferences at reception of signals of satellite radio navigational systems on an antenna array is considered. It is known that a preprocessing reduces time of convergence of algorithms of the space-time compensator of interferences of gradient type. In work it is shown that in the conditions of not identity of the frequency characteristics of channels of the adaptive antenna array a pretreatment, in addition, allows to improve effectiveness of suppression of interferences. Authors offered the way of a preprocessing eliminating a defect of existing. In article it is shown that in conditions without interferences leads use of a preprocessing with own decomposition of a complete correlation matrix (the known method) to significant distortions of an adaptive directional diagram that, in turn, worsens conditions of reception of navigation signals. The preprocessing method offered by authors with the address of a complete correlation matrix doesn't lead to distortions of a form of an adaptive directional diagram. Besides, results of comparative analysis of effectiveness of a rejection of interferences by means of various algorithms of processing of signals of adaptive antenna array in the conditions of not identity of the frequency characteristics of receiving channels of adaptive antenna array and action of broadband hindrances are presented. According to authors existence of not identity of receiving channels of adaptive antenna array is the universal and most significant factor limiting effectiveness of suppression of radio interferences in the real equipment. For comparative analysis algorithms of adaptation of weight coefficients of adaptive antenna array which have minimum computing complexity are chosen and therefore were widely adopted also implementation. Here, according to authors, carry an optimum spatial filter, an algorithm Widrow (or a method of least squares), an algorithm Widrow together with various methods of a pretreatment. Results of comparative analysis are got by a simulation modeling a work of adaptive antenna array. The purpose of article is the description of a way of preliminary spatial processing of signals (to the compensator) in adaptive antenna array, and receiving comparative assessment of effectiveness of a rejection of interferences with others, the most widespread, algorithms of a rejection of interferences with not identity of receiving channels of adaptive antenna array.
- Monzingo R.A. Adaptivnye antennye reshetki. M.: Radio i svyaz. 1986. (in Russian)
- Uidrou B., Strinz S. Adaptivnaya obrabotka signalov. M.: Radio i svyaz. 1989. (in Russian)
- Gribov P.S., Shatilov A.Yu. Model vykhodnykh signalov antennoi reshetki dlya sinteza algoritmov prostranstvennogo podavleniya pomekh. Radiotekhnika. 2018. № 9. S. 163−168. DOI 10.18127/j00338486-201809-27.(in Russian)
- Kanatnikov A.N., Krishchenko A.P. Lineinaya algebra. M.: MGTU im. N.E. Baumana. 2006. (in Russian)