One of the important directions of improvement of the user navigation equipment is increase of its noise stability. Now devices of spatial-time signal processing became the main instrument for ensuring of a high noise stability. Therefore a great interest represent both questions of creation of such devices, and their technical characteristics, achievable in actual practice applications. In article these questions are considered in relation to the small-sized adaptive antenna array (AAR).
The presented features of algorithmic providing consist in the following. Considered antenna array represents the four-element adaptive antenna array functioning by the principle of the adaptive canceler of interference, minimizing output noise dispersion. For determination of weight coefficients the algorithm of gradient descent is used. Besides, correcting filters on the basis of lines of delays with branches which provide both alignment of reception paths, and suppression of the rereflected hindrances are used.
In relation to features of technical realization, when developing , the special attention is paid to a problem of not identity of reception paths. For increase of efficiency of correction reception paths of analog filters of a low order are used. The main filtration and correction is carried out in digital filters. In analog part of reception paths the superheterodyne scheme with one transformation of frequency is realized. The second transformation of frequency happens when sampling in ADC.
Tests of AAR are presented by results of laboratory and natural researches. Within laboratory researches the potential coefficient of suppression of 64 dB is received. It is thus noted that one of the most essential limiting factors who limits suppression coefficient at natural tests is the multipath jammer propagation.
When carrying out natural experiments the following indicators of a noise stability were estimated: gain of a noise stability and threshold value of the relation J/S jammer/signal. The first indicator was defined as the relation of capacities of hindrances of reciever necessary for suppression with AAR and reciever without AAR. For an assessment of the second indicator hindrance capacity was measured only, and the capacity of a signal undertook equal specified in lCD.
The carried-out natural land and flight tests showed that the gain of a noise stability of studied AAR at influence of a broadband hindrance made 56 dB, and J/S=92 ... 108 dB.
Jaskin Ju.S., Xarisov V.N., Efimenko V.S., Bojko S.N., By'strakov S.G.,
Pastuxov A. V., Savel'ev S.A. Xarakteristiki podavleniya pomex v pervom
obrazcze pomexoustojchivoj apparatury' potrebitelej SRNS GLONASS/GPS s
adaptivnoj antennoj reshyotkoj // Radiotexnika (Zhurnal v zhurnale). 2010. № 7. S. 127–136.