N. M. Ashimov, I.V. Grachev, A.V. Kravtsov
Work concerns area of information technologies and digital processing of signals. It is known, that the greatest reliability of reception of signals is reached at application of the coordinated filters which can be realized only digital methods. Distinguish before detecting and. After detecting the coordinated filtration. In the first case the filter is strip and will be coordinated with a radio signal of final duration, in the second case is used the bottom frequencies which will be coordinated with video signal (with bending around a radio signal). It is necessary to prefer the strip coordinated filter at which application higher noise stability is reached. However realisation of the digital strip filter is connected with labour-consuming operation of digital multiplication at calculation of integral of convolution that complicates the scheme of processing of a signal and increases hardware expenses.
In the given work it is offered the kvazioptimal strip digital filter which pulse characteristic has the form rectangular impulses. At calculation of integral of convolution in this case operation of digital multiplication is replaced with operation of simple addition of digital readout of a signal. It allows to simplify considerably the scheme and to reduce hardware expenses.
There is an optimum size of the relation of total duration of the pulse characteristic of the filter to duration of an accepted radio signal at which the signal/noise on a filter exit reaches the relation of the maximum value. This relation signal/noise on pressure only on 4 % is less in comparison with the coordinated filter.
Insignificant loss in the relation signal/noise at more simple realisation allows to recommend the kvazioptimal digital strip filter for practical use.