Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: linear frequency modulation

Sortuj według:

Ogranicz wyniki do:

Chirp signals with phase coding

Marciniak B., Marciniak T.

Image Processing & Communications

2009

Vol. 14, no 1

51-56

The main problem associated with detecting and locating of objects by means of radiolocation and hydrolocation systems is the appropriate selection of transmitting signals. These signals need to be difficult to detect by the watched object and need to be resistant to disturbances. The most often used ones are signals with linear frequency modulation (chirp signals) and signals with phase coding. New possibilities of the realization of complex signals appeared along with development of the digital technique. The usage of signal composite from short signals with linear frequency modulation with use of phase coding was analysed in this paper. Short noise-like sequences (Barker's codes) were used for coding the initial phase of chirp signals. This article presents results of research obtained for a signal of this type, at its identification by means of matching filtration. These results were compared with results obtained for single signal with linear frequency modulation with the same duration and bandwidth.

The simple analysis method of nonlinear frequency distortions in FMCW radar

Kulpa K. S., Wojtkiewicz A., Nałęcz M., Misiurewicz J.

Journal of Telecommunications and Information Technology

2001

nr 4

26-29

The paper presents a simple method for estimating nonlinear frequency distortions of linear frequency modulated (LFM) signals used in FMCW radars. This method, derived from the polynomial model of the nonlinear FM signal phase, is based on finding the maximum of two-dimensional chirp-like transform of the IF video signal. The IF signal is obtained by mixing transmitted FM signal with its delayed copy. Using suggested transform we show that the presented method is able to detect and classify signal distortions.