Требования к кодирующей матрице фазокодоманипулированного зондирующего сигнала с нулевой зоной автокорреляции.

Abstract

Optimal discrete signals does not allow solving the problem of radar range resolution for echo signals overlapping in time with significantly different amplitudes. Also, these signals limit the possibility of improving the quality of the radar image in radar of different applications due correlation noise. Therefore, to solve the above problem, it is of interest to use a probing signal with a zero autocorrelation zone. To form an autocorrelation function with a zero sidelobes region, the probing signal must be a pulse train of two or more phase-code-manipulated pulses. It is analytically substantiated in the paper that in order to form a zero autocorrelation zone, a pulse train of pulses must be coded by an ensemble of complementary or orthogonal sequences. In this case, the probing signal will have a large number of pulses in a pulse train, which makes it difficult to use it in a radar with a common transmitting and receiving antenna. It is shown that when coding by an ensemble of complementary sequences, the complex envelopes of all discrete pulses in a pulse train must be equal. In this case, the compressed signal will have a sufficiently high sidelobe ratios in a zero autocorrelation zone with Doppler mismatch. It has also been analytically proved that in order to form a zero autocorrelation zone, a pulse train of pulses can be coded by rows of a block matrix, consisting of a set of mutually orthogonal matrices. Then the complex envelopes of discrete pulses in a pulse train can be different, which makes it possible to suppress the level of sidelobes in a zero autocorrelation zone with Doppler mismatch. The paper also contains the requirements for the coding matrix of a polyphase (p-phase, where р ≥ 2 – prime number) probing signal with a zero autocorrelation zone, consisting of a minimum number of pulses in a pulse train equal to p, called a coherent complemented signal.