Method for constructing phase jitter DDMA waveform

Abstract

The invention discloses a method for constructing a phase jitter DDMA waveform, which comprises the following steps of calculating Doppler frequency of the phase jitter DDMA waveform of a transmittingarray element according to the number of the transmitting array elements and pulse repetition frequency, according to the signal received by any receiving array element and the calculated Doppler frequency, calculating a Doppler domain signal component of a phase jitter DDMA waveform of the receiving array element by using a target aliasing formula, wherein the Doppler domain signal component atleast comprises frequencies and phases of clutter signals on a transmitting array element on each orthogonal slow time channel, constructing an intensity accumulation expression of clutter signals according to the calculated frequency and phase, and searching the intensity accumulation expression in an angle interval of [0, 2pi] to obtain an optimal initial phase set corresponding to the clutter with the minimum intensity. The DDMA signal can be applied to the airborne slow-time MIMO radar, so that the blind speed problem of target detection caused by Doppler ambiguity easily caused by the DDMA signal is reduced.

Description

technical field [0001] The invention belongs to the technical field of radar signal processing, and in particular relates to a construction method of a phase-jittered DDMA waveform. Background technique [0002] MIMO (Multiple Input Multiple Output) radar is a new system that has attracted much attention. The concept of MIMO radar was proposed by Fishler of MIT Lincoln Laboratory in 2004. It successfully borrowed from modern The MIMO technology in the communication field is a further development of the traditional phased array radar. Theoretical studies show that compared with traditional phased array radars, airborne MIMO radars can improve performance in many aspects such as clutter suppression, low-speed target detection, and detection of weak targets in strong clutter backgrounds. [0003] Slow-time MIMO is a special mechanism that achieves waveform orthogonality after Doppler processing at the receiving end through pulse-to-pulse phase encoding. Under this mechanism, t...

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Problems solved by technology

[0004] However, under the premise that the pulse repetition frequency that determines the unambiguous distance remains unchanged, the Doppler unambiguous interval of the DDMA signal is smaller; if the target speed is too large, the target echo of one transmitting array element may be mistaken for another The low-speed target echo of a transmitting array element may also have the same Doppler frequency as the main lobe clutter of the other transmitting array element, resulting in a blind speed problem that the target cannot be detected

Therefore, how to make the DDMA signal suitable for the airborne slow-time MIMO radar, thereby reducing the blind speed problem of target detection caused by the Doppler ambiguity easily caused by the DDMA signal, there is no better solution in the prior art

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