Pulse segmentation coding method for eliminating radar target blind speed

Abstract

The invention belongs to the technical field of radars, and discloses a pulse segment coding method for eliminating radar target blind speed, which comprises the following steps: determining a slow time linear phase phi m (k) and a corresponding transmitting signal sm (t); segmenting the pulse, and adding a random phase or a fixed phase to each segment of pulse to obtain a slow-time linear phase phi'm (k) after the phase is added and a corresponding transmitting signal s'm (t); enabling s'm (t) to reach the nth receiving array element after target scattering to obtain an echo signal smn (t); superposing the echo signals to obtain an output signal Sn (t) of the nth receiving array element; performing down-conversion and matched filtering on the Sn (t) to obtain echo signals Xn, i (t) aftermatched filtering and a fuzzy function of a corresponding DDMA radar; performing FFT on the Xn, i (t) to obtain a frequency domain signal znk ', i, and performing clutter suppression by adopting a space-time adaptive processing method; according to the method, the Doppler ambiguity problem of the DDMA MIMO radar can be solved, the target blind speed is eliminated, the mode of accurately controlling the phase is expanded, the performance deviation caused by random phase contingency is weakened, and the minimum detectable speed is better.

Description

technical field [0001] The invention relates to the field of radar technology, in particular to a pulse segmentation encoding method for eliminating the blind speed of a radar target, which can solve the problem of Doppler ambiguity in DDMA MIMO radar echoes, and is used for eliminating the blind speed of a radar target. Background technique [0002] Traditional Multiple Input Multiple Output (MIMO) radars need to equip each transmitting element with an independent waveform generator, which leads to high cost. In addition, the orthogonal waveform will also destroy the echo correlation of the clutter, so that the clutter suppression cannot rely on the launch degree of freedom. Using Doppler Frequency Division Multiple Access (DopplerDivision Multiple Access, DDMA) waveform MIMO radar is expected to overcome the above two problems, and may be used in airborne radar. It is built on the basis of conventional single input multiple output (Single Input Multiple Output, SIMO) rada...

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Problems solved by technology

[0006] However, the above two methods will lead to higher side lobes of clutter suppression processing, and a larger minimum detectable speed of the target, which is not good for slow and weak target detection.

[0007] Van Rossum and Anitor proposed a slow-time code division multiple access (ST-CDMA) waveform in 2018, in which the different transmit waveforms in each pulse are orthogonal, similar to, but different from, the DDMA waveform The most important thing is that the phase multiplied by the waveform is not a slow-time linear phase, but a random phase. This method can effectively detect weak and small targets, but this method must be combined with sparse signal processing, which requires a large amount of calculation and is complicated.

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