A method of ultrasonic target detection based on ofdm signal
A target detection and signal technology, which is applied in the field of ultrasonic target detection based on OFDM signals, can solve problems such as low signal-to-noise ratio and recovery of echo signals, and achieve the effects of eliminating noise, saving design costs, and reducing system design complexity
Inactive Publication Date: 2019-06-04
NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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[0006] Aiming at the deficiencies of the above-mentioned prior art, the object of the present invention is to provide an ultrasonic target detection method based on OFDM signals, which solves the problem of low signal-to-noise ratio and weak echo in the traditional single-pulse ultrasonic detection technology in the prior art. The problem that the signal is difficult to recover from the noise
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[0036] In order to facilitate the understanding of those skilled in the art, the present invention will be further described below in conjunction with the embodiments and accompanying drawings, and the contents mentioned in the embodiments are not intended to limit the present invention.
[0037] The invention makes an analogy between the principle of ultrasonic detection technology and the multipath effect in wireless communication, and designs an algorithm based on OFDM multi-carrier frequency domain estimation to realize ultrasonic target detection. The method is based on the following system, which includes: a link structure at the transmitting end for transmitting OFDM signal waveforms, and a link structure at the receiving end for processing echo signals.
[0038] refer to Figure 1a , Figure 1b As shown, the system sampling rate fs=100MHz, the transmitted signal bandwidth B=10MHz, the Zadoff-Chu sequence length N=256, and the cyclic prefix length is 256, so the modulat...
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The invention discloses an ultrasonic target detection method based on an OFDM (Orthogonal Frequency Division Multiplexing) signal. A Zadoff_Chu sequence is modulated into the OFDM signal to estimate a target distance and realize sidelobe-free pulse compression. According to the method, a target signal can be favorably detected under a low signal-to-noise ratio, the problem of pulse sidelobe is solved since an OFDM technology in wireless communication is applied to ultrasonic target detection, the problem of noise sidelobe is solved, system design complexity is lowered, system performance is improved, and the ultrasonic target detection method has a wide application prospect in the technical field of ultrasonic detection.
Description
technical field [0001] The invention belongs to the technical field of industrial automation and testing and measurement, and specifically refers to an OFDM signal-based ultrasonic target detection method. Background technique [0002] Ultrasonic flaw detection is a non-destructive testing method that uses the difference in acoustic properties of materials and their defects to the energy changes in the reflection of ultrasonic wave propagation and penetration time to test internal defects in materials. Generally, in a homogeneous material, the existence of defects will cause the discontinuity of the material, and this discontinuity will often cause the inconsistency of the acoustic impedance. It can be known from the reflection theorem that ultrasonic waves will occur at the interface of two media with different acoustic impedance. Reflection, the amount of reflected energy is related to the difference in acoustic impedance of the medium on both sides of the interface and th...
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IPC IPC(8): G01N29/36H04L27/26
CPCG01N29/36G01N2291/0289H04L27/2601
Inventor 戴晶晶卢智聪徐大专
Owner NANJING UNIV OF AERONAUTICS & ASTRONAUTICS