Phase-locked tracking loop-based through-wall detection wall body suppression method

Abstract

The invention discloses a phase-locked tracking loop-based through-wall detection wall body suppression method. The method includes the following steps that: 1) original echo signals received by a receiving antenna are multiplied by the sine and cosine of local carriers respectively which are generated by a PLL (phase locked loop) module, after the carriers are removed, the signals are divided into two paths of signals; 2) the two paths of signals are transmitted to a first DLL module together, and after the delay phase tau of an M sequence is calculated, the M sequence is outputted, and is multiplied by the cosine of the carriers outputted by the PLL module, so that direct wave signals can be obtained; 3) subtraction is performed on the received original signals and the direct wave signals, so that direct wave-free signals can be obtained; 4) processing modes from the step 1) and the step 3) are repeated through a plurality of DLL modules sequentially, and target echo information can be obtained finally, and the method terminates. The method of the invention has the advantages of proper signal to noise ratio and accurate target detection when being applied to through-the-wall radars.

Description

technical field [0001] The invention belongs to the technical field of radar through-wall detection, and relates to a wall suppression method for through-wall detection based on a phase-locked tracking loop. Background technique [0002] The through-wall radar transmits electromagnetic waves of specific frequencies to penetrate and detect non-transparent media such as walls, wood boards, and trees. Electromagnetic waves of 0.5GHz to 3GHz have a good penetrating ability to walls and will not harm the human body. Through-the-wall radar can pass through concrete walls, slate walls, and wooden walls, etc., and has a wide range of applications in post-disaster rescue, hostage rescue, and urban combat. In the imaging of through-wall radar, due to the existence of the wall, when the electromagnetic wave penetrates the wall, the electromagnetic wave will be reflected, refracted and changed in speed, resulting in time delay, attenuation and distortion of the signal; the image of the ...

AI Technical Summary

Problems solved by technology

[0004] The object of the present invention is to provide a wall-through-wall detection wall suppression method based on a phase-locked tracking loop, which solves the problem of wall parameter estimation errors in the prior art that lead to detection target position errors, and the target and wall confusion in the echo signal. Overlapping makes it impossible to separate target information

Images