Study Of The UWB Pulse Compression Through-Wall Radar And Side-Lobe Suppression

With the development of radar’s technology, radar’s application range transforms military field into other fields. Especially in the civilian field which just likes resource survey, search-and-rescue and so on, radar is needed more and more, so the advancement of radar’s technology faces serious challenge. Ultra Wide Band radar is put forward under the circumstances. Because of its advantages--high sensitivity, anti-intercept, multifunction and self-adaption, it attracts many scholars in interest and attention.This article mainly targets the question that traditional through-wall radar has low resolution ratio and high-frequency radar is lack of penetrating power, and put forward the UWB pulse compression through-wall radar to solve this question which the radar cannot have both width-time and wide-band. The major work of this paper is summarized as follow:1. Based on the ambiguity function of radar’s system, the problem of the radar’s range resolution and speed resolution is analyzed, and the basic theory of UWB pulse compression radar is expounded.2. Each state of signal’s emission and reception (such as transmitting signal, echo signal of the wall, echo signal of the target and filter’s output result and so on). UWB pulse compression through-wall radar’s system combined with Finite Difference Time Domain is described under1-D environment.3. It is easy to cause the phenomenon of distance side-lobe by pulse compression algorithm based on traditional matched filter, and what is more, it causes strong target signal to cover weak target signal and to reduce resolution of radar system. Aim at these above problems, the output result is filtered by common window function firstly. The suppress result by simulation of computer is used to analyze the performance of different kinds of window function. Then, Minimum Mean Square Error Filter is given and used to replace the Matched Filter, and the simulation result of computer is analyzed again. On the basis of MMSE filter, Kalman-Minimum Mean Square Error (K-MMSE) filter is put forward. The theory of Kalman filter is described and its mathematical formula is deduced. The filter is solely simulated by computer and the result is analyzed. And then, the theory of K-MMSE filter is described in detail and simulated by MATLAB language on computer. The performance of K-MMSE filter is analyzed by comparing with Matched Filter, Kalman Filter system and MMSE Filter system. The simulation result shows, K-MMSE filter is better than other filters to some extent, and have a better result of side-lobe suppression.