Scatter Signals Extraction Algorithm And Array Signals Processing Architecture In Passive Location System

In Passive Location System, where it implements inspection and location by no-cooperation of civil broadcast stations, the scatter signals always submerge among the strong direct signals as well as multi-path interference. In order to extract weak scatter signals from the mixed receive signals, it would be a must to suppress the intensity of strong direct signals and background noises. Only in this way, can realized Multi Target Inspection and Identification, combining with subsequent technology of Time-domain Elimination, TDOA Estimation and Blind Signals Equalization.The solution of weak scatter signals extraction proposed in this thesis is mainly about how to form the Nulls and widen their width, basing on Antenna Array Process and some appropriate Auto-Adaptive Algorithms, for the purpose of interferences suppression as well as scatter signals extraction.Traditional spatial signals processing basically involves beam forming technology and null forming technology, both of which are based on array sampling signals processing. The beam forming technology aims to form the main-lobe in the needed direction, while null forming technology's major task is to make null in the direction of interferential signals. In other words, the former is used to enhance the intensity of interested output signals, and the latter is used to reduce the intensity of interferential signal. In fact, both of them are targeting increasing the SIR. Additionally, Spatial Spectrum Estimation technology is also concern the DOA estimation problem. It would bring great advantages if all of them are combined efficiently.This thesis is organized as follows. First, we introduce the principle of traditional beam forming and the structure of digital, analog, digital-analog beam former. Secondly, the recent blind DBF algorithms, the advantages as well as disadvantages are briefly summarized. Then with regard to different array patterns, their individual null effects are simulated via numerical value optimization. A lot of effort was taken in how to deepen and widen the zero point through the transform of array steer vector and self-covariance matrix, basing on the traditional weight calculation formula. Finally, some primary research about hardware platform implement basing Soft Defined Radio is concisely discussed.This paper was supported by national space foundation.(NO:20060307)...