The Charateristic Of Time-Frequency Atom Dictionary Research On Radar Emitter Signal

The time-frequency atom decomposition of radar emitter signals is decomposing the signal into linear expansion on the time-frequency atoms, to get the flexible express of signals. Because of using the best time-frequency atoms to decompose signals, time-frequency atom decomposition can choose the time-frequency atoms from the over-complete dictionary of atoms to match the signal's overall and local structures and obtain the useful informations of the emitter signals. However the time-frequency atom dictionaries have many kinds and different features. It is difficulty to select time-frequency atom dictionaries according to the features of emitter signals, and is worth to further study and discuss.It is an important significance to study the performance of time-frequency atom dictionaries and select best time-frequency atom dictionary for the emitter signals which have the different characteristics to obtain the signal best representation and provide reference for extracting the time-frequency atom features from emitter signals. Until now, only few works have been done on selecting the time-frequency atom dictionaries for the radar emitter signal at home and aboard. Therefore, building the time-frequency atom dictionaries for the radar emitter signals which have different characteristics and selceting the time-frequency atom dictionaries which have the best structure for radar emitter signals are present in this paper. The main work and research fruits are as follows:1. Five time-frequency atom dictionaries having different structures are studied and their performances are compared. The time-frequency atom dictionaries are selected according with the features of emitter signals for the emitter signals having the different characteristics. Five different types' emitter signals are decomposed using five time-frequency atom dictionaries. The experiment results show that the characteristcs of the signal will be shown accurately only to select the time-frequency atom dictionaries having good structure and performance.2. The single time-frequency atom dictionary can not show the characteristics of the multi-component emitter signal accurately. Twenty-six kinds of mixed atom dictionaries are formed by the five different atom dictionaries and their performances are researched. They can provide the methods to select the time-frequency atom dictionary for multi-component emitter signal. Experiments are carried out on 26 kinds of mixed atom dictionaries to decompose the different kinds of multi-component emitter signals. The experiment results show that if independent mixed atom dictionary having similar structure is selected to decompose the multi-component emitter signal, the characteristics of the multi-component signals will be shown accurately. This work is supported partially by the National Natural Science Foundation of China (60702026). the Scientific and Technological Funds for Young Scientists of Sichuan (09ZQ026-040) and the open Research Fund of Key Laboratory of Signal and Information Processing. Xihua University (SZJJ2009-003).