弱目标检测

2012 7th International ICST Conference on Communications and Networking in China (CHINACOM)
A High-resolution Weak Signal Detection
Method Based on Stochastic Resonance
Key works: weak signals, stochastic resonance, superhet technology
Ⅰ. INTRODUCTION
Compared with noise, the amplitude of a signal is weak; the signal is completely submerged in the noise. On signal detection, the detection of the particular frequency is the most important.
In the past, the weak signal detection in general focused on the methods of reducing noise to improve the signal to noise ratio (SNR), but often damaging the actual signal in the process of suppressing noise. Stochastic resonance (SR) in this bistable system can take advantage of the noise energy to improve the signal detection capability. But stochastic resonance can only be used for the low frequency signals, thus, its utility has limited application[1-2]. In this paper, the frequency range of
The concept of stochastic resonance was put forward by the Italian physicist Roberto Benzi, American physicist Alfonso Sutera and Italian physicist Angelo Vulpoiani in the study of ancient meteorological glaciers in 1981 [1].
2Harbin Institute of Technology 3University of Science and Technology of China
Abstract-A detection method based on the strong low-frequency weak-signal detection ability of stochastic resonance is proposed, aimed at the detection of the unknown weak signal. By mixing the unknown signal with a continuous linear changing local oscillator signal, a difference frequency signal will be generated, which will be sent to the stochastic resonance system. Thus, an obviously changed output can be obtained. Because the stochastic resonance system is extremely sensitive to low frequency, the system will have a maximum output when the local oscillator and frequency of the unknown signal are closest. The frequency of the unknown signal will be measured precisely from the local oscillator frequency and the difference frequency. It can be inferred from the theoretical analysis and numerical simulation that this method has a large detection range, high resolution, and good prospect.
detection of stochastic resonance system is discussed and recommendations are made for a high-frequency weak signal detection method.
Ⅱ. THE PRINCIPLE OF STOCHASTIC RESONANCE
and Superhet Technology
12Shuo Shi, 12Wanyi Yin, 12Mingchuan Yang, 3Mingjie He 1National Key Laboratory of Communication System and Information Control Technology
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Stochastic resonance describes the phenomenon of back and forth transition between noise and the periodic signal, in non-linear bistable system under overdamped Brownian particle motion[4]. The potential curve of the non-linear bistable system and the transitions curve of particlse between the two potential wells is shown in Fig.1. x(t) is the position of the output particles at any time, and this introduces the equation describing the particle motion-Langevin equation[5-6].