CAJ | 학술논문

由于随机共振具有在特定条件下增强微弱信号信噪比的特性，近年来成为一种全新的微弱信号检测手段。为了克服随机共振绝热近似理论小参数条件的限制，提出一种基于欠采样随机共振的微弱信号检测方法。通过欠采样尺度变换与还原技术，实现了大参数信号的随机共振处理，突破了二次采样变尺度随机共振算法要求采样频率必须大于信号频率的50倍的限制。构建了基于欠采样随机共振的微弱信号检测模型，从理论上证明了方法的可行性。最后利用该方法对信噪比为-27 dB条件下的微弱单频信号检测进行了仿真，结果进一步验证了所提微弱信号检测方案的正确性。所提方法大大降低了信号的采样速率，为将随机共振应用于科斯塔斯( Costas)环的改进奠定了基础。
유우수궤공진구유재특정조건하증강미약신호신조비적특성，근년래성위일충전신적미약신호검측수단。위료극복수궤공진절열근사이론소삼수조건적한제，제출일충기우흠채양수궤공진적미약신호검측방법。통과흠채양척도변환여환원기술，실현료대삼수신호적수궤공진처리，돌파료이차채양변척도수궤공진산법요구채양빈솔필수대우신호빈솔적50배적한제。구건료기우흠채양수궤공진적미약신호검측모형，종이론상증명료방법적가행성。최후이용해방법대신조비위-27 dB조건하적미약단빈신호검측진행료방진，결과진일보험증료소제미약신호검측방안적정학성。소제방법대대강저료신호적채양속솔，위장수궤공진응용우과사탑사( Costas)배적개진전정료기출。
Stochastic resonance is widely applied to detect weak signal in a strong noise background be-cause it can enhance the signal-to-noise ratio(SNR). A weak single frequency signal detection method based on under-sampling stochastic resonance is proposed to solve the problem that traditional stochastic resonance can be only applied to deal with small parameter signals. Stochastic resonance is successfully ex-panded into the applications of the large parameter signals on the basis of scale-transformation and retrieve technology in the under-sampling stochastic resonance. Moreover,the algorithm overcomes the limit that signal frequency must be more than 50 times of the sampling frequency in the second sample algorithm. The model of weak signal detection based on under-sampling stochastic resonance is put forward. Finally, detecting the weak single frequency signal under SNR=-27 dB background by the method proposed in this paper is simulated. The result proves the validity of the method. The sampling frequency in the method is much less than that in the traditional methods and this is helpful to apply stochastic resonance in improving the performance of the Costas loop.