面向小型载荷的宽带通信信号随机共振检测方法
A Stochastic Resonance Detection Method for Broadband Communication Signals in Small Loads
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摘要: 随着人工智能等领域的飞速发展,无人机在各个领域,尤其是现代战争中发挥着越来越重要的作用。无人机凭借其强大的灵活性和高隐蔽性优势,对现代作战具有颠覆性影响。在无人机执行战场侦察、监视、通信、电子干扰、雷达诱骗、激光制导等任务的过程中,及时探测敌方辐射信号尤为重要。随机共振方法利用特定非线性系统可以使输入其中的信号与噪声在一定条件下产生协同作用的特点,将噪声的能量转移到信号中来放大信号,是常用的微弱信号检测方法之一。窄带信号的随机共振检测技术已趋于成熟。而对小型载荷无人机监视、通信等场景下的微弱宽带通信信号,现有随机共振检测方法直接采用窄带信号的时域能量检测方法,并未基于宽带信号特点设计专门的检测方法,低信噪比条件下检测性能受限。为了满足对微弱宽带通信信号的检测要求,本文以常用的宽带通信信号为研究对象,对于单通道接收场景,提出基于宽带信号局部频谱的随机共振信号检测方法,该方法与传统的随机共振信号检测方法相比性能提升约6 dB。其次,对于更低信噪比的情况,提出一种随机共振与互相关检测相结合的双通道协同检测方法,并提出基于随机共振后两路互相关系数最大化的系统参数优化准则。典型场景下的仿真分析表明,对于单通道接收的低信噪比微弱宽带通信信号,局部频谱法可以有效提升检测性能;对于更低信噪比宽带通信信号,采用随机共振处理后的双通道互相关检测可以进一步提升检测性能。Abstract: With the rapid development of artificial intelligence and other fields, unmanned aerial vehicles play an increasingly important role in various fields, especially modern warfare. With their strong flexibility and high concealment advantages, UAVs have a subversive impact on modern operations. For the UAV to carry out battlefield reconnaissance, surveillance, communication, electronic jamming, radar decoy, laser guidance, and other tasks, timely detection of enemy radiation signals is particularly important. The stochastic resonance method is one of the commonly used weak signal detection methods, which can make the input signal and noise produce a synergistic effect under certain conditions by transferring the energy of noise to the signal. The technique of stochastic resonance detection for narrow-band signals has matured. However, for weak broadband communication signals in scenarios such as surveillance and communication of small-load UAVs, the existing stochastic resonance detection methods directly use the time-domain energy detection method of narrow-band signals and do not design a special detection method based on the characteristics of broadband signals, so the detection performance is limited under a low signal-to-noise ratio. This study leveraged commonly used broadband communication signals as the research object to meet the detection requirements of weak broadband communication signals. A stochastic resonance signal detection method based on the local spectrum of broadband signals was proposed for single-channel receiving scenarios. Compared to traditional stochastic resonance signal detection methods, the performance of this method was improved by about 6 dB. Secondly, with lower SNR, a two-channel cooperative detection method combining stochastic resonance and cross-correlation detection was proposed, and the system parameter optimization criteria based on the maximization of the mutual relationship between the two channels after stochastic resonance was proposed. Simulation analysis in typical scenarios shows that the local spectrum method can effectively improve the detection performance of weak broadband communication signals with low SNR received by a single channel. For broadband communication signals with lower SNR, dual-channel cross-correlation detection using stochastic resonance processing can further improve detection performance.