为了获得伪码调相与线性调频复合调制探测器抗侦察性能,推导了侦察设备对复合调制信号的侦察作用距离;利用窗口函数原理,建立了参数截获概率模型,给出了参数截获概率随侦察时间变化的数学表达式;从复合调制信号自相关函数的半主瓣宽度得到了复合调制信号的距离截止特性。结果表明,由于探测器的近程工作环境,侦察设备对复合调制探测器的侦察作用距离较小,复合调制信号的参数截获概率远小于单一线性调频和连续波伪码调相信号,且具有尖锐的距离截止特性。对比单一调制方式信号,复合调制信号具有更强的抗截获性能。

A novel combined modulation detector with a combined format of Pseudo-Random-Binary-Phase Code (PRBPC) and Linear Frequency Modulation (LFM) is proposed. Its anti-reconnaissance capability is analyzed from three aspects. The reconnaissance distance for the reconnaissance equipment to scout the combined modulation signal is derived; a model of parameter acquisition probability is established with the help of the window function theory; the expression for the probability of intercept parameters is obtained; the distance cut-off feature of the combined modulation signal is achieved by the half-width of the main lobe of the signal autocorrelation function. The combined modulation waveform is compared to the single LFM signal and the single PRBPC signal during the analysis. The computed results of the three aspects for typical parameters show that the combined modulation detector has a quite large reconnaissance distance due to its short-range working environment, the parameter acquisition of the combined modulation signal is very low, and its distance cut-off feature is very incisive. It is concluded that the combined modulation detector enjoys a strong anti-reconnaissance performance.