摘要
针对通信对抗的实际应用,提出了一种在低信噪比下估计跳频信号跳速的方法。首先利用谱图的无交叉干扰项和修正平滑伪Wigner-Vile分布(MSPWD)的强时频聚集性,将谱图和MSPWD进行组合得到了清晰稳健的时频分布;然后基于此分布,利用二次差分法沿着频率轴搜寻每个时间的峰值显示来校正时频矩阵;根据此时频矩阵,分别利用FFT方法、自适应门限法、代价函数法来进行跳频周期估计,仿真结果显示,时频分布经过二次差分处理后,在更低信噪比下提高了估计精度,在跳速较低时,FFT方法在低信噪比时性能较好,在跳速较高时,代价函数法性能较好。
Aimming at the actual application of communcation countermeasures,a method for the hop rate accurate estimation is proposed for the Frequency Hopping（FH） signals.A new time-frequency analysis method,short-time Fourier（STFT）and Modified Smoothed Pesudo WVD（MSPWD） synthesis is proposed,which can obtain robust results with good time-frequency concentration and suppression cross-term interference performance.The peaks of time-equeney distribution are detected based on 2-D（two-dimensional） quadratic diference method.Frequency-hopping signals hop rat estimate can be obtained through FFT method and adaptivet threshold method cost function method.The simulations show that the estimation of hop rate is efficient even if the SNR is low.When low hop rate,FFT method is best;when high hop rate,cost function method is best.
出处
《计算机工程与应用》
CSCD
2012年第3期153-155,共3页
Computer Engineering and Applications
关键词
跳频
时频分析
参数盲估计
frequency hopping
time-frequency analysis
parameter blind estimation
