基于时频分析的雷达信号到达角估计

Direction-of-arrival estimation of radar signals based on time-frequency analysis

现有的空间时频分布(STFD)的信号表示只适用于窄带、连续信号的分析,而雷达侦察系统要求对脉冲、线性调频等信号同时进行到达角(DOA)、频率和信号时域参数的估计。本文给出了现有空间时频分布对雷达信号DOA估计的条件,并提出了基于修正STFD矩阵的DOA估计算法。通过对各阵元输出作时频分析,估计信号的频率参数,然后据此构造方向向量和修正STFD矩阵,即可构造MUSIC空间谱。该算法不受基于现有STFD算法的条件限制。

Traditional spatial time-frequency distribution (STFD) matrices is only suitable to be applied to narrow- band signals, but in electronic warfare receiver systems, it is required to estimate the three dimensional parameters of wideband pulse signals such as direction-of-arrival (DOA), radio frequency (RF) and time domain parameters of incoming signals. In order to apply the STFD matrices to wideband or spread spectrum signal, a modified algorithm to estimate DOA is presented. With the time-frequency analysis of array output signals, the relationship between frequency and time can be achieved. Accordingly the steering vector and modified STFD matrices is constructed by the frequency information. Finally, the MUSIC spectrum can be derived to estimate the DOA of signals.