针对多输入多输出雷达所采用的正交四相编码信号,提出了基于循环自相关函数的参数估计方法。文中首先对正交四相编码信号模型的循环自相关函数和循环谱密度函数进行了推导;然后,依据推导结果,通过对循环谱密度函数最大模值位置的搜索完成了对信号载频的估计;最后,对不同延时条件下循环自相关函数在相位修正后进行累积,实现了对码速率的估计。仿真表明,文中算法在信噪比优于1 dB 后,可以较好地完成对正交四相编码信号的调制参数估计。

Based on cyclic autocorrelation, a method of parameters estimation for orthogonal QPSK signal used by MIMO radar is proposed in this paper. Firstly, cyclic autocorrelation function and cyclic spectrum density of orthogonal QPSK signal are deduced. According to the deduction, estimation of carrier frequency is accomplished through searching the cyclic spectrum density for the location of the maximal value. Then, cyclic autocorrelation functions of different time delay are accumulated to complete estimation of code frequency. Simulation results verify that the proposed method could achieve accurate parameters estimation when SNR is better than 1 dB.

TN957

国家自然科学基金资助项目