针对近场源三维参数估计效率低下及信号源的载波频率估计较少的情况,提出了一种基于均匀圆阵(UCA)的近场源四维参数估计快速算法,利用UCA的中心对称结构构造出两个相关序列,其中一个为利用错位相乘构造的相关序列,使之含有信号源的方位角、俯仰角以及载波的频率信息,而另外一个构造的相关序列则含有信号源的距离参数,这样两个相关序列的相位就包含信号的4-D参数信息.首先对利用错位相乘构造的相关序列利用最小二乘方法给出方位角、俯仰角和频率的估计,然后再利用另一个序列估计出距离参数.仿真结果表明该算法和3-DMUsIC算法性能相当,但由于所提算法无需三维搜索和特征分解,因而计算更加简单利于工程实时实现.
A least squares (LS) algorithm for 4-D parameter estimation was proposed based on a single near-field source impinging on a uniform circular array (UCA). By exploiting the centro-symmetric of the UCA, two correlation sequences were devised. The first one, which contained the azimuth ~- elevation angles, and the carrier frequency information of the source, was constructed via dislocation multiplying method. The second one, which contained range parameter, was directly obtained by the symmetric structure. The azimuth ~ elevation angles and frequency parameters were estimated by the first sequence, and then the unknown range was given from the estimated parameters by the second one. Simulation results indicate that the proposed method has a less the same estimation performance compared with the conventional 3-D MUSIC method, but its computation is more effective.