为了合理分配相参增益和空间分集增益在分布式多输入多输出(MIMO)数字阵列雷达系统中的比重,研究了其阵元的优化配置问题。首先,根据MIMO雷达信号模型将阵元配置问题转化为目标散射系数矩阵的分块划分问题;然后,依据子块内信号相参处理,子块间信号非相参处理的方式推导了似然比检测器;最后,分别从检测概率最大、探测距离最远和总的阵元数最少三个方面给出了阵元优化配置的表达式并进行了仿真分析。研究结果表明:应首先利用相参增益将回波信噪比提高到一定值后才能利用空间分集增益;分置接收天线比分置发射天线牺牲的相参增益少;当检测概率大于0.8时,分置两个收发共用的相控阵天线可使系统阵元总数最少,否则无需天线分置。

In order to allocate coherent gain and spatial diversity gain reasonably in the distributed multiple input multiple output (MIMO) digital array radar system, the optimizations of its elements configurations are studied. Firstly, the elements configurations are converted to the block partition of target scattering coefficient matrix according to the MIMO radar signal model. Then the likelihood ratio test detector is derived according to the rules that signals from the same sub-block are processed coherently and signals from different sub-block are processed incoherently. Finally, the formulations for optimal elements configurations are given on the bases of maximum detection probability, maximum detection distance and minimum total element number respectively. And the simulation and analysis about optimal elements configurations are also done. The research results show that the system signal-to-noise ratio should be increased to a certain value before the using of space diversity gain; the lost coherent gain caused by separating receiving antenna is less than that caused by separating transmitting antenna; the total element number of the radar system can be minimized by separating two transceiving phased-array antennas when the detection probability is larger than 0. 8, or else not necessary to separate antennas.

TN958

国家自然科学基金资助项目;中国博士后科学基金资助项目