深空组阵迭代FX相关合成算法及性能分析

针对火星距离下大规模天线组阵中极微弱接收信号的高效合成问题,在VLBI(Very Long Baseline Interferometry,甚长基线干涉测量)的FX相关器开环处理架构基础上提出了一种新的迭代FX相关合成算法,对算法原理进行了详细理论推导,对数据处理流程、算法合成性能等进行深入分析,与FSC(Full-Spectrum Combining,全频谱合成)、BC(Baseband Combining,基带合成)、SSC(Symbol-Stream Combining,符号流合成)等组阵方案进行性能仿真对比,并给出该算法在36接收天线组阵的实测试验结果。仿真和试验结果表明,迭代FX相关合成算法相比于FSC、BC、SSC等组阵方案具有较好的合成性能,在输入带内信噪比不低于-20d B时,合成效率达到了95%以上,非常适用于火星天线组阵微弱接收信号的组阵合成。

Analysis of the Performance Iterative FX Correlation Combining Algorithm for Arraying in Deep Space Network

In allusion to the problem of the efficient combination of weak receive signal in the antenna arraying at a Martian distance, an iterative FX correlation combining algorithm based on open loop FX correlator in Very Long Baseline Interferometry (VLBI) processing is proposed. The principle of the algorithm are discussed and theoretical derivative, processing flows and performance of the algorithm are analyzed and compared with Full-Spectrum Combining (FSC), Baseband Combining (BC) and Symbol-Stream Combining (SSC) arraying schemes. Experiment results of the iterative FX correlation combining algorithm in the 36 antennas arraying are also given. Simulation and experiment results show the adaptive FX correlation combining algorithm has a better performance than other arraying methods such as FSC, BC and SSC. Combining efficiency of the proposed algorithm is better than 95% when the Signal to Noise Ratio (SNR) of received signal of single antenna is no below -20 dB, and is acceptable for arraying combining of weaker received signal at Martian distance.