Geolocation of multiple noncooperative transmitters using array processing

在这项研究工作的第一阶段(最初的Engage补助金)，研究问题被重新表述为**存在于同一频段的多个非合作发射机的同时地理位置。根据软件定义无线电(SDR)**方法，在设计适当和健壮的算法以及开发相关的**硬件实施以在硬件试验台上进行验证方面都追求这种**功能。多个发射机要求采集站(至少需要2-3个采集站**用于三角定位)配备天线阵列。为了在天线阵列尺寸适中(4-8个单元)的多径丰富的传播环境中以**实用且稳健的方式实现该功能，在阶段1中提出了一个两步过程，并在仿真中进行了验证，包括1-**应用盲源分离(BSS)算法来提取每个发射机的空间签名，以及2-**从每个**空间签名估计主到达方向(DOA)-假设对应于视线。给出每个采集站的DOA估计，三角定位就变得很简单。**在这个提议的第二阶段，两步法及其变体的发展将在**仿真中继续进行，并将在第一步中为BSS算法推导出有效的硬件结构。**此外，还将探索另一种新颖而更简单的方法，它使用与第一步相同的BSS算法，但完全取消了DOA估计，因此不需要阵列校准或特定的阵列**拓扑。在第二阶段的范围内，第二种方法将完全在硬件中实施，并在试验台上进行**验证。

In phase 1 of this research endeavor (original Engage grant) the research problem was reformulated as the**simultaneous geolocation of multiple noncooperative transmitters existing in the same frequency band. This**functionality is pursued both in terms of devising appropriate and robust algorithms, and developing associated**hardware implementations to be validated on a hardware testbed according to a software-defined radio (SDR)**methodology. The plurality of transmitters requires the acquisition stations (at least 2-3 of them being required**for triangulating positions) to be equipped with antenna arrays. In order to implement this functionality in a**manner that is practical and robust in a multipath-rich propagation environment with modest antenna array**sizes (4-8 elements), a two-step process was proposed in phase 1 and validated in simulation consisting of 1-**applying a blind source separation (BSS) algorithm to extract the spatial signature of every transmitter and 2-**estimating the main direction of arrival (DOA) - presumably corresponding to the line of sight - from each**spatial signature. Given a DOA estimate from each acquisition station, triangulating a position becomes trivial.**In this proposed second phase, development of the two-step approach and its variants will continue in**simulation, and an efficient hardware architecture will be derived for the BSS algorithm in the first step.**Furthermore, another novel and simpler approach will be explored which utilizes the same BSS algorithm as a**first step, but does away with DOA estimation altogether, thus not requiring array calibration or a specific array**topology. Within the scope of phase 2, this second approach will be entirely implemented in hardware and**validated on the test bed.