Accurate node localization is vital for mobile ad hoc networks (MANETs). Current methods like Time of Arrival (TOA) can estimate node positions using imprecise baseplates and achieve the Cram\'er-Rao lower bound (CRLB) accuracy. In multi-hop MANETs, some nodes lack direct links to base anchors, depending on neighbor nodes as dynamic anchors for chain localization. However, the dynamic nature of MANETs challenges TOA's robustness due to the availability and accuracy of base anchors, coupled with ranging errors. To address the issue of cascading positioning error divergence, we first derive the CRLB for any primary node in MANETs as a metric to tackle localization error in cascading scenarios. Second, we propose an advanced two-step TOA method based on CRLB which is able to approximate target node's CRLB with only local neighbor information. Finally, simulation results confirm the robustness of our algorithm, achieving CRLB-level accuracy for small ranging errors and maintaining precision for larger errors compared to existing TOA methods.

翻译：准确的节点定位对移动自组织网络(MANET)至关重要。现有方法如到达时间(TOA)可利用不精确基板估计节点位置，并达到克拉美-罗下界(CRLB)精度。在多跳MANET中，部分节点缺乏与基锚的直接链路，需依赖邻节点作为动态锚节点进行链式定位。然而，MANET的动态特性因基锚的可用性与精度差异，结合测距误差，对TOA的鲁棒性构成挑战。为解决级联定位误差发散问题，我们首先推导MANET中任意主节点的CRLB，作为衡量级联场景下定位误差的指标。其次，提出一种基于CRLB的高级两步TOA方法，该方法仅利用局部邻域信息即可逼近目标节点的CRLB。最后，仿真结果证实了算法鲁棒性：与现有TOA方法相比，本算法在测距误差较小时可实现CRLB级精度，并能在测距误差较大时保持定位精度。