In this work, we study optimal transmit strategies for minimizing the positioning error bound in a line-of-sight scenario, under different levels of prior knowledge of the channel parameters. For the case of perfect prior knowledge, we prove that two beams are optimal, and determine their beam directions and optimal power allocation. For the imperfect prior knowledge case, we compute the optimal power allocation among the beams of a codebook for two different robustness-related objectives, namely average or maximum squared position error bound minimization. Our numerical results show that our low-complexity approach can outperform existing methods that entail higher signaling and computational overhead.

翻译：在这项工作中,我们研究如何在对频道参数的不同认识水平下,在视觉直线情景下最大限度地减少定位误差的最佳传输战略。在对频道参数的不同认识水平下,我们证明两个光束是最佳的,并且决定其光束方向和最佳功率分配。在不完善的先前知识案例中,我们计算了两种不同强度相关目标的代码集之间的最佳功率分配,即平均或最大正方位误差,最小化。我们的数字结果显示,我们低兼容性方法可以优于现有方法,这些方法需要更高的信号和计算间接费用。