We consider a single-anchor multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) system with imperfectly synchronized transmitter (Tx) and receiver (Rx) clocks, where the Rx estimates its position based on the received reference signals. The Tx, having (imperfect) prior knowledge about the Rx location and the surrounding geometry, transmits the reference signals based on a set of fixed beams. In this work, we develop strategies for the power allocation among the beams aiming to minimize the expected Cram\'er-Rao lower bound (CRLB) for Rx positioning. Additional constraints on the design are included to ensure that the line-of-sight (LOS) path is detected with high probability. Furthermore, the effect of clock asynchronism on the resulting allocation strategies is also studied. We also propose a gridless compressed sensing-based position estimation algorithm, which exploits the information on the clock offset provided by non-line-of-sight paths, and show that it is asymptotically efficient.

翻译：我们考虑的是单锚多输出多输出输出(MIMO)或直角频率多输出(OFDM)系统,该系统具有不完全同步的发射机(Tx)和接收器(Rx)时钟(OFDM),而Rx根据收到的参考信号估计其位置。Tx(不完全)事先了解Rx的位置和周围几何,根据一套固定的光束传输参考信号。在这项工作中,我们为各梁之间的权力分配制定了战略,目的是最大限度地减少预期的Rx定位的Cram\'er-Rao较低约束(CRLB),包括设计上的其他限制,以确保高概率测出视线路径。此外,还研究了时钟断对所产生分配战略的影响。我们还提议了无网压缩遥感位置估计算法,利用非直线路径提供的时钟抵消信息,并显示它具有微效率。