近些年來，隨著通訊技術的發展以及越來越多的室內定位應用的出現，如何高效的實現精確的室內定位變成了一個重要的研究課題。第五代行動通訊網路（5G）被認為是能夠滿足絕大多數室內定位應用需求的一項技術。相較於室外定位，室內定位會受到更大的非直視性測量的影響。並且一些室外定位系統例如全球定位系統，因為嚴重的信號衰減，無法應用於室內環境中。一些典型的室內定位應用包括基於室內位置信息的廣告投放，倉儲和生產線商品的追蹤以及智慧泊車等等。
本文提出了一個基於分散式天線的協同式定位框架來同時定位多個室內設備。其使用到達時間定位技術來確定用戶位置。將定位問題轉化成一個最小化定位誤差的極小化極大優化問題。並將此優化問題轉化成可以使用計算機計算的半正定規劃問題的標準形式。在實驗階段，我們使用了3GPP 提出的室內路徑損耗模型以及ITU 提出的室內可直視概率模型來貼合現實環境。實驗結果也證明了本文提出的方法相較於另外兩個協同式算法能夠實現更低的均方根誤差。

In recent years, with the development of communication technologies and the emergence of indoor positioning applications, how to achieve accurate indoor positioning has become an important research topic. The fifth-generation (5G) cellular networks are expected to accommodate vertical-domain applications that may require precise indoor positioning. Compare to outdoor positioning, indoor positioning suffers from severe non line-of-sight (NLOS) effects. Due to the signal penetration loss, outdoor position systems like GPS can not be adopted for indoor positioning. Typical indoor positioning applications include indoor location-based advertisement, warehouse and assemble line tracking, smart parking, and so on.
This paper proposes a distributed antenna-aided cooperation positioning framework to locate a group of indoor user equipments (UEs) at the same time. The time-of-arrival (TOA) method is adopted. One optimization problem is formulated to minimize the root mean square error (RMSE). In addition, the original minimax problem is transferred into the standard semidefinite programming (SDP) form, which can be solved by convex optimization algorithms. The indoor path loss proposed by 3GPP and LOS path probability models proposed by ITU are used in our simulations. Experimental results show that our proposed approach can outperform two benchmark algorithms in terms of RMSE.

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