# Joint Azimuth, Elevation and Delay Estimation for Single Base Station Localization in 3D IIoT +
###### Abstract  
Integrated sensing and communication (ISAC) in the Industrial Internet of Things (IIoT) presents unique challenges in terms of localization techniques. While three-dimensional (3D) environments offer extra challenges to enhanced accuracy and realism, research in this area remains limited. To bridge this gap, we propose a novel localization technique assisted by a single base station (BS) in 3D IIoT scenarios. Our approach employs the MUltiple SIGNal Classification (MUSIC) algorithm to jointly estimate the angle of arrival (AoA) in azimuth and elevation, as well as the time of arrival (ToA). Compared to conventional multi-BS-assisted or MUSIC-based algorithms, our technique offers flexibility, easy implementation, and low computational cost. To improve performance, we integrate the Taylor-series into the iterative process after a MUSIC-based joint azimuth, elevation angle and delay estimation (JAEDE), resulting in a significant **99**% reduction in computational complexity compared to a two-step MUSIC-based approach utilizing coarse-fine grid searching. Through numerical simulations, we compare our algorithm with three other MUSIC-based joint or separate estimation approaches, demonstrating its superior performance in azimuth angle of arrival (AoAE), elevation angle of arrival (AoAe), TOA, and overall location estimation across varying signal-to-noise ratio (SNR) conditions. s +
Footnote †: This paper is an extended version of our paper published in [PERSON]; [PERSON] “A Portable Base Station Assisted Localization with Grid Bias Elimination”. In Proceedings of the 2023 IEEE Wireless Communications and Networking Conference (WCNC), Glasgow, UK, 26-29 March 2023; pp. 1-6. Footnote †: This paper is an extended version of our paper published in [PERSON]; [PERSON] “A Portable Base Base Station Assisted Localization with Grid Bias Elimination”. In Proceedings of the 2023 IEEE Wireless Communications and Networking Conference (WCNC), Glasgow, UK, 26-2  
conditions for accurate results. High levels of interference and noise in industrial environments negatively impact localization algorithms relying on wireless signals or sound-based techniques. The movement of metallic equipment and materials introduces magnetic field interference, which affects localization methods dependent on magnetic fields. Overcoming these challenges in industrial localization requires specialized solutions and technological advancements. By addressing the challenges of localization in IIoT applications, industries can achieve valuable benefits such as enhanced operational intelligence, improved productivity, and cost savings. Integrating localization with ISAC technologies provides seamless connectivity and real-time control over industrial processes, unlocking the full potential of the IIoT across various sectors [8]. Accurate localization in three dimensions plays a crucial role in IIoT applications, as it provides a more comprehensive understanding of the physical world. Compared to two-dimensional (2D) localization, which only considers horizontal positioning, three-dimensional (3D) localization enables vertical positioning as well. This additional dimension brings about numerous benefits, including enhanced spatial awareness, improved tracking accuracy, and better representation of the real-world environment. Three-dimensional localization offers more precise depth perception, which is particularly valuable in scenarios where vertical positioning is essential, such as multilevel warehouses or construction sites. Moreover, the ability to accurately localize in 3D has been shown to significantly enhance the performance of various IIoT applications [9]. For instance, in logistics and transportation, 3D localization allows for more efficient route planning, load balancing, and collision avoidance. Taking a look at the evolution of modern localization techniques, the advancements in multiple-input multiple-output (MIMO) and multi-carrier technologies make great contributions.