• CODEBOOK BASED TECHNIQUES FOR HIGH-PERFORMANCE GEOLOCATION

      Yang, Andrew; Goldsworthy, Dylan; Nakamura, Drew; Hua, Lee; Univ California Santa Barbara, Department of Electrical and Computer Engineering (International Foundation for Telemetering, 2018-11)
      Conventional geolocation techniques were developed based on time-delay estimation, followed by computation of the angle of arrival (AOA). The AOA computation is the main cause of latency, which significantly degrades the feasibility of real-time bearing-angle detection. The computation also adds to hardware complexity and power consumption, which is critical for small, light-weight and mobile devices. This paper presents a codebook based approach to geolocation. The delay profiles are mapped to a precomputed codebook to match the optimal estimation of the geolocation. This simplifies the computation procedure and makes real-time computing feasible. It utilizes limited memory capacity to reduce latency and hardware complexity. This approach also allows us to accurately assess the resolving capability. In addition, it reduces computation for joint estimation with multiple receiver units, especially in mobile format.
    • Homing and Docking Algorithms for Circular Transmission and Receiver Arrays

      Radzicki, Vincent R.; Hua, Lee; Univ California Santa Barbara, Department of Electrical and Computer Engineering (International Foundation for Telemetering, 2018-11)
      Homing and docking are two major components in the navigation of UAV’s and UUV’s. It involves the estimation of the six-element displacement vector based on the received signals, where three of the vector elements are associated with the translational displacement and the other three are for the rotation vector. The homing procedure is based on the estimation of the rotation vector with far-field approximations. In the docking range, the displacement estimation becomes more sensitive and critical. Far-field approximation-based algorithms are no longer effective, and high-precision techniques become important and need to be developed. In this paper, we examine and model the multi-dimensional displacement estimation for circular arrays. It allows us to accurately assess the performance as well as the limitation of the algorithms, with respect to various system parameters such as the size of the arrays, range distance, transmitted waveforms, and signal processing algorithms.