• CHANNEL AND SPECTRUM ESTIMATION FOR SOFTWARE DEFINED RADIO

      Lee, Hua; Sanchez, Connor D.; Radzicki, Vincent R.; Univ California Santa Barbara, Dept Electrical and Computer Engineering (International Foundation for Telemetering, 2019-10)
      Software defined radios are rapidly increasing in both research and commercial usage for many different applications. As the number of deployed systems increase, a difficult problem that remains is efficient usage of the Radio-Frequency (RF) spectrum to be shared among all these devices. Two key tasks for the radio to perform here include spectral estimation of the RF environment and channel estimation of the communication channel for which the data will be transmitted. These two steps are linked as the communication channel can change over different portions of the RF-spectrum. In this work, an algorithmic approach is presented for passive and active channel estimation procedures for wideband software-defined radios. The algorithm is comprised of first channel quality estimation followed by communication channel planning to optimize the overall performance.
    • DESIGN OF PROBING WAVEFORMS IN SOFTWARE-DEFINED SENSING AND IMAGING SYSTEMS

      Lee, Hua; Univ California Santa Barbara, Dept Electrical and Computer Engineering (International Foundation for Telemetering, 2019-10)
      The probing waveforms play a crucial role in the performance of software-defined sensing-imaging systems. The characteristics of the probing waveforms govern both the computation complexity and accuracy of the estimation. This paper describes the concepts of the design and utilization of the probing waveforms for sensing and imaging applications.
    • LIDAR COLLISION AVOIDANCE SYSTEM WITH AUDIO FEEDBACK FOR VISUALLY IMPARIED INDIVIDUALS

      Lee, Hua; Maravilla, Julian; Shimada, Haruka; Univ California Santa Barbara, Dept Electrical and Computer Engineering (International Foundation for Telemetering, 2019-10)
      In this paper, we present the 4th-generation, light-weight low-power collision avoidance system. For this new version, the ultrasound transmitter of the data-acquisition component is replaced by a Lidar to avoid multi-paths in complex environments. The estimate of the target range is quantized into a frequency bin and represented by acoustic waveforms within the human hearing range. The bearing angle of the target is utilized to produce the temporal offset between the twin channels of the corresponding acoustic waveforms. This wearable and hearable device is designed for real-time navigation for the blind.
    • REMOTE HEART MONITORING VIA MEDICAL TELEMETRY

      Lee, Hua; Radzicki, Vincent R.; Rajagopal, Abhejit; Univ California Santa Barbara, Dept Electrical and Computer Engineering (International Foundation for Telemetering, 2019-10)
      Today, a wide range of heart conditions can be monitored remotely with relatively inexpensive passive sensing technologies, enabling the potential for long-term monitoring and prognosis of patient state under representative environmental stimuli. A medical telemetry system that can incorporate such passive measurements and provide key diagnostic information to medical professionals would provide tremendous value to patients via quantitative and personalized healthcare. This paper presents an overview of passive sensing methods that could be utilized in a medical telemetry system for remote heart monitoring of patients. While active systems are another attractive option, they impose additional constraints on the system that require careful calibration, expert control, and more complex instrumentation. The methods presented here are based on low-cost, sensor technology with the potential to greatly improve long-term non-invasive, heart-health monitoring.
    • THREE-DIMENSIONAL MOTION ESTIMATION AND IMAGE FORMATION WITH ACTIVE ARRAYS

      Lee, Hua; Radzicki, Vincent R.; Univ California Santa Barbara, Dept Electrical and Computer Engineering (International Foundation for Telemetering, 2019-10)
      For target imaging and tracking systems, a key signal processing task is motion estimation. Specifically, the trajectory of a maneuvering target undergoing rigid body motion can be described through a series of translational and rotational transformations. Estimation of these motion parameters provides the tracking system enough information to calculate the targets trajectory over time. Determining the rotational motion to a high accuracy is also very important, as the imaging system can then form an image of the target over multiple aspect angles and thus increase the resolution performance. This paper focuses on algorithm development and performance limitations for motion estimation and image formation using active sensing arrays.