Now showing items 401-420 of 1830

  • Directional Antenna Diversity for Mobile Devices: Characterizations and Solutions 

    Amiri Sani, Ardalan (2011)
    We report a first-of-its-kind realization of directional transmission for smartphone-like mobile devices using multiple passive directional antennas, supported by only one RF chain. The key is a multi-antenna system (MiDAS) ...
  • Directional Complex-Wavelet Processing 

    Fernandes, Felix; van Spaendonck, Rutger; Burrus, C. Sidney (2000-08-20)
    Poor directional selectivity, a major disadvantage of the separable 2D discrete wavelet transform (DWT), has previously been circumvented either by using highly redundant, nonseparable wavelet transforms or by using ...
  • Directional Hypercomplex Wavelets for Multidimensional Signal Analysis and Processing 

    Chan, Wai Lam; Choi, Hyeokho; Baraniuk, Richard G. (2004-05-01)
    We extend the wavelet transform to handle multidimensional signals that are smooth save for singularities along lower-dimensional manifolds. We first generalize the complex wavelet transform to higher dimensions using a ...
  • Directional Scale Analysis for Seismic Interpretation 

    van Spaendonck, Rutger; Baraniuk, Richard G. (1999-11-01)
    A combined space-Fourier representation focused on directional scale analysis is presented. The method leads to a space-log polar frequency distribution. Application to seismic data shows differentiation in scale and ...
  • Directional, Shift-Insensitive, Complex Wavelet Transforms with Controllable Redundancy 

    Fernandes, Felix (2001-08-20)
    Although the Discrete Wavelet Transform (DWT) is a powerful tool for signal and image processing, it has three serious disadvantages. First, the DWT is shift sensitive because input-signal shifts generate unpredictable ...
  • Discovery of optimal zeolites for challenging separations and chemical transformations using predictive materials modeling 

    Bai, Peng; Jeon, Mi Yeong; Ren, Limin; Knight, Chris; Deem, Michael W.; Tsapatsis, Michael; Siepmann, J. Ilja (2015)
    Zeolites play numerous important roles in modern petroleum refineries and have the potential to advance the production of fuels and chemical feedstocks from renewable resources. The performance of a zeolite as separation ...
  • Discrete finite variation: A new measure of smoothness for the design of wavelet basis 

    Odegard, Jan E.; Burrus, C. Sidney (1996-05-20)
    A new method for measuring and designing smooth wavelet basis which dispenses with the need for having a large number of zero moments of the wavelet is given. The method is based on minimizing the "discrete finite variation", ...
  • Discrete-time linear periodically time-varying systems: Analysis, realization and model reduction 

    Hu, Jing (2003)
    Discrete-time linear periodically time-varying (LPTV) systems, considered as a bridge between the well-studied linear time-invariant (LTI) model and the nonlinear time-varying problems in real world, have been receiving ...
  • Displacement MIMO Kalman equalizer architecture for CDMA downlink in fast fading channels 

    Guo, Yuanbin; Zhang, Jianzhong (Charlie); McCain, Dennis; Cavallaro, Joseph R. (2005-07-01)
    In this paper, we explore the displacement structure in a Kalman equalizer for MIMO-CDMA downlink. A streamlined MIMO Kalman equalizer architecture is proposed to extract the commonality in the data path by exploiting the ...
  • Displacement MIMO Kalman Equalizer for CDMA Downlink in Fast Fading Channels 

    Guo, Yuanbin; Zhang, Jianzhong (Charlie); McCain, Dennis; Cavallaro, Joseph R. (2005-11-01)
    In this paper, a streamlined MIMO Kalman equalizer architecture is proposed to extract the commonality in the data path by jointly considering the displacement structure of the transition matrix and the block-Toeplitz ...
  • Distorted Channel Capacity: A Geometrical Approach 

    Das, Suman; Cavallaro, Joseph R.; Erkip, Elza; Aazhang, Behnaam (2000-06-20)
    Shannon's capacity result has often been used as a benchmark to compare the performance of practical codes. Shannon's theorem helps us to calculate the maximum rate at which data can be transferred without making any errors. ...
  • Distributed alternating localization-triangulation of camera networks 

    Mantzel, William E. (2005)
    Localization, estimating the positions and orientations of a set of camera nodes, is a critical first step in camera-based sensor network applications such as geometric estimation and scene reconstruction. We propose a ...
  • Distributed Camera Network Localization 

    Mantzel, William; Choi, Hyeokho; Baraniuk, Richard G. (2004-11-01)
    Localization, estimating the positions and orientations of a set of cameras, is a critical first step in camera-based sensor network applications such as geometric estimation, scene reconstruction, and motion tracking. We ...
  • Distributed Compressed Sensing of Jointly Sparse Signals 

    Sarvotham, Shriram; Baron, Dror; Wakin, Michael; Duarte, Marco F.; Baraniuk, Richard G. (2005-11-01)
    Compressed sensing is an emerging field based on the revelation that a small collection of linear projections of a sparse signal contains enough information for reconstruction. In this paper we expand our theory for ...
  • Distributed Cooperative Communications in Wireless Networks 

    Khojastepour, Mohammad (2005-01-01)
    The primary challenge in communication over wireless networks, unlike wireline networks, is the existence of interference and channel variations (fading). Having more users at higher data rates means that current ...
  • Distributed cooperative communications in wireless networks 

    Khojastepour, Mohammad Ali (2004)
    The primary challenge in wireless networks, unlike wireline networks, is the existence of interference and channel variations (fading). Having more users at higher data rates means that current point-to-point networks will ...
  • Distributed Decoding in Cooperative Communications 

    Karkooti, Marjan; Cavallaro, Joseph R. (2007-11-01)
    In this paper, we present a novel relaying strategy called distributed and partial decoding. This strategy can be viewed as a variation of the decode and forward with the difference that the relay partially decodes the ...
  • Distributed Image Compression for Sensor Networks using Correspondence Analysis and Super-Resolution 

    Wagner, Raymond; Nowak, Robert David; Baraniuk, Richard G. (2003-09-01)
    We outline a distributed coding technique for images captured from sensors with overlapping fields of view in a sensor network. First, images from correlated views are roughly registered (relative to a sensor of primary ...
  • Distributed image compression in camera networks 

    Wagner, Raymond S. (2004)
    Dense networks of wireless, battery-powered sensors are now feasible thanks to recent hardware advances, but key issues such as power consumption plague widespread deployment. Fortunately, in a dense network of sensors, ...
  • Distributed Image Compression in Camera Networks 

    Wagner, Raymond (2004-05-01)
    Dense networks of wireless, battery-powered sensors are now feasible thanks to recent hardware advances, but key issues such as power consumption plague widespread deployment. Fortunately, in a dense network of sensors, ...