Now showing items 331-350 of 1107

    • Fermi-edge superfluorescence from a quantum-degenerate electron-hole gas 

      Kim, Ji-Hee; Noe, G. Timothy II; McGill, Stephen A.; Wang, Yongrui; Wojcik, Aleksander K.; Belyanin, Alexey A.; Kono, Junichiro (2013)
      Nonequilibrium can be a source of order. This rather counterintuitive statement has been proven to be true through a variety of fluctuation-driven, self-organization behaviors exhibited by out-of-equilibrium, many-body ...
    • FFT-Accelerated Iterative MIMO Chip Equalizer Architecture For CDMA Downlink 

      Guo, Yuanbin; McCain, Dennis; Cavallaro, Joseph R. (2005-03-01)
      In this paper, we present a novel FFT-accelerated iterative Linear MMSE chip equalizer in the MIMO CDMA downlink receiver. The reversed form time-domain matrix multiplication in the Conjugate Gradient iteration is accelerated ...
    • Finite Backlog Effects on Downlink Scheduling 

      Ahmed, Nasir; Khojastepour, Mohammad; Sabharwal, Ashutosh; Aazhang, Behnaam (2003-11-20)
      In a multi-user downlink system, the use of channel estimates in the scheduling process can significantly improve the spectral efficiency. Recent work has shown that from a sum rate capacity standpoint, and assuming infinite ...
    • Finite Memory-length Linear Multiuser detection for Asyncchronous Communications 

      Juntti, Markku J.; Aazhang, Behnaam (1997-05-20)
      Decorrelating, linear, minimum mean-squared error (LMMSE), and noise-whitening multiuser detectors for code-division multiple-access systems (CDMA) are ideally infinite memory-length (referred to as IIR) detectors. To ...
    • Finite memory-length linear multiuser detection for asynchronous CDMA communications 

      Juntti, Markku J.; Aazhang, Behnaam (1997-10-20)
      Decorrelating, linear, minimum mean-squared error (LMMSE), and noise-whitening multiuser detectors for code-division multiple-access systems (CDMA) are ideally infinite memory-length (referred to as IIR) detectors. To ...
    • Finite Rate Feedback Design for Multiple Transmit Antennas 

      Mukkavilli, Krishna Kiran; Sabharwal, Ashutosh; Aazhang, Behnaam (2002-10-20)
      Many practical systems employ a feedback channel to convey the channel state information to the transmitter.The capacity of the feedback channels is usually limited to a few bits per frame. We design feedback based ...
    • Fixed Point Error Analysis Of Multiuser Detection and Synchronization Algorithms For CDMA Communication Systems 

      Sengupta, Chaitali; Das, Suman; Cavallaro, Joseph R.; Aazhang, Behnaam (1998-04-20)
      Conventional correlation based single-user techniques for Direct Sequence Code Division Multiple Access (DS-CDMA) wireless communication systems are susceptible to performance degradation due to interference from other ...
    • Flex-Sphere: An FPGA Configurable Sort-Free Sphere Detector For Multi-user MIMO Wireless Systems 

      Amiri, Kiarash; Dick, Chris; Rao, Raghu; Cavallaro, Joseph R. (2008-10-01)
      Spatial division multiplexing (SDM) in MIMO technology significantly increases the spectral efficiency, and hence capacity, of a wireless communication system: it is a core component of the next generation wireless systems, ...
    • A Flexible and Efficient Application Programming Interface (API) for a Customizable Proxy Cache 

      Pai, Vivek S.; Cox, Alan; Pai, Vijay S.; Zwaenepoel, Willy (2003-03-20)
      This paper describes the design, implementation, and performance of a simple yet powerful Application Programming Interface (API) for providing extended services in a proxy cache. This API facilitates the development of ...
    • A Flexible LDPC/Turbo Decoder Architecture 

      Sun, Yang; Cavallaro, Joseph R. (2011-07-01)
      Low-density parity-check (LDPC) codes and convolutional Turbo codes are two of the most powerful error correcting codes that are widely used in modern communication systems. In a multi-mode baseband receiver, both LDPC ...
    • Flexible N-Way MIMO Detector on GPU 

      Wu, Michael; Yin, Bei; Cavallaro, Joseph R. (2012-10-17)
      This paper proposes a flexible Multiple-Input Multiple-Output (MIMO) detector on graphics processing units (GPU). MIMO detection is a key technology in broadband wireless system such as LTE,WiMAX, and 802.11n. Existing ...
    • Flexible Wavelet Transforms Using Lifting 

      Claypoole, Roger L.; Baraniuk, Richard G. (1998-09-01)
      We introduce and discuss biorthogonal wavelet transforms using the lifting construction. The lifting construction exploits a spatial-domain, prediction-error interpretation of the wavelet transform and provides a powerful ...
    • Floating-Point CORDIC for Matrix Computations 

      Cavallaro, Joseph R.; Luk, Franklin T. (1988-10-01)
      The CORDIC algorithms provide a VLSI hardware technique for computing the inverse tangents and vector rotations needed by many matrix decomposition algorithms. Although normally stated for fixed-point arithmetic, the CORDIC ...
    • Focused terahertz waves generated by a phase velocity gradient in a parallel-plate waveguide 

      McKinney, Robert W.; Monnai, Yasuaki; Mendis, Rajind; Mittleman, Daniel (2015)
      We demonstrate the focusing of a free-space THz beam emerging from a leaky parallel-plate waveguide (PPWG). Focusing is accomplished by grading the launch angle of the leaky wave using a PPWG with gradient plate separation. ...
    • ForWaRD: Fourier-Wavelet Regularized Deconvolution for Ill-Conditioned Systems 

      Neelamani, Ramesh; Choi, Hyeokho; Baraniuk, Richard G. (2004-02-01)
      We propose an efficient, hybrid <i>Fourier-Wavelet Regularized Deconvolution</i> (ForWaRD) algorithm that performs noise regularization via scalar shrinkage in both the Fourier and wavelet domains. The Fourier shrinkage ...
    • Four top reasons why mutual information does not assess neural information processing 

      Johnson, Don (2002-07-20)
      Mutual information between stimulus and response has been advocated as an information theoretic measure of a neural system's capability to process information. Once calculated, the result is a single number that supposedly ...
    • A Fourier-Prony Tauberian Approach to the Analysis of a Mixture of Delayed Signals 

      de Figueiredo, Rui J.P.; Hu, C.L. (1979-09-20)
      Let x and y be signals (i.e. real-valued functions of time) of finite duration and energy. In the present paper, we develop a frequency domain Prony approach for interpolating, or in general, approximating y(t) by ....
    • An FPGA Based Rapid Prototyping Platform for MIMO Systems 

      Murphy, Patrick; Lou, Feifei; Sabharwal, Ashutosh; Frantz, Patrick (2003-11-20)
      There exists a seemingly limitless demand for wireless communications systems capable of higher datarates with lower power consumption. While the demand for improvement in these systems seems limitless, the spectrum ...
    • An FPGA Implementation Of Alamouti's Transmit Diversity Technique 

      Murphy, Patrick; Frantz, Patrick; Dick, Chris (2003-10-01)
      This paper presents the FPGA implementation of a multiple antenna wireless communications system based on Alamouti's transmit diversity scheme. Alamouti's transmit diversty scheme is a space-time block code with support ...
    • FPGA Implementation of Dynamic Threshold Sphere Detection for MIMO Systems 

      Amiri, Kiarash; Cavallaro, Joseph R. (2006-11-01)
      In this paper, we consider the FPGA implementation of a modified sphere detection algorithm. We analyze breadth-first and depth-first search in sphere detection, and compare the relative performance and complexity. Based ...