Now showing items 1-60 of 268

  • 802.11b Operating in a Mobile Channel: Performance and Challenges 

    Steger, Christopher; Radosavljevic, Predrag; Frantz, Patrick (2003-09-20)
    In the past, the worlds of wireless voice and data transmission have been largely disjoint. Voice traffic has been carried over circuit-switched cellular links, and data has been largely restricted to packet-switched ...
  • Adaptive Fault Detection and Tolerance for Robots 

    Visinsky, Monica L.; Cavallaro, Joseph R.; Walker, Ian D. (1994-08-01)
    In existing robot fault detection schemes, sensed values of the joint status (position, velocity, etc.) are typically compared against expected or desired values, and if a given threshold is exceeded, a fault is inferred. ...
  • Advanced MIMO-CDMA Receiver for Interference Suppression: Algorithms, System-on-Chip Architectures and Design Methodology 

    Guo, Yuanbin (2005-05-01)
    MIMO (Multiple Input Multiple Output) technology is proposed in CDMA systems for much higher rate packet services. The receiver architecture is essential for the mobile devices to support high speed multimedia service. ...
  • Advanced Techniques for Next-Generation Wireless Systems 

    Sendonaris, Andrew (1999-08-20)
    In order to meet the demands of next-generation wireless systems, which will be required to support multirate multimedia at high data rates, it is necessary to employ advanced algorithms and techniques that enable the ...
  • Analysis of Robots for Hazardous Environments 

    Harpel, Barbara McLaughlin; Dugan, Joanne Bechta; Walker, Ian D.; Cavallaro, Joseph R. (1997-01-01)
    Reliability analysis of fault tolerant systems often ignores the small probability that a failure might not be detected or, if detected, may not be properly handled. The probability that the failure is detected and properly ...
  • Analyzing Dynamics and Stimulus Feature Dependence in the Information Processing of Crayfish Sustaining Fibers 

    Rozell, Chris (2002-04-20)
    The sustaining fiber (SF) stage of the crayfish visual system converts analog stimulus representations to spike train signals. A recent theory quantifies a system's information processing capabilities and relates to ...
  • Antenna Arrays for Wireless CDMA Communication Systems 

    Madyastha, Raghu (1997-05-20)
    The estimation of code delays along with amplitudes and phases of different users constitutes the first stage in the demodulation process in a CDMA communication system. The delay estimation stage is termed the acquisition ...
  • Application-Specific Accelerators for Communications 

    Sun, Yang; Amiri, Kiarash; Brogioli, Michael; Cavallaro, Joseph R. (2010-01-01)
    For computation-intensive digital signal processing algorithms, complexity is exceeding the processing capabilities of general-purpose digital signal processors (DSPs). In some of these applications, DSP hardware accelerators ...
  • Architecture and Algorithm for a Stochastic Soft-output MIMO Detector 

    Amiri, Kiarash; Radosavljevic, Predrag; Cavallaro, Joseph R. (2007-11-04)
    In this paper, we propose a novel architecture for a soft-output stochastic detector in multiple-input, multiple-output (MIMO) systems. The stochastic properties of this detector are studied and derived in this work, ...
  • Architecture and Algorithm for a Stochastic Soft-output MIMO Detector 

    Amiri, Kiarash; Radosavljevic, Predrag; Cavallaro, Joseph R. (2007-11-01)
    In this paper, we propose a novel architecture for a soft-output stochastic detector in multiple-input, multiple-output (MIMO) systems. The stochastic properties of this detector are studied and derived in this work, and ...
  • Architecture and Algorithms for Scalable Mobile QoS 

    Sadeghi, Bahareh (2000-04-20)
    We develop a simple analytical model to study the system and illustrate several key components of the approach. We formulate the problem of how to group the cells to form the virtual system as an optimization problem and ...
  • ARCHITECTURE DESIGN AND IMPLEMENTATION OF THE INCREASING RADIUS - LIST SPHERE DETECTOR ALGORITHM 

    Myllylä, Markus; Juntti, Markku; Cavallaro, Joseph R. (2009-04-01)
    A list sphere detector (LSD) is an enhancement of a sphere detector (SD) that can be used to approximate the optimal MAP detector. In this paper, we introduce a novel architecture for the increasing radius (IR)-LSD algorithm, ...
  • Architecture Design and Implementation of the Metric First List Sphere Detector Algorithm 

    Myllylä, Markus; Cavallaro, Joseph R.; Juntti, Markku (2011-05-01)
    Soft-output detection of a multiple-input–multiple-output (MIMO) signal pose a significant challenge in future wireless systems. In this paper, we introduce a soft-output modified metric first (MMF)-LSD algorithm for MIMO ...
  • Architectures for Cognitive Radio Testbeds and Demonstrators – An Overview 

    Gustafsson, Oscar; Amiri, Kiarash; Andersson, Dennis; Blad, Anton; Bonner, Christian; Cavallaro, Joseph R.; Declerck, Jeroen; Dejonghe, Antoine; Eliardsson, Patrik; Glasse, Miguel; Hayar, Aawatif; Hollevoet, Lieven; Hunter, Chris; Joshi, Madhura; Kaltenberger, Florian; Knopp, Raymond; Le, Khanh; Miljanic, Zoran; Murphy, Patrick; Naessens, Frederik; Nikaein, Navid; Nussbaum, Dominique; Pacalet, Renaud; Raghavan, Praveen; Sabharwal, Ashutosh; Sarode, Onkar; Spasojevic, Predrag; Sun, Yang; Tullberg, Hugo M.; Vander Aa, Tom; Van der Perre, Liesbet; Wetterwald, Michelle; Wu, Michael (2010-06-01)
    Wireless communication standards are developed at an ever-increasing rate of pace, and significant amounts of effort is put into research for new communication methods and concepts. On the physical layer, such topics include ...
  • Architectures for Heterogeneous Multi-Tier Networks 

    Cavallaro, Joseph R. (2002-01-15)
    Next-generation wireless computing platforms will contain flexible communications capabilites. At Rice University, the Rice Everywhere NEtwork (RENE) project is investigating a multi-standard, multi-tier integration of ...
  • Arithmetic Acceleration Techniques for Wireless Communication Receivers 

    Das, Suman; Rajagopal, Sridhar; Sengupta, Chaitali; Cavallaro, Joseph R. (1999-10-20)
    We develop techniques to accelerate the implementation of the next generation wireless communication algorithms in hardware. We discuss an implementation of a key computationally intensive baseband algorithm for joint ...
  • ASIC Implementation Comparison of SIC and LSD Receivers for MIMO-OFDM 

    Ketonen, Johanna; Myllylä, Markus; Juntti, Markku; Cavallaro, Joseph R. (2008-10-01)
    MIMO-OFDM receivers with horizontal encoding are considered in this paper. The successive interference cancellation (SIC) algorithm is compared to the K-best list sphere detector (LSD). A modification to the K-best LSD ...
  • Automated Evaluation of Critical Features in VLSI Layouts Based on Photolithographic Simulations 

    Sengupta, Chaitali; Cavallaro, Joseph R.; Wilson, William L.; Tittel, Frank K. (1997-11-01)
    In this paper, we address the problem of identifying and evaluating “critical features” in an integrated circuit (IC) layout. The “critical features” (e.g., nested elbows and open ends) are areas in the layout that are ...
  • Automated Evaluation of Critical Features in VLSI Layouts Based on Photolithographic Simulations 

    Cavallaro, Joseph R.; Sengupta, Chaitali; Tittel, Frank K.; Wilson, William L. Jr. (1996-01-01)
    This paper describes a CAD tool (An Integrated CAD Framework) which links VLSI layout editors to lithographic simulators and provides information on the simulated resolution of a feature to the circuit designer. The designer ...
  • Baseband Architecture Design for Future Wireless Base-Station Receivers 

    Rajagopal, Sridhar (2000-05-20)
    This thesis demonstrates designing efficient algorithms and architectures to meet the real-time requirements of future wireless base-station receivers. Next generation receivers require orders-of-magnitude performance ...
  • A bit-streaming pipelined multiuser detector for wireless communications 

    Rajagopal, Sridhar; Cavallaro, Joseph R. (2001-05-20)
    This paper presents a bit-streaming, pipelined and reduced complexity architecture to meet real-time requirements for asynchronous multiuser detection in wireless communication CDMA receivers. Typically, asynchronous ...
  • Coding-Spreading Tradeoff for Lattice Codes 

    Khoshnevis, Ahmad (2001-04-20)
    A fixed bandwidth expansion can be achieved either by coding or spreading, while each have different effect on the resultant signal space. Coding increases both Shannon and Fourier bandwidth whereas spreading only increases ...
  • Communication Processors 

    Rajagopal, Sridhar; Cavallaro, Joseph R. (2005-07-01)
    Communication processors are processors with specific optimizations to support communication sys-tems. Communication processors exist in a wide variety of forms and can be categorized based on the communication system, ...
  • Compact Hardware Accelerator for Functional Verification and Rapid Prototyping of 4G Wireless Communication Systems 

    Guo, Yuanbin; McCain, Dennis (2004-11-01)
    In this paper, we propose an FPGA-based hardware accelerator platform with Xilinx Virtex-II V3000 in a compact PCMCIA form factor. By partitioning the complex algorithms in the 4G simulator to the hardware accelerator, ...
  • COMPARISON OF TWO NOVEL LIST SPHERE DETECTOR ALGORITHMS FOR MIMO-OFDM SYSTEMS 

    Myllylä, Markus; Silvola, Pirkka; Juntti, Markku; Cavallaro, Joseph R. (2006-09-01)
    In this paper, the complexity and performance of two novel list sphere detector (LSD) algorithms are studied and evaluated in multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) system. ...
  • Compiler Driven Architecture Design Space Exploration for DSP Workloads: A Study in Software Programmability Versus Hardware Acceleration 

    Brogioli, Michael C.; Cavallaro, Joseph R. (2009-11-01)
    Wireless communications and video kernels contain vast instruction and data level parallelism that can far outstrip programmable high performance DSPs. Hardware acceleration of these bottlenecks is commonly done at the ...
  • Complexity Analysis of MMSE Detector Architectures for MIMO OFDM Systems 

    Myllylä, Markus; Hintikka, Juha-Matti; Cavallaro, Joseph R.; Juntti, Markku; Limingoja, Matti; Byman, Aaron (2005-11-01)
    In this paper, a field programmable gate array (FPGA) implementation of a linear minimum mean square error (LMMSE) detector is considered for MIMO-OFDM systems. Two square root free algorithms based on QR decomposition ...
  • Configurable and Scalable High Throughput Turbo Decoder Architecture for Multiple 4GWireless Standards 

    Sun, Yang; Zhu, Yuming; Goel, Manish; Cavallaro, Joseph R. (2008-07-01)
    In this paper, we propose a novel multi-code turbo decoder architecture for 4G wireless systems. To support various 4G standards, a configurable multi-mode MAP (maximum a posteriori) decoder is designed for both binary and ...
  • Configurable and Scalable Turbo Decoder for 4G Wireless Receivers 

    Sun, Yang; Cavallaro, Joseph R.; Zhu, Yuming; Manish, Goel (2010-01-01)
    The increasing requirements of high data rates and quality of service (QoS) in fourth-generation (4G) wireless communication require the implementation of practical capacity approaching codes. In this chapter, the application ...
  • Configurable LDPC Decoder Architecture for Regular and Irregular Codes 

    Karkooti, Marjan; Radosavljevic, Predrag; Cavallaro, Joseph R. (2008-11-01)
    Low Density Parity Check (LDPC) codes are one of the best error correcting codes that enable the future generations of wireless devices to achieve higher data rates with excellent quality of service. This paper presents ...
  • Cooperative Partial Detection Using MIMO Relays 

    Amiri, Kiarash; Wu, Michael; Cavallaro, Joseph R.; Lilleberg, Jorma (2011-10-01)
    Using multiple-input multiple-output (MIMO) relays in cooperative communication improves the data rate and reliability of the communication. The MIMO transmission, however, requires considerable resources for the detection ...
  • CORDIC Arithmetic for an SVD Processor 

    Cavallaro, Joseph R.; Luk, Franklin T. (1987-05-01)
    Arithmetic issues in the calculation of the Singular Value Decomposition (SVD) are discussed. Traditional algorithms using hardware division and square root are replaced with the special purpose CORDIC algorithms for ...
  • CORDIC Arithmetic for an SVD Processor 

    Cavallaro, Joseph R.; Luk, Franklin T. (1988-06-20)
    Arithmetic issues in the calculation of the Singular Value Decomposition (SVD) are discussed. Traditional algorithms using hardware division and square root are replaced with the special purpose CORDIC algorithms for ...
  • Data Collection by a Mobile Observer in a Single-hop Sensor Network 

    Chakrabarti, Arnab; Sabharwal, Ashutosh; Aazhang, Behnaam (2005-01-15)
    In this paper, we demonstrate significant reduction in communication power by using a mobile observer to collect data from a wireless single-hop network of static sensors. The key challenge in using a mobile observer is ...
  • Data-parallel Digital Signal Processors: Algorithm Mapping, Architecture Scaling and Workload Adaptation 

    Rajagopal, Sridhar (2004-05-01)
    Emerging applications such as high definition television (HDTV), streaming video, image processing in embedded applications and signal processing in high-speed wireless communications are driving a need for high performance ...
  • Dataflow Modeling and Design for Cognitive Radio Networks 

    Wang, Lai-Huei; Bhattacharyya, Shuvra S.; Vosoughi, Aida; Cavallaro, Joseph R.; Juntti, Markku; Boutellier, Jani; Silven, Olli; Valkama, Mikko (2013-10-01)
    Cognitive radio networks present challenges at many levels of design including configuration, control, and crosslayer optimization. In this paper, we focus primarily on dataflow representations to enable flexibility and ...
  • Decision-Directed Channel Estimation Implementation for Spectral Efficiency Improvement in Mobile MIMO-OFDM 

    Ketonen, Johanna; Juntti, Markku; Ylioinas, Jari; Cavallaro, Joseph R. (2013-09-30)
    Channel estimation algorithms and their implementations for mobile receivers are considered in this paper. The 3GPP long term evolution (LTE) based pilot structure is used as a benchmark in a multiple-input multiple-o ...
  • Delay and Rate Constrained Transmission Policies over Wireless Channels 

    Rajan, Dinesh; Sabharwal, Ashutosh; Aazhang, Behnaam (2001-11-20)
    In this paper, we study delay and rate-constrained transmission of bursty traffic over wireless channels. We characterize the minimum power requirements via bounds for both single user and multiuser downlink problems, using ...
  • Delay-constrained Scheduling: Power Efficiency, Filter Design, and Bounds 

    Khojastepour, Mohammad; Sabharwal, Ashutosh (2004-03-01)
    In this paper, packet scheduling with maximum delay constraints is considered with the objective to minimize average transmit power over Gaussian channels. The main emphasis is on deriving robust schedulers which do ...
  • Design and Analysis of Heterogeneous DSP/FPGA Based Architectures for 3GPP Wireless Systems 

    Brogioli, Michael C.; Gadhiok, Manik; Cavallaro, Joseph R. (2006-04-01)
    This paper shows how iterative hardware/software partitioning in heterogeneous DSP/FPGA based embedded systems can be utilized to achieve real-time deadlines of modern 3GPP wireless equalization workloads. By utilizing a ...
  • Design and Architecture of Spatial Multiplexing MIMO Decoders for FPGAs 

    Dick, Chris; Amiri, Kiarash; Cavallaro, Joseph R.; Rao, Raghu (2008-10-01)
    Spatial multiplexing multiple-input-multiple-output (MIMO) communication systems have recently drawn significant attention as a means to achieve tremendous gains in wireless system capacity and link reliability. The optimal ...
  • Design space exploration for real-time embedded stream processors 

    Rajagopal, Sridhar; Cavallaro, Joseph R.; Rixner, Scott (2004-07-01)
    We present a design framework for rapidly exploring the design space for stream processors in real-time embedded systems. Stream processors enable hundreds of arithmetic units in programmable pro-cessors by using clusters ...
  • Development of Digital Signal Processor controlled Quantum Cascade Laser based Trace Gas Sensor Technology 

    So, Stephen; Wysocki, Gerard; Frantz, Patrick; Tittel, Frank K. (2006-08-01)
    This work reports the design and integration of a custom digital signal processor (DSP) system into a pulsed quantum cascade laser (QCL) based trace gas sensor to improve its portability, robustness and operating performance. ...
  • Development of Japanese-language DSP Education Content in the Connexions Project 

    Frantz, Patrick; Yamada, Yoji (2005-10-01)
    Due to factors such as a small and fragmented market and rapid hardware development, the conventional textbook is inadequate for DSP lab education. Freely available open-content materials that enable and promote local ...
  • 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 ...
  • 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 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 ...
  • DSP Education At Rice University 

    Frantz, Patrick; Choi, Hyeokho; Baraniuk, Richard G. (2003-09-01)
    Rice University has a decades-long tradition of both digital signal processing (DSP) research and education, beginning in 1968. Since that time, Rice University has become a world leader and continued to be a pioneer in ...
  • A DSP-Based Platform for Wireless Video Compression 

    Murphy, Patrick; Bharadwaj, Vinay; Welsh, Erik; Frantz, Patrick (2002-11-01)
    With the exponential growth of wireless voice markets, demand for wireless video services is soon to follow. However, bandwidth limited wireless channels coupled with mobility issues pose a great challenge in the hardware, ...
  • Dynamic Fault Reconfigurable Intelligent Control Architectures for Robotics 

    Cavallaro, Joseph R.; Walker, Ian D. (1993-04-01)
    In this paper we describe new progress in our development of an Intelligent Control Framework for robots which dynamically reconfigures itself to cope with faults in either sensors or joint hardware. The Framework is ...
  • A Dynamic Fault Tolerance Framework for Remote Robots 

    Visinsky, Monica L.; Cavallaro, Joseph R.; Walker, Ian D. (1995-08-01)
    Fault tolerance is increasingly important for robots, especially those in remote or hazardous environments. Robots need the ability to effectively detect and tolerate internal failures in order to continue performing their ...
  • Dynamic Senor-Based Fault Detection for Robots 

    Visinsky, Monica L.; Cavallaro, Joseph R.; Walker, Ian D. (1993-09-01)
    Fault detection and fault tolerance are increasingly important for robots in space or hazardous environments due to the dangerous and often inaccessible nature of these environs. We have previously developed algorithms to ...
  • Edge Localized Image Sharpening via Reassignment with Application to Computed Tomography 

    Dorney, Timothy D.; Bhashyam, Srikrishna; Doran, Andrew; Choi, Hyeokho; Flandrin, Patrick; Baraniuk, Richard G. (2000-07-01)
    Traditional filtering methods operate on the entire signal or image. In some applications, however, errors are concentrated in specific regions or features. A prime example is images generated using computed tomography. ...
  • The effect of LLR clipping to the complexity of list sphere detector algorithms 

    Myllylä, Markus; Antikainen, Juho; Juntti, Markku; Cavallaro, Joseph R. (2007-11-01)
    The optimal detection for coded system requires the use of a maximum a posteriori (MAP) detection. A list sphere detector (LSD) can be used to approximate the MAP detector. Depending on the used list size, LSD provides a ...
  • The Effect of Preprocessing to the Complexity of List Sphere Detector Algorithms 

    Myllylä, Markus; Juntti, Markku; Cavallaro, Joseph R. (2008-09-01)
    A list sphere detector (LSD) is an enhancement of a sphere detector (SD) that can be used to approximate the soft output MAP detector used in the detection of the multiple-input multiple-output (MIMO) signals. The LSD ...
  • An Efficient Circulant MIMO Equalizer for CDMA Downlink: Algorithm and VLSI Architecture 

    Guo, Yuanbin; Zhang, Jianzhong (Charlie); McCain, Dennis; Cavallaro, Joseph R. (2005-12-01)
    In this paper, we present an efficient circulant approximation based MIMO equalizer architecture for the CDMA downlink. This reduces the Direct-Matrix-Inverse (DMI) of size (NF x NF) with O((NF)³) complexity to some ...
  • An Efficient Circulant MIMO Equalizer for CDMA Downlink: Algorithm and VLSI Architecture 

    Guo, Yuanbin; Zhang, Jianzhong; McCain, Dennis; Cavallaro, Joseph R. (2006-02-01)
    We present an efficient circulant approximation-based MIMO equalizer architecture for the CDMA downlink. This reduces the direct matrix inverse (DMI) of size (NF×NF) with O((NF)3) complexity to some FFT operations with ...
  • An Efficient Detection Technique for Synchronous CDMA Communication Systems Based on the Expectation Maximization Algorithm 

    Borran, Mohammad Jaber; Nasiri-Kenari, Masoumeh (2000-09-20)
    Maximum likelihood detection of superimposed signals in code-division multiple access (CDMA) communication systems has a computational complexity that is exponential in the number of users, and its implementation is ...
  • Efficient hardware implementation of a highly-parallel 3GPP LTE/LTE-advance turbo decoder 

    Sun, Yang; Cavallaro, Joseph R. (2011-09-01)
    We present an efficient VLSI architecture for 3GPP LTE/LTE-Advance Turbo decoder by utilizing the algebraic-geometric properties of the quadratic permutation polynomial (QPP) interleaver. The high throughput 3GPP LTE/LTE-Advance ...