Results 1 - 10 of 108,694

A Study of Performance Enhancement Schemes for Multicarrier Transmission

by Chhavi Choudhary, Vishal Gupta
"... OFDM allow the transmission of high data rates over broadband channel due to the spectral bandwidth efficiency, robustness to the multipath delay etc. However OFDM signal are very sensitive to nonlinear effects due to the high peak-toaverage power radio (PAPR), which is one of the major drawback of ..."
Abstract - Cited by 1 (0 self) - Add to MetaCart
of OFDM system. The high PAPR results, high inband distortion and out-of- band radiation,inter-carrier interference(ICI) and degradation of bit error rate (BER) performance, all these losses occur due to the non-linearity of HPA(high power amplifier). The complexity of analog-todigital converter (ADC

A Scheme for Real-Time Channel Establishment in Wide-Area Networks

by Domenico Ferrari, Dinesh C. Verma - IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS , 1990
"... Multimedia communication involving digital audio and/or digital video has rather strict delay requirements. A real-time channel is defined in this paper as a simplex connection between a source and a destination characterized by parameters representing the performance requirements of the client. A r ..."
Abstract - Cited by 702 (31 self) - Add to MetaCart
Multimedia communication involving digital audio and/or digital video has rather strict delay requirements. A real-time channel is defined in this paper as a simplex connection between a source and a destination characterized by parameters representing the performance requirements of the client. A

Range-Free Localization Schemes for Large Scale Sensor Networks

by Tian He, Chengdu Huang, Brain M. Blum, John A. Stankovic, Tarek Abdelzaher , 2003
"... Wireless Sensor Networks have been proposed for a multitude of location-dependent applications. For such systems, the cost and limitations of hardware on sensing nodes prevent the use of range-based localization schemes that depend on absolute point-to-point distance estimates. Because coarse accura ..."
Abstract - Cited by 525 (8 self) - Add to MetaCart
performs best when an irregular radio pattern and random node placement are considered, and low communication overhead is desired. We compare our work via extensive simulation, with three state-of-the-art range-free localization schemes to identify the preferable system configurations of each. In addition

A Compositional Approach to Performance Modelling

by Jane Hillston , 1996
"... Performance modelling is concerned with the capture and analysis of the dynamic behaviour of computer and communication systems. The size and complexity of many modern systems result in large, complex models. A compositional approach decomposes the system into subsystems that are smaller and more ea ..."
Abstract - Cited by 757 (102 self) - Add to MetaCart
easily modelled. In this thesis a novel compositional approach to performance modelling is presented. This approach is based on a suitably enhanced process algebra, PEPA (Performance Evaluation Process Algebra). The compositional nature of the language provides benefits for model solution as well

Performance Analysis of the IEEE 802.11 Distributed Coordination Function

by Giuseppe Bianchi , 2000
"... Recently, the IEEE has standardized the 802.11 protocol for Wireless Local Area Networks. The primary medium access control (MAC) technique of 802.11 is called distributed coordination function (DCF). DCF is a carrier sense multiple access with collision avoidance (CSMA/CA) scheme with binary slott ..."
Abstract - Cited by 1869 (1 self) - Add to MetaCart
Recently, the IEEE has standardized the 802.11 protocol for Wireless Local Area Networks. The primary medium access control (MAC) technique of 802.11 is called distributed coordination function (DCF). DCF is a carrier sense multiple access with collision avoidance (CSMA/CA) scheme with binary

The sources and consequences of embeddedness for the economic performance of organizations: The network effect

by Brian Uzzi - American Sociological Review , 1996
"... In this paper, I attempt to advance the concept of embeddedness beyond the level of a programmatic statement by developing a formulation that specifies how embeddedness and network structure affect economic action. On the basis of existing theory and original ethnographies of 23 apparel firms, I dev ..."
Abstract - Cited by 744 (8 self) - Add to MetaCart
develop a systematic scheme that more fully demarcates the unique features, functions, and sources of embeddedness. From this scheme, I derive a set of refutable implications and test their plausibility, using another data set on the network ties of all better dress apparel firms in the New York apparel

A comparison of mechanisms for improving TCP performance over wireless links

by Hari Balakrishnan, Venkata N. Padmanabhan, Srinivasan Seshan, Randy H. Katz - IEEE/ACM TRANSACTIONS ON NETWORKING , 1997
"... Reliable transport protocols such as TCP are tuned to perform well in traditional networks where packet losses occur mostly because of congestion. However, networks with wireless and other lossy links also suffer from significant losses due to bit errors and handoffs. TCP responds to all losses by i ..."
Abstract - Cited by 927 (11 self) - Add to MetaCart
by invoking congestion control and avoidance algorithms, resulting in degraded end-to-end performance in wireless and lossy systems. In this paper, we compare several schemes designed to improve the performance of TCP in such networks. We classify these schemes into three broad categories: end

The Aurora Experimental Framework for the Performance Evaluation of Speech Recognition Systems under Noisy Conditions

by David Pearce, Hans-günter Hirsch, Ericsson Eurolab Deutschland Gmbh - in ISCA ITRW ASR2000 , 2000
"... This paper describes a database designed to evaluate the performance of speech recognition algorithms in noisy conditions. The database may either be used to measure frontend feature extraction algorithms, using a defined HMM recognition back-end, or complete recognition systems. The source speech f ..."
Abstract - Cited by 534 (6 self) - Add to MetaCart
This paper describes a database designed to evaluate the performance of speech recognition algorithms in noisy conditions. The database may either be used to measure frontend feature extraction algorithms, using a defined HMM recognition back-end, or complete recognition systems. The source speech

Sparse MRI: The Application of Compressed Sensing for Rapid MR Imaging

by Michael Lustig, David Donoho, John M. Pauly - MAGNETIC RESONANCE IN MEDICINE 58:1182–1195 , 2007
"... The sparsity which is implicit in MR images is exploited to significantly undersample k-space. Some MR images such as angiograms are already sparse in the pixel representation; other, more complicated images have a sparse representation in some transform domain–for example, in terms of spatial finit ..."
Abstract - Cited by 538 (11 self) - Add to MetaCart
undersampling schemes are developed and analyzed by means of their aliasing interference. Incoherence is introduced by pseudo-random variable-density undersampling of phase-encodes. The reconstruction is performed by minimizing the ℓ1 norm of a transformed image, subject to data fidelity constraints. Examples

Diversity and Multiplexing: A Fundamental Tradeoff in Multiple Antenna Channels

by Lizhong Zheng, David N. C. Tse - IEEE Trans. Inform. Theory , 2002
"... Multiple antennas can be used for increasing the amount of diversity or the number of degrees of freedom in wireless communication systems. In this paper, we propose the point of view that both types of gains can be simultaneously obtained for a given multiple antenna channel, but there is a fund ..."
Abstract - Cited by 1165 (20 self) - Add to MetaCart
fundamental tradeo# between how much of each any coding scheme can get. For the richly scattered Rayleigh fading channel, we give a simple characterization of the optimal tradeo# curve and use it to evaluate the performance of existing multiple antenna schemes.
Results 1 - 10 of 108,694