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33rd Annual IEEE Military Communications Conference on Affordable Mission Success - Meeting the Challenge (MILCOM)

作者： Irizarry, Alfredo Vega Fam, Adly Air Force Res Lab Rome NY 13441 USA SUNY Buffalo New York NY USA

ISBN: (纸本)9781479967704

A new algorithm for classifying direct sequence code division multiple access (DS-CDMA) signals in additive white Gaussian noise (AGWN) is proposed based on the average likelihood (AL) function. The AL is express in terms of the code length and the number of active users. These parameters constitute the hypothesis under test. While the AL function is expressed in an analytical form, the implementation requires knowledge on the spreading codes that acchive a low Total Squared Correlation (TSC) value. This complexity can be simplified by developing a hard decision scheme which only requires knowledge on matrices that achieve the lowest TSC. Our study cases include binary and multiclass classification using full loaded DS-CDMA with knowledge onf the chip period. code lengths of powers of 2 are used as a proof of concept.

关键词： AWGN code division multiple access codes matrix algebra signal classification spread spectrum communication AGWN AL function method DS-CDMA signal classification additive white Gaussian noise average likelihood function method binary classification chip period code length direct sequence code division multiple access signal classification hard decision scheme low total squared correlation value multiclass classification number-of-active users spreading codes Classification algorithms Complexity theory Correlation Error correction Error correction codes Multiaccess communication Vectors AWGN code division multiple access code length spreading code Multi access systems Error correction codes Sorting algorithm Spread spectrum communication signal classification Complexity theory direct-sequence code-division multiple access matrix algebra error correction

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JOINT PARALLEL INTERFERENCE CANCELLATION AND RELAY SELECTION ALGORITHMS BASED ON GREEDY TECHNIQUES FOR COOPERATIVE DS-CDMA SYSTEMS

JOINT PARALLEL INTERFERENCE CANCELLATION AND RELAY SELECTION...

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IEEE International Conference on Acoustics, Speech and Signal Processing

作者： Jiaqi Gu Rodrigo C. de Lamare Communications Research Group Department of Electronics University of York U.K.

ISBN: (纸本)9781479928941

In this work, we propose a cross-layer design strategy based on the parallel interference cancellation (PIC) detection technique and a multi-relay selection algorithm for the uplink of cooperative direct-sequence code-division multiple access (DS-CDMA) systems. We devise a low-cost greedy list-based PIC (GL-PIC) strategy with RAKE receivers as the front-end that can approach the maximum likelihood detector performance. We also present a low-complexity multi-relay selection algorithm based on greedy techniques that can approach the performance of an exhaustive search. Simulations show an excellent bit error rate performance of the proposed detection and relay selection algorithms as compared to existing techniques.

关键词： selection algorithm CDMA mobile communications direct-sequence code-division multiple access bit error rate performance RAKE receivers relay CANCELLATIONS up link Joints

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DS-CDMA Implementation With Iterative multiple access Interference Cancellation

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS 2013年第1期60卷 222-231页

作者： Dodd, Russell Schlegel, Christian Gaudet, Vincent Univ Alberta Edmonton AB T6G 2R3 Canada Univ Waterloo Dept Elect & Comp Engn Waterloo ON N2L 3G1 Canada

In this paper an implementation of iterative joint detection for multiple access interference using direct-sequence code-division multiple-access (DS-CDMA) is presented. Results for multiple field programmable gate array (FPGA) platforms and multiple technology nodes for synthesized application specific integrated circuits (ASIC) are presented. The joint detection is performed using a generalized version of interleave-division multiple-access (IDMA) known as partition spreading (PS) CDMA. Decoding is performed using iterative methods from turbo and sum-product decoding. The synthesized ASIC system demonstrates a maximum aggregate throughput of 197 Mb/s for a fully loaded 50-user system, while the implemented FPGA 50-user system has a maximum aggregate throughput of 119 Mb/s.

关键词： Digital circuits direct-sequence code-division multiple access field programmable gate arrays interference cancellation

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Dual-Antenna Based Blind Hostile Jamming Suppression and Multi-user Detection Scheme for DS-CDMA Systems with Unknown Hostile Jamming

Dual-Antenna Based Blind Hostile Jamming Suppression and Mul...

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International Conference on Information Science and Technology (ICIST)

作者： Zhang, Jiang Zhang, Hang PLA Univ Sci & Technol Coll Commun Engn Nanjing 210007 Jiangsu Peoples R China

ISBN: (纸本)9781467351379

The performance of direct-sequence code-division multiple access (DS-CDMA) systems may be significantly degraded if the system is severely jammed. In this paper, we propose a blind hostile jamming suppression and multi-user detection (MUD) scheme for the uplink of hostile jamming dominant DS-CDMA system. Based on using dual receive antennas, this scheme exploits the unknown spatial correlation of the jamming components between two antennas to eliminate the unknown hostile jamming and then performs MUD based independent component analysis (ICA). Simulation results demonstrate that the proposed scheme perform well in hostile jamming dominant scenario.

关键词： jamming dual antenna CDMA mobile communications mud direct-sequence code-division multiple access Multiuser detection up link sequence coding Dual

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On the Peak-to-Average Power Ratio Reduction Problem for Orthogonal Transmission Schemes

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INTERNET MATHEMATICS 2013年第2-3期9卷 265-296页

作者： Boche, Holger Farrell, Brendan Tech Univ Munich Inst Theoret Informat Technol Theresienstr 90 D-80333 Munich Germany CALTECH Comp & Math Sci Pasadena CA 91125 USA

High peak values of transmission signals in wireless communication systems lead to wasteful energy consumption and out-of-band radiation. However, reducing peak values generally comes at the cost of some other resource. We provide a theoretical contribution toward understanding the relationship between peak value reduction and the resulting cost in information rates. In particular, we address the relationship between peak values and the proportion of transmission signals allocated for information transmission when one is using a strategy known as tone reservation. We show that when tone reservation is used in both OFDM and DS-CDMA systems, if a peak-to-average power ratio criterion is always satisfied, then the proportion of transmission signals that may be allocated for information transmission must tend to zero. We investigate properties of these two systems for sets of both finite and infinite cardinalities. We present properties that OFDM and DS-CDMA share in common as well as ways in which they fundamentally differ.

关键词： Orthogonal frequency division multiplexing direct-sequence code-division multiple access data transmission PEAK VALUES Peak to average power ratio Proportion signals Information rates Wireless communication systems CDMA mobile communications

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New Blind Multiuser Detection DS-CDMA Algorithm Using Simplified Fourth Order Cumulant Matrices

New Blind Multiuser Detection DS-CDMA Algorithm Using Simpli...

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IEEE International Symposium on Circuits and Systems

作者： Zaid Albataineh Fathi Salem Circuits Systems And Neural Networks (CSANN) Laboratory Department of Electrical and Computer Engineering Michigan State University East Lansing Michigan 48824-1226 U.S.A.

ISBN: (纸本)9781467357609

A new blind Detection algorithm based on simplified fourth order cumulant matrices is presented and applied to the multi-user symbol estimation problem in direct sequence code division multiple access (DS-CDMA) systems. The blind detection is to estimate multiple symbol sequences associated with all users in the downlink of DS-CDMA communication system using only the received wireless data and without any knowledge of the user spreading codes. The proposed algorithm takes advantage of higher cumulant matrix properties to reduce computational load and enhance performance. Bit error rate (BER) simulations of this algorithm are shown for different number of users, signal to noise ratio (SNR) and different number of symbols per user in comparison with the FAST ICA algorithm and Robust ICA. The results show that the proposed algorithm outperforms the both ICA-Detectors in estimating the symbol signals from the mixed CDMA received signals.

关键词： DS-CDMA BER SNR direct-sequence code-division multiple access signal to noise ratios Bit error rate Supernova remnants Consumers Ziziphus mauritiana wireless data Blind Detection algorithms

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Peak Behavior and Information Rates for Orthonormal Systems

Peak Behavior and Information Rates for Orthonormal Systems

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IEEE Vehicular Technology Conference

作者： Holger Boche Brendan Farrell Lehrstuhl für Theoretische Information-stechnik Technische Universit?t München Arcisstr. 21 80333 MünchenGermany Computing and Mathematical Sciences California Institute of Technology 1200 E. California Blvd. Pasadena CA 91125 USA

ISBN: (纸本)9781467363365

High signal peak values are one of the fundamental obstacles to greater efficiency in wireless communications systems. There exist many techniques to reduce signal peak values;however, there have been few theoretical studies of the trade-off between reducing peak values and the resulting cost in other resources. Here we address the trade-off between peak reduction and information rates for two standard systems, OFDM and DS-CDMA, when implementing tone reservation. In particular, we show that when a peak threshold is strictly enforced regardless of the number of carriers, the information rate must tend to zero. We discuss aspects that these two systems share in common, as well as point out a fundamental way in which they differ.

关键词： fundamental reduction information Information rates Wireless communication systems signal peak Peak Reduction Theoretical Study direct-sequence code-division multiple access Orthogonal Commerce Strictly tradeoffs

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Path Loss Modelling for Location Service Applications

Path Loss Modelling for Location Service Applications

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European Conference on Antennas and Propagation

作者： Slawomir J. Ambroziak Ryszard J. Katulski Jaroslaw Sadowski Jacek Stefanski Department of Radio Communication Systems and Networks Faculty of Electronics Telecommunications and Informatics Gdansk University of Technology Gdansk Poland

ISBN: (纸本)9781467321877

The aim of this paper is the path loss modeling for the radiolocation services in radiocommunication networks, particularly in cellular networks. The main results of the measurements obtained in the physical layer of the UMTS are introduced. A new method for the utilization of the multipath propagation phenomenon to improve the estimation of the distance between the mobile station (MS) and the base station (BS) is outlined. This method significantly increases the quality of location services in systems which use a radio interface with direct sequence code division multiple access (DS CDMA).

关键词： path loss direct-sequence code-division multiple access radio interface measurement result Physical layer Modeling RADIO LOCATING

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MULTICARRIER CHIP PULSE SHAPE DESIGN WITH LOWPAPR

MULTICARRIER CHIP PULSE SHAPE DESIGN WITH LOWPAPR

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European Signal Processing Conference

作者： Mariano Vergara Felix Antreich Gonzalo Seco-Granados German Aerospace Center (DLR) Institute for Communications and Navigation 82234 Wessling Germany SPCOMNAV Department of Telecommunications and Systems Engineering Universitat Autónoma de Barcelona (UAB) 08193 Bellatera (Barcelona) Spain

ISBN: (纸本)9781479936878

In this paper we present a methodology to design pulse shapes for a direct sequence code division multiple access (DS-CDMA) ranging signal, using a multicarrier (MC) modulation. The advantage of this signal design methodology is that it allows us to perform spectral shaping with very low Peak-to-Average-Power Ratio (PAPR). This feature makes this approach very interesting for ranging systems for which flexible resource allocation and power efficiency are major concerns, e.g. GNSS (Global Navigation Satellite Systems).

关键词： Multicarrier ranging signal low PAPR chip pulse shape design direct-sequence code-division multiple access Pulse shape Resource utilization Peak to average power ratio dynamic efficiency Children's Health Insurance Program range measurement system Spectral shape Satellite navigation systems

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Simultaneous Round-Trip Time-of-Flight Measurements With Encoded Acoustic Signals

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IEEE SENSORS JOURNAL 2012年第10期12卷 2931-2940页

作者： De Marziani, Carlos Urena, Jesus Hernandez, Alvaro Jesus Garcia, Juan Alvarez, Fernando J. Jimenez, Ana Carmen Perez, Ma Villadangos Carrizo, Jose Manuel Aparicio, Joaquin Alcoleas, Romulo Consejo Nacl Invest Cient & Tecn Natl Council Sci & Tech Res RA-1033 Buenos Aires DF Argentina Univ Alcala Dept Elect Madrid 28871 Spain Univ Extremadura Fac Ciencias Dept Elect Engn Elect & Automat Badajoz 06006 Spain

In relative positioning systems, with the aim of estimating object positions, distances among them are computed in a cooperative way, usually by measuring times-of-flight from the signals that they emit. These emissions are often synchronized with additional signals or suitable hardware that acts as a temporal reference. In this paper, a ranging system is presented where only acoustic emissions are used to compute the distances between objects or nodes. Thus, an organization and operation algorithm is proposed, which provides a temporal reference to the acoustic emissions carried out by every node. In this way, distances are computed by determining the temporal relation between a request of emission from a coordinator node and the corresponding answers emitted by the other nodes. In order to simultaneously detect the acoustic emissions, the signals are encoded with complementary set of sequences allowing multisensory operation and accepting low signal-to-noise conditions. With this measurement scheme, additional signals and high accuracy clocks often used for synchronization can be eliminated, thus reducing hardware complexity, power consumptions, and possible interferences with other systems (i.e. if radio frequency signals are used). The simulation and experimental results show that sub-centimeter accuracy can be obtained with the proposed ranging scheme.

关键词： Acoustic signal processing distance measurement direct-sequence code-division multiple access relative localization sensor network

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