Research Letter Chip-Level HARQ Chase Combining for HSUPA
|
|
- Arron Darcy Booth
- 5 years ago
- Views:
Transcription
1 Research Letters in Counications Volue 29, Article ID 23276, 4 pages doi:11155/29/23276 Research Letter Chip-Level HARQ Chase Cobining for HSUPA Mohaed Et Tolba, 1, 2 Sair Saoudi, 1, 2 Raphaël Visoz, 3 and Tarik Ait-Idir 4 1 Lab-STICC, Institut Teleco, Teleco Bretagne, UMR CNRS 3192 Lab-STICC, Technopôle Brest-Iroise, CS Brest Cedex 3, France 2 TELECOM Bretagne institution, Universitéeuropéenne de Bretagne UEB), France 3 Orange Labs, 38-4 rue du generale-leclerc, Issy Moulineaux Cedex 9, France 4 Counication Systes Departent, Institut National des Postes et Télécounications INPT), Madinat Al Irfane, Rabat 1, Morocco Correspondence should be addressed to Mohaed Et Tolba, ohaedettolba@teleco-bretagneeu Received 19 Noveber 28; Accepted 23 January 29 Recoended by Adnan Kavak Hybrid autoatic repeat request HARQ) is used in high-speed uplink packet access HSUPA) to increase the data rate Chase cobining is the siplest of HARQ algoriths It provides a tie diversity and requires a sall eory In this paper, we propose a technique to increase the chase cobining efficiency In this ethod, HARQ transissions are seen as additional receive antennas which are jointly cobined at chip-level using a space-tie linear iniu square error LMMSE) We deonstrate that the chase cobining diversity gain is considerably increased especially for high-order odulation Copyright 29 Mohaed Et Tolba et al This is an open access article distributed under the Creative Coons Attribution License, which perits unrestricted use, distribution, and reproduction in any ediu, provided the original work is properly cited 1 Introduction High-speed uplink packet access HSUPA) is designed to reach high data rates in universal obile telecounications syste UMTS) uplink Its ipleentation includes new technologies such as fast scheduling as well as hybrid autoatic repeat request HARQ) There are two wellknown HARQ algoriths used for HSUPA: chase cobining and increental redundancy IR) [1] In chase cobining algorith, when a received packet is erroneous, it is saved in the receiver buffer and a negative acknowledgent NACK) is sent to the transitter in order to retransit the packet At the receiver end, the retransitted packet is cobined, before decoding, with the previously saved one [2] This results in a tie diversity gain for ultipath channels In the IR approach, each retransission carries additional redundancy, and a coding gain is provided after cobining different HARQ transissions The conventional rake receiver with receive diversity is used for detecting HARQ transission in HSUPA syste It has been deonstrated that this receiver provides good perforance for high spreading factors with binary phaseshift keying BPSK) odulation However, it exhibits a significant perforance degradation in the case of low spreading factors with high-order odulation The chiplevel LMMSE equalizer has been proposed for HSUPA as a solution to this perforance degradation It was subject to any studies in recent years In [3], authors have shown that the LMMSE chip-level equalizer with receive diversity provides a significant perforance enhanceent for high speed downlink packet access HSDPA) The chip LMMSE has been extended to MIMO ulticode CDMA syste in [4] without taking account of HARQ In [5], the LMMSE is jointly applied with HARQ at sybol-level for spacetie bit interleaved coded odulation STBICM) systes over ultiple input ultiple output MIMO) channel with intersybol interference ISI) Soft bit-level cobining is the siplest way to cobine HARQ transissions before decoding In addition to its ipleentation siplicity, it has been shown that this ethod offers a considerable gain for HSUPA [1] However, its perforance is severely degraded in fading channels when it is used with chase cobining for high-order odulation To overcoe this perforance degradation, we propose a chip-level cobining ethod based on LMMSE chip equalizer which is an interference resistant receiver In this
2 2 Research Letters in Counications ethod, HARQ transissions are seen as additional receive antennas Hence, the receive diversity gain is increased The different HARQ transissions receive antennas) are jointly exploited by a single LMMSE filter to provide the equalized chip as the cobining result In this anner, we jointly benefit fro the tie diversity provided by the ultipath channel, and the space diversity offered by the receive antennas It is shown that the proposed ethod outperfors the soft bit-level cobining A considerable gain is provided in the case of high-order odulation 2 HSUPA Syste Overview To reach the required quality of service, HSUPA introduces a new transport channel naed enhanced dedicated channel E-DCH) which supports sophisticated signal processing operations For error detection, it uses a cyclic redundancy check CRC) code which adds 24 bits to each HSUPA transport block The CRC code is followed by a 1/3 turbo code to protect E-DCH data against channel ipairent After channel coding, a rate atching operation is applied to adapt the nuber of bits at the output of turbo code to the desirable data rate One or several E-DCH dedicated physical data channels E-DPDCHs) are then used to carry the E- DCH data [6] The E-DPDCHs are separately interleaved and a bit to sybol apping is applied for each E-DPDCH In the case of BPSK odulation, each bit is apped to a sybol which takes value in { 1, +1} Recently, the 16- quadrature aplitude odulation QAM) is also specified for HSUPA Its constellation is built using two orthogonal 4-pulse aplitude odulation PAM) constellations In 4- PAM, a set of two consecutive bits, b k, k k+1 is converted to a real-valued sybol s k given by s k = 1 5 b k 2+bk+1 ) 1) After bit to sybol apping, each physical channel is spread with a real-valued orthogonal variable spreading factor OVSF) code The spreading factor ay be different fro one physical channel to another The spreading factor SF = 2 is allowed for HSUPA, especially for high data rates After the spreading, each physical channel is weighted by a gain factor in order to copensate the difference between spreading factors After that, the physical channels are IQ in-phase/quadratue-phase) ultiplexed to for a single coplex-valued strea of chips which is scrabled and sent through a ultipath channel A chip-spaced channel odel of length L is assued in this work The signal is received by two antennas at the receiver end A chip LMMSE equalizer of length 2E+1 is jointly applied to the two received signals for channel equalization After despreading, the signal is converted to the log-likelihood ratios LLR) required by the turbo decoder Before the decoding process, the LLR sequence is deinterleaved and inversely rate-atched The decoder is followed by a CRC decoder for residual error detectionwhenapacketisdetectedtobeinerror,itissaved and a NACK is sent to the transitter which retransits the packet At the receiver, the retransitted packet is y 1,1) y 2,1) y 1,Nt) y 2,Nt) LMMSE chip equalizer Despreading Figure 1: Chip-level cobining LLR coputation To turbo decoder cobined with the previously received one This increases the probability of correct decoding 3 Syste Model Consider an observation window of length 2E + 1, and let us denote by x the vector corresponding to the transitted ulticode chip at the instant T c, wheret c is the chip duration When the HARQ is not considered, the received signal at the base station is expressed as ) ) ) y 1 H 1 n 1 y 2 = H 2 x + n 2, 2) where y i = [y i E,, y i,, y i +E] T is the received signal at the ith i = 1, 2) antenna when the vector x = [x E L+1,, x,, x +E ] T is transitted through the ultipath channel represented by the 2E +1) 2E + L) Toeplitz atrix H i between the transit antenna and the ith receive antenna n i = [ni E,, n i,, n i +E] T is a vector of coplex white Gaussian noise saples each of which has the power spectral density N The received signals y 1 and y 2 are jointly delivered to a space-tie LMMSE chip equalizer to reduce the interference effect The equalizer output corresponding to the th chip is expressed as x = w H y, 3) where w is the space-tie LMMSE filter of size 22E +1), ) H denotes the Heritian operator, and y = [ y 1T y 1T is the concatenation of the received signals The space-tie LMMSE filter is expressed as w = HH H + N ) 1 I H E+L, 4) E c where H = [ H 1 H 2] T Its size is 22E +1) 2E + L) HE+L is the E + L)th colun of the atrix H, ande c is the total chip energy After chip equalization, the despreading process is perfored The resulting signal is then used to copute LLR values which are need by turbo decoding When HARQ soft bit-level cobining is considered, chip equalization, despreading, and LLR values coputation are perfored individually for each HARQ transission If a block is erroneous after turbo decoding, its corresponding LLRs are saved to be cobined with those of retransitted block [5] ] T
3 Research Letters in Counications 3 Table 1: MCSs configurations MCS Nuber of codes Min SF Coding rate Modulation Max bit rate kbps) BPSK QAM Chip-Level Cobining In the chip-level cobining approach, each HARQ transission is seen as two additional receive antennas The transissions are jointly exploited by the LMMSE chip equalizer as shown in Figure 1Lety p,q) denote the received vector of the th chip on the pth antenna at qth HARQ transission, and n p,q) denote the noise vector corresponding to the th chip on the pth antenna at qth HARQ transission The syste odel after jth transission is expressed as see [7]) Y j) = H j) x + n j), 5) where Y j) = [y 1,1) ) T,y 2,1) ) T,,y 1,j) ) T,y 2,j) ) T ], n j) = [n 1,1) ) T,n 2,1) ) T,,n 1,j) ) T,n 2,j) ) T ], and H j) is the channel atrix after jth transission It is written as follows: H 1,1) H 2,1) H j) =, 6) H 1,j) H 2,j) where H p,q) p = 1, 2; q = 1,, j) is a Toeplitz atrix of size 2E +1) 2E + L)givenby h p,q) L 1 h p,q) H p,q) = h p,q) L 1 h p,q), 7) h p,q) L 1 h p,q) h p,q) l l L 1) in 7) are the channel taps associated to the pth receive antenna of the qth HARQ transission The tie delay between two successive HARQ transissions, round-trip delay RTD), is taken into account in the propagation channel generation HARQ transissions are separately received in tie by two receive antennas At the receiver side, with the aid of a buffer and concatenation procedure expressed in 6), each HARQ transission can be viewed as a source of two ore virtual antennas In other words, the delay diversity will translate into space diversity which is exploited by a chip-level LMMSE equalizer The resulting chip after LMMSE filter is expressed by x j) = w j)) H Y j), 8) BLER Received E c /N per antenna db) Single trans Method12trans) Method22trans) Method 1 3 trans) Method 2 3 trans) Figure 2: Siulation results for MCS1 where w j) is written as ) 1 w j) = H j) H j)) H N + I H j) E c = A 1 H j) E+L, where H j) E+L is the E + L)th colun of the atrix H j) The coputation of the atrix inversion in 9) is done using the QR decoposition of the atrix A [8] Chip-level cobining ethod can be ipleented using a recursive technique This allows to get siilar coputationnal coplexity and a slightly increased eory requireent copared with soft bit-level cobining where HARQ transissions are separately equalized at the chip-level 5 Siulation and Results Coputer siulations are done for HSUPA syste The transitter is ipleented according to 3GPP technical specifications [9] The predefined odulation and coding schees MCSs) siulated in this work are shown in Table 1 For both MCSs two physical channels are spread with SF = 2, and the two others are spread with SF = 4 The transission is done over a ultipath channel which has a profile siilar to that of ITU-Pedestrian B which is considered to be block fading Because of the low obility of HSUPA obile, its speed is fixed at 3 K/h LMMSE chip filter of length 15 is applied for channel equalization Perfect channel knowledge is assued at the receiver SISO E+L 9)
4 4 Research Letters in Counications 1 References BLER Received E c /N per antenna db) Single trans Method 1 2 trans) Method 2 2 trans) Method 1 3 trans) Method 2 3 trans) Figure 3: Siulation results for MCS2 decoding is perfored using the Max-Log-MAP algorith with eight iterations In the following, we label the soft bitlevel cobining ethod, Method 1 The proposed cobining ethod is labeled Method 2 Siulations are done for chase cobining using Method 1 and Method 2 The two ethods are copared in ters of block error rate BLER) which is coputed as function of received E c /N per antenna Note that received E c /N is averaged over HARQ transissions Figure 2 shows the BLER results for MCS1 After two and three HARQ transissions, we observe that Method 2 outperfors Method 1 A gain of 3 db is provided after three transissions for BLER= 1 2 Figure 3 plots the BLER results, obtained with two and three HARQ transissions for MCS2 It is seen that Method 2 provides a significant gain over Method 1 for two and three HARQ transissions The proposed technique Method 2) offers an additional gain of 3 db at 1 2 with three HARQ transissions It is also observed that the perforance obtained by Method 1 after three transissions is reached by Method 2 with only two transissions This significant increase of chase cobining efficiency with Method 2 is due to the space diversity offered by the receive antennas, and the tie diversity provided by the chase algorith Moreover, the different transissions are jointly exploited by the LMMSE chip equalizer which is an interference-resistant detector [1] M Bertinelli and E Malkaäki, HARQ for WCDMA enhanced uplink: link level perforance in SHO, in Proceedings of the 15th IEEE International Syposiu on Personal, Indoor and Mobile Radio Counications PIMRC 4), vol 4, pp , Barcelona, Spain, Septeber 24 [2] D Chase, Code cobining a axiu-likelihood decoding approach for cobining an arbitrary nuber of noisy packets, IEEE Transactions on Counications, vol 33, no 5, pp , 1985 [3] J-B Landre and A Saadani, Receive diversity and LMMSE equalization benefits for HSDPA: realistic network throughputs, in Proceedings of the 18th IEEE International Syposiu on Personal, Indoor and Mobile Radio Counications PIMRC 7), pp 1 5, Athens, Greece, Septeber 27 [4] B-H Ki, X Zhang, and M Flury, Linear MMSE spacetie equalizer for MIMO ulticode CDMA systes, IEEE Transactions on Counications, vol 54, no 1, pp , 26 [5] T Ait-Idir, H Chafnaji, and S Saoudi, Joint hybrid ARQ and iterative space-tie equalization for coded transission over the MIMO-ISI channel, in Proceedings of the IEEE Wireless Counications and Networking Conference WCNC 8), pp , Las Vegas, Nev, USA, March-April 28 [6] 3GPP TS v75, Spreading and odulation FDD), Release 7, May 28 [7] ENOnggosanusi,AGDabak,YHui,andGJeong, Hybrid ARQ transission and cobining for MIMO systes, in Proceedings of the IEEE International Conference on Counications ICC 3), vol 5, pp , Anchorage, Alaska, USA, May 23 [8] W H Press, S A Teukolsky, W T Vetterling, and B P Flannery, Nuerical Recipes in C: The Art of Scientific Coputing, Cabridge University Press, Cabridge, UK, 1992 [9] 3GPP TS v78, Multiplexing and channel coding FDD), Release 7, May 28 6 Conclusion In this paper, we have proposed a new technique for HARQ chase cobining based on the LMMSE chip equalizer in HSUPA syste In this ethod, each transission is seen as two additional receive antennas at the input of the LMMSE filter The proposed ethod has been copared with the soft bit-level cobining for two and three transissions Siulation results have deonstrated a significant increase in chase cobining efficiency when using the proposed ethod especially for 16-QAM odulation
5 Rotating Machinery Volue 214 The Scientific World Journal Volue 214 Distributed Sensor Networks Sensors Volue Volue Volue 214 Control Science and Civil Volue 214 Volue 214 Subit your anuscripts at Electrical and Coputer Robotics Volue 214 Volue 214 VLSI Design OptoElectronics Navigation and Observation Volue Cheical Volue 214 Volue 214 Active and Passive Electronic Coponents Antennas and Propagation Aerospace Volue Volue 21 Volue 214 Modelling & Siulation in Volue Volue 214 Shock and Vibration Volue 214 Acoustics and Vibration Volue 214
Fast performance prediction of power controlled HSUPA with channel estimation
RESEARCH Open Access Fast performance prediction of power controlled HSUPA with channel estimation Mohamed Et-tolba 1*, Samir Saoudi 2 and Raphaël Visoz 3 Abstract Transmit power control (TPC) is used
More informationPerformance Analysis of an AMC System with an Iterative V-BLAST Decoding Algorithm
I. J. Counications, Network and Syste Sciences, 008,, 105-06 Published Online May 008 in SciRes (http://www.srpublishing.org/journal/ijcns/). Perforance Analysis of an AMC Syste with an Iterative V-BLAST
More informationKeywords Frequency-domain equalization, antenna diversity, multicode DS-CDMA, frequency-selective fading
Joint Frequency-doain Equalization and Antenna Diversity Cobining for Orthogonal Multicode DS-CDMA Signal Transissions in A Frequency-selective Fading Channel Taeshi ITAGAKI *1 and Fuiyui ADACHI *2 Dept.
More informationA soft decision decoding of product BCH and Reed-Müller codes for error control and peak-factor reduction in OFDM
A soft decision decoding of product BCH and Reed-Müller codes for error control and pea-factor reduction in OFDM Yves LOUET *, Annic LE GLAUNEC ** and Pierre LERAY ** * PhD Student and ** Professors, Departent
More informationResearch Letter Throughput of Type II HARQ-OFDM/TDM Using MMSE-FDE in a Multipath Channel
Research Letters in Communications Volume 2009, Article ID 695620, 4 pages doi:0.55/2009/695620 Research Letter Throughput of Type II HARQ-OFDM/TDM Using MMSE-FDE in a Multipath Channel Haris Gacanin and
More informationRAKE Receiver. Tommi Heikkilä S Postgraduate Course in Radio Communications, Autumn II.
S-72333 Postgraduate Course in Radio Counications, Autun 2004 1 RAKE Receiver Toi Heikkilä toiheikkila@teliasoneraco Abstract RAKE receiver is used in CDMA-based (Code Division Multiple Access) systes
More informationA Novel Link Error Prediction Model for OFDM Systems with HARQ
A Novel Link Error Prediction Model for OFDM Systes with HARQ Josep Colo Ikuno, Christian Mehlführer, Markus Rupp Institute of Counications and Radio-Frequency Engineering Vienna University of Technology,
More informationIterative Receiver Signal Processing for Joint Mitigation of Transmitter and Receiver Phase Noise in OFDM-Based Cognitive Radio Link
Iterative Receiver Signal Processing for Joint Mitigation of Transitter and Receiver Phase Noise in OFDM-Based Cognitive Radio Link Ville Syrjälä and Mikko Valkaa Departent of Counications Engineering
More informationCOMBINED FREQUENCY AND SPATIAL DOMAINS POWER DISTRIBUTION FOR MIMO-OFDM TRANSMISSION
The 8th nnual IEEE International Syposiu on Personal, Indoor and Mobile Radio Counications (PIMRC 07) COMINED FREQUENCY ND SPTIL DOMINS POWER DISTRIUTION FOR MIMO-OFDM TRNSMISSION Wladiir ocquet, Kazunori
More informationDIRECT MAPPING OVSF-BASED TRANSMISSION SCHEME FOR UNDERWATER ACOUSTIC MULTIMEDIA COMMUNICATION
Journal of Marine Science and Technology, Vol. 18, No. 3, pp. 413-418 (2010) 413 DIRECT MAPPING OVSF-BASED TRANSMISSION SCHEME FOR UNDERWATER ACOUSTIC MULTIMEDIA COMMUNICATION Chin-Feng Lin*, Jiang-Yao
More informationTransmit Power and Bit Allocations for OFDM Systems in a Fading Channel
Transit Power and Bit Allocations for OFD Systes in a Fading Channel Jiho Jang *, Kwang Bok Lee, and Yong-Hwan Lee * Sasung Electronics Co. Ltd., Suwon P.O.Box, Suwon-si, Gyeonggi-do 44-74, Korea School
More informationSECURITY AND BER PERFORMANCE TRADE-OFF IN WIRELESS COMMUNICATION SYSTEMS APPLICATIONS
Latin Aerican Applied Research 39:187-192 (2009) SECURITY AND BER PERFORMANCE TRADE-OFF IN WIRELESS COMMUNICATION SYSTEMS APPLICATIONS L. ARNONE, C. GONZÁLEZ, C. GAYOSO, J. CASTIÑEIRA MOREIRA and M. LIBERATORI
More information4G Communication Resource Analysis with Adaptive Physical Layer Technique
International Journal of Engineering Trends and Technology (IJETT) Volue 33 uber - March 206 4G Counication Resource Analysis with Adaptive Physical Layer Technique Mubinul Haque, Dr. Md. Abu Bakar Siddiqui
More informationMulticarrier Interleave-Division Multiple Access Communication in Multipath Channels
Multicarrier Interleave-Division Multiple Access Counication in Multipath Channels Habib ur Rehan *, Muhaad Naee **, Iran Zaa *, Syed Isail Shah ** * Center for Advanced Studies in Engineering (CASE) Islaabad
More informationResearch Article Dynamic Beamforming for Three-Dimensional MIMO Technique in LTE-Advanced Networks
Antennas and Propagation Volue 213, Article ID 76457, 8 pages http://dx.doi.org/1.1155/213/76457 Research Article Dynaic Beaforing for Three-Diensional MIMO Technique in LTE-Advanced Networks Yan Li, Xiaodong
More informationA Novel TDS-FDMA Scheme for Multi-User Uplink Scenarios
A Novel TDS-FDMA Schee for Multi-User Uplink Scenarios Linglong Dai, Zhaocheng Wang, Jun Wang, and Zhixing Yang Tsinghua National Laboratory for Inforation Science and Technology, Electronics Engineering
More informationAn orthogonal multi-beam based MIMO scheme. for multi-user wireless systems
An orthogonal ulti-bea based IO schee for ulti-user wireless systes Dong-chan Oh o and Yong-Hwan Lee School of Electrical Engineering and IC, Seoul ational University Kwana P.O. Box 34, Seoul, 151-600,
More informationUsing Adaptive Modulation in a LEO Satellite Communication System
Proceedings of the 11th WSEAS International Conference on COMMUNICATIONS, Agios Nikolaos, Crete Island, Greece, July 26-28, 27 255 Using Adaptive Modulation in a LEO Satellite Counication Syste L. HADJ
More informationMultiresolution MBMS Transmissions for MIMO UTRA LTE Systems
Multiresolution MBMS Transissions for MIMO UTRA LTE Systes Nuno Souto Aérico Correia Rui Dinis João Carlos Silva Luís Abreu ISCTE / Instituto de Telecounicações/ADETTI Lisboa Portugal nuno.souto@lx.it.pt
More informationHSPA & HSPA+ Introduction
HSPA & HSPA+ Introduction www.huawei.com Objectives Upon completion of this course, you will be able to: Understand the basic principle and features of HSPA and HSPA+ Page1 Contents 1. HSPA & HSPA+ Overview
More informationInternational Journal of Electronics and Electrical Engineering Vol. 1, No. 3, September, 2013 MC-DS-CDMA
International Journal of Electronics and Electrical Engineering Vol. 1, No. 3, Septeber, 2013 Analysis of Carrier Frequency Selective Offset Estiation - Using Zero-IF and ZCZ In MC-DS-CDMA Venkatachala.
More informationReceiver Design for Downlink MIMO MC-CDMA in Cognitive Radio Systems
1st Annual IEEE International Syposiu on Personal, Indoor and Mobile Radio Counications Receiver Design for Downlink MIMO MC-CDMA in Cognitive Radio Systes M. Raabzadeh 1, and. hoshbin 1 1 Electrical Engineering
More informationJoint Transmitter-Receiver Beamforming in Downlink Cyclic Prefix-free Spatio-Temporal MC-CDMA
Joint Transitter-Receiver Beaforing in Downlink Cyclic Prefix-free Spatio-Teporal MC-CDMA Ho Huat Peh, Athanassios Manikas, Tjeng Thiang Tjhung and Wai-Choong Wong Institute for Infoco Research, A*STAR,
More informationAdaptive Harmonic IIR Notch Filter with Varying Notch Bandwidth and Convergence Factor
Journal of Counication and Coputer (4 484-49 doi:.765/548-779/4.6. D DAVID PUBLISHING Adaptive Haronic IIR Notch Filter with Varying Notch Bandwidth and Convergence Factor Li Tan, Jean Jiang, and Liango
More informationA Comparison of Convolutional and Turbo Coding Schemes For Broadband FWA Systems
A Coparison of Convolutional and Turbo Coding Schees For Broadband FWA Systes Ioannis A. Chatzigeorgiou, Miguel R.. Rodrigues, Ian J. Wassell and Rolando Carrasco Abstract The block fading characteristics
More informationPerformance of Multiuser MIMO System Employing Block Diagonalization with Antenna Selection at Mobile Stations
Perforance of Multiuser MIMO Syste Eploying Bloc Diagonalization with Antenna Selection at Mobile Stations Feng Wang, Mare E. Bialowsi School of Inforation Technology and Electrical Engineering The University
More informationLETTER Adaptive Multi-Stage Parallel Interference Cancellation Receiver for Multi-Rate DS-CDMA System
IEICE TRANS. COMMUN., VOL.E87 B, NO.8 AUGUST 2004 2401 LETTER Adaptive Multi-Stage Parallel Interference Cancellation Receiver for Multi-Rate DS-CDMA Syste Seung Hee HAN a), Student Meber and Jae Hong
More informationEnhanced Algorithm for MIESM
Recent Patents on Signal Processing, 9,, -7 Enhanced Algorith for MIESM R. Sandanalakshi *, Shahid Mutaz * and Kazi Saidul * Open Access University of Aveiro, Aveiro, Portugal Abstract: The link adaptation
More informationThe PAPR and Simple PAPR Reduction of the 2D Spreading Based Communication Systems
RADIOENGINEERING, VOL. 9, NO., APRIL 7 The PAPR and Siple PAPR Reduction of the D Spreading Based Counication Systes Jiří BLUMENSTEIN, Zbyněk FEDRA Dept. of Radio Electronics, Brno University of Technology,
More information5 Constellation for Digital Modulation Schemes
5 Constellation for Digital Modulation Schees 5.1 PAM Definition 5.1. Recall, fro 3.6, that PAM signal wavefors are represented as s (t) = A p(t), 1 M where p(t) is a pulse and A A. 5.2. Clearly, PAM signals
More informationOverlapped frequency-time division multiplexing
April 29, 16(2): 8 13 www.sciencedirect.co/science/journal/158885 he Journal of China Universities of Posts and elecounications www.buptjournal.cn/xben Overlapped frequency-tie division ultiplexing JIANG
More informationImplementation of Adaptive Viterbi Decoder
Ipleentation of Adaptive Viterbi Decoder Devendra Made #1 VIII Se B.E.(Etrx) K.D.K.College of Engineering, Nagpur, Maharashtra(I) Asst. Prof. R.B. Khule *2 M.Tech V.L.S.I. K.D.K.College of Engineering,
More informationDefinition Recall, from 6.7, that PAM signal waveforms are represented
6.4 Constellations for Digital Modulation Schees 6.4.1 PAM Definition 6.45. Recall, fro 6.7, that PAM signal wavefors are represented as s (t) = A p(t), 1 M where p(t) is a pulse and A A. 6.46. Clearly,
More informationME-SSA: an Advanced Random Access for the Satellite Return Channel
IEEE ICC 5 SAC - Satellite and Space Counications ME-SSA: an Advanced Rando Access for the Satellite Return Channel G. Gallinaro, N. Alagha, R. De Gaudenzi, K. Kansanen, R. Müller, P. Salvo Rossi Abstract
More informationDSI3 Sensor to Master Current Threshold Adaptation for Pattern Recognition
International Journal of Signal Processing Systes Vol., No. Deceber 03 DSI3 Sensor to Master Current Threshold Adaptation for Pattern Recognition David Levy Infineon Austria AG, Autootive Power Train Systes,
More informationPerformance of Antenna Variable Modulation for Turbo MIMO Transmission in Frequency-Selective Channels *
Proceedings IG Worshop on Sart Antennas, Munich, Gerany, 18th-19th of March 4 Perforance of Antenna Variable Modulation for urbo MIMO ransission in Frequency-Selective Channels * Christian Schneider, Marcus
More informationSpace-Frequency Block Code for MIMO-OFDM Communication Systems with Reconfigurable. antennas.
Space-Frequency Block Code for MIMO-OFDM Counication Systes with Reconfigurable Antennas arxiv:15080334v1 csit 13 Aug 2015 Vida Vakilian Jean-François Frigon and Sébastien Roy École Polytechnique de Montréal
More informationORTHOGONAL frequency division multiplexing (OFDM) has become the most popular multicarrier
IEEE SIGNAL PROCESSING LETTERS 1 MultipleInput MultipleOutput OFDM with Index Modulation Ertuğrul Başar, Meber, IEEE Abstract arxiv:1510.06141v1 [cs.it] 1 Oct 015 Orthogonal frequency division ultiplexing
More informationKalman Filtering for NLOS Mitigation and Target Tracking in Indoor Wireless Environment
16 Kalan Filtering for NLOS Mitigation and Target Tracking in Indoor Wireless Environent Chin-Der Wann National Sun Yat-Sen University Taiwan 1. Introduction Kalan filter and its nonlinear extension, extended
More informationModeling Beam forming in Circular Antenna Array with Directional Emitters
International Journal of Research in Engineering and Science (IJRES) ISSN (Online): 2320-9364, ISSN (Print): 2320-9356 Volue 5 Issue 3 ǁ Mar. 2017 ǁ PP.01-05 Modeling Bea foring in Circular Antenna Array
More informationModel Development for the Wideband Vehicle-to-vehicle 2.4 GHz Channel
Model Developent for the Wideband Vehicle-to-vehicle.4 GHz Channel Guillero Acosta and Mary Ann Ingra School of ECE, Georgia Institute of Technology, Atlanta, GA 333-5, USA gte437k@ail.gatech.edu, ai@ece.gatech.edu
More informationAn Alamouti-based Hybrid-ARQ Scheme for MIMO Systems
An Alamouti-based Hybrid-ARQ Scheme MIMO Systems Kodzovi Acolatse Center Communication and Signal Processing Research Department, New Jersey Institute of Technology University Heights, Newark, NJ 07102
More informationAnalysis and Comparison of Time Replica and Time Linear Interpolation for Pilot Aided Channel Estimation in OFDM Systems
Int J Counications Networ and Syste Sciences 010 3 446-45 doi:10436/ijcns01035059 Published Online May 010 (http://wwwsciporg/journal/ijcns/) Analysis and Coparison of Tie eplica and Tie inear Interpolation
More informationPhase Noise Modelling and Mitigation Techniques in OFDM Communications Systems
Phase Noise Modelling and Mitigation Techniques in OFDM Counications Systes Ville Syrjälä, Mikko Valkaa, Nikolay N. Tchaov, and Jukka Rinne Tapere University of Technology Departent of Counications Engineering
More informationStudy and Implementation of Complementary Golay Sequences for PAR reduction in OFDM signals
Study and Ipleentation of Copleentary Golay Sequences for PAR reduction in OFDM signals Abstract In this paper soe results of PAR reduction in OFDM signals and error correction capabilities by using Copleentary
More informationSYSTEM LEVEL DESIGN CONSIDERATIONS FOR HSUPA USER EQUIPMENT
SYSTEM LEVEL DESIGN CONSIDERATIONS FOR HSUPA USER EQUIPMENT Moritz Harteneck UbiNetics Test Solutions An Aeroflex Company Cambridge Technology Center, Royston, Herts, SG8 6DP, United Kingdom email: moritz.harteneck@aeroflex.com
More informationA Frequency Domain Approach to Design Constrained Amplitude Spreading Sequences for DS-CDMA Systems for Frequency Selective Fading Channels
A Frequency Doain Approach to Design Constrained Aplitude Spreading Sequences for DS-CDMA Systes for Frequency Selective Fading Channels B.J.Peiris, K.R.Narayanan and S.L. Miller Dept. of Electrical Engineering
More informationOn the Golden Code Performance for MIMO-HSDPA System
On the Golden Code Performance for MIMO-HSDPA System Rim Ouertani, Ahmed Saadani, Ghaya Rekaya-Ben Othman and Jean-Claude Belfiore France Télécom Division R&D, 38-40 rue du General Leclerc, 9794 Issy Moulineaux,
More informationTransmit Beamforming and Iterative Water-Filling Based on SLNR for OFDMA Systems
Transit Beaforing and Iterative Water-Filling Based on SLNR for OFDMA Systes Kazunori Hayashi, Megui Kaneko, Takeshi Fui, Hideaki Sakai Graduate School of Inforatics, Kyoto University, Yoshida Honachi
More informationOutage Probability of Alamouti based Cooperative Communications with Multiple Relay Nodes using Network Coding
Outage Probability of Alaouti based Cooperative Counications with Multiple Relay Nodes using Network Coding Gordhan Das Menghwar and Christoph F. Mecklenbräuker 2 Inforation Technology Centre Sindh Agriculture
More informationEFFECTS OF MASKING ANGLE AND MULTIPATH ON GALILEO PERFORMANCES IN DIFFERENT ENVIRONMENTS
1 EFFECTS OF MASKING ANGLE AND MULTIPATH ON GALILEO PERFORMANCES IN DIFFERENT ENVIRONMENTS M. Malicorne*, M. Bousquet**, V. Calettes*** SUPAERO, 1 avenue Edouard Belin BP 43, 3155 Toulouse Cedex, France.
More informationMOBILE OPTICAL WIRELESS SYSTEM FOR HEALTHCARE CONTINUOUS MONITORING USING IR TECHNOLOGY
31 st August 015. Vol.78. No.3 005-015 JATIT & LLS. All rights reserved. ISSN: 199-8645 www.jatit.org E-ISSN: 1817-3195 MOBILE OPTICAL WIRELESS SYSTEM FOR HEALTHCARE CONTINUOUS MONITORING USING IR TECHNOLOGY
More informationADVANCED WIRELESS TECHNOLOGIES. Aditya K. Jagannatham Indian Institute of Technology Kanpur
ADVANCED WIRELESS TECHNOLOGIES Aditya K. Jagannatham Indian Institute of Technology Kanpur Wireless Signal Fast Fading The wireless signal can reach the receiver via direct and scattered paths. As a result,
More informationCooperative Hybrid-ARQ Protocols: Unified Frameworks for Protocol Analysis
Cooperative Hybrid-ARQ Protocols: Unified Fraeworks for Protocol Analysis Ilu Byun and Kwang Soon Ki Cooperative hybrid-autoatic repeat request (HARQ) protocols, which can exploit the spatial and teporal
More informationA New Filter-Bank Multicarrier System: The Linearly Processed FBMC System
1 A New Filter-Bank ulticarrier Syste: The Linearly Processed FBC Syste Jintae Ki, Student eber, IEEE, Yosub Park, eber, IEEE, Sungwoo Weon, Jinkyo Jeong, Student eber, IEEE, Sooyong Choi, eber, IEEE,
More informationVHDL-AMS Behavioral Modeling and Simulation of M-QAM transceiver system
SETT 7 th nternational Conference: Sciences Of Electronic, Technologies Of nforation And Telecounications March 5-9, 7 TUNSA VHDL-AMS Behavioral Modeling and Siulation of M-AM transceiver syste Kari JABER,
More informationLecture 12: Summary Advanced Digital Communications (EQ2410) 1
: Advanced Digital Communications (EQ2410) 1 Monday, Mar. 7, 2016 15:00-17:00, B23 1 Textbook: U. Madhow, Fundamentals of Digital Communications, 2008 1 / 15 Overview 1 2 3 4 2 / 15 Equalization Maximum
More informationNotes on Orthogonal Frequency Division Multiplexing (OFDM)
Notes on Orthogonal Frequency Division Multiplexing (OFDM). Discrete Fourier ransfor As a reinder, the analytic fors of Fourier and inverse Fourier transfors are X f x t t, f dt x t exp j2 ft dt (.) where
More informationADAPTIVE MMSE TURBO EQUALIZATION USING HIGH ORDER MODULATION: EXPERIMENTAL RESULTS ON UNDERWATER ACOUSTIC CHANNEL
ADAPTIVE MMSE TURBO EQUALIZATION USING HIGH ORDER MODULATION: EXPERIMENTAL RESULTS ON UNDERWATER ACOUSTIC CHANNEL C. Laot a, A. Bourré b and N. Beuzelin b a Institut Telecom; Telecom Bretagne; UMR CNRS
More informationResearch Article Time Reversal UWB Communication System: A Novel Modulation Scheme with Experimental Validation
Hindawi Publishing Corporation EURASIP Journal on Wireless Counications and Networking Volue 2010, Article ID 398401, 12 pages doi:10.1155/2010/398401 Research Article Tie Reversal UWB Counication Syste:
More informationAdaptive Co-Channel Interference Suppression Technique for Multi-User MIMO MC DS/CDMA Systems
Int. J. Counications, Networ an Syste Sciences, 009,, 8-86 oi:0.436/ijcns.009.9095 Publishe Online Deceber 009 (http://www.scirp.org/journal/ijcns/). Aaptive Co-Channel Interference Suppression Technique
More informationOverlapping Signal Separation in DPX Spectrum Based on EM Algorithm. Chuandang Liu 1, a, Luxi Lu 1, b
nd International Worshop on Materials Engineering and Coputer Sciences (IWMECS 015) Overlapping Signal Separation in DPX Spectru Based on EM Algorith Chuandang Liu 1, a, Luxi Lu 1, b 1 National Key Laboratory
More informationKeysight Technologies Concepts of High Speed Downlink Packet Access: Bringing Increased Throughput and Efficiency to W-CDMA
Keysight Technologies Concepts of High Speed Downlink Packet Access: Bringing Increased Throughput and Efficiency to W-CDMA Application Note Sub-frame # 1 2 3 4 5 6 7 8 9 10 11 12 13 HS-SCCH Control Control
More informationLinear Precoding Gain for Large MIMO Configurations with QAM and Reduced Complexity
Linear Precoding Gain for Large MIMO Configurations with QAM and Reduced Coplexity Thoas Ketseoglou, Senior Meber, IEEE, and Ender Ayanoglu, Fellow, IEEE Abstract In this paper, the proble of designing
More informationIntroduction Traditionally, studying outage or cellular systes has been based on the signal-to-intererence ratio (SIR) dropping below a required thres
Miniu Duration Outages in Rayleigh Fading Channels Jie Lai and Narayan B. Mandaya WINLAB, Rutgers University 73 Brett Rd., Piscataway, NJ 8854-86 Eail: jlai@winlab.rutgers.edu, narayan@winlab.rutgers.edu
More informationMODULATION AND CODING TECHNIQUES IN WIRELESS COMMUNICATIONS
MODULATION AND CODING TECHNIQUES IN WIRELESS COMMUNICATIONS Edited by Evgenii Krouk Dean of the Information Systems and Data Protection Faculty, St Petersburg State University of Aerospace Instrumentation,
More informationPrecise Indoor Localization System For a Mobile Robot Using Auto Calibration Algorithm
Precise Indoor Localization Syste For a Mobile Robot Using Auto Calibration Algorith Sung-Bu Ki, JangMyung Lee, and I.O. Lee : Pusan National University, http://robotics.ee.pusan.ac.r, : Ninety syste Abstract:
More informationThe Case for Optimum Detection Algorithms in MIMO Wireless Systems. Helmut Bölcskei
The Case for Optimum Detection Algorithms in MIMO Wireless Systems Helmut Bölcskei joint work with A. Burg, C. Studer, and M. Borgmann ETH Zurich Data rates in wireless double every 18 months throughput
More informationINTERFERENCE avoidance has emerged in the literature
1466 IEEE TANSACTIONS ON COMMUNICATIONS, VOL. 55, NO. 8, AUGUST 2007 Interference Avoidance and Multiaccess Vector Channels Diitrie C. Popescu, Senior Meber, IEEE, Otilia Popescu, Meber, IEEE, and Christopher
More informationThroughput Analysis for a UMTS High Speed Downlink Packet Access LMMSE Equalizer
Throughput Analysis for a UMTS High Speed Downlink Packet Access LMMSE Equalizer K. Freudenthaler, F. Kaltenberger 2, S. Geirhofer 3, S. Paul 4, J. Berkmann 4, J. Wehinger 5, C.F. Mecklenbräuker 5, A.
More informationOn the Reverse Link Capacity of cdma2000 High Rate Packet Data Systems
On the Reverse Link Capacity of cda High Rate Packet Data Systes Eduardo Esteves QUALCOMM Incorporated 5775 Morehouse Drive San Diego, CA 911-1714 Abstract cda high rate packet data standard, also known
More informationEvaluation of Percentage Capacity Loss on LTE Network Caused by Intermodulation Distortion in a Coexistence Scenario
International Journal of Science and Engineering Investigations vol. 6, issue 62, March 2017 ISSN: 2251-8843 Evaluation of ercentage Capacity Loss on LTE Network Caused by Interodulation Distortion in
More informationBlock Processing Linear Equalizer for MIMO CDMA Downlinks in STTD Mode
Block Processing Linear Equalizer for MIMO CDMA Downlinks in STTD Mode Yan Li Yingxue Li Abstract In this study, an enhanced chip-level linear equalizer is proposed for multiple-input multiple-out (MIMO)
More informationPower Optimal Signaling for Fading Multi-access Channel in Presence of Coding Gap
Power Optial Signaling for Fading Multi-access Channel in Presence of Coding Gap Ankit Sethi, Prasanna Chaporkar, and Abhay Karandikar Abstract In a ulti-access fading channel, dynaic allocation of bandwidth,
More informationBER Performance of CRC Coded LTE System for Various Modulation Schemes and Channel Conditions
Scientific Research Journal (SCIRJ), Volume II, Issue V, May 2014 6 BER Performance of CRC Coded LTE System for Various Schemes and Conditions Md. Ashraful Islam ras5615@gmail.com Dipankar Das dipankar_ru@yahoo.com
More informationwireless systems François Horlin, Frederik Petré, Eduardo Lopez-Estraviz, and Frederik Naessens
antennas for 4G wireless systes François Horlin, Frederik Petré, 33Multiple Eduardo Lopez-Estraviz, and Frederik Naessens It is not the strongest species that will survive, nor the ost intelligent, but
More informationEnergy Efficient Space Time Line Coded Regenerative Two-Way Relay Under Per-Antenna Power Constraints
SPECIAL SECTION ON GREEN SIGNAL PROCESSING FOR WIRELESS COMMUNICATIONS AND NETWORKING Received July 29, 2018, accepted August 20, 2018, date of publication August 23, 2018, date of current version Septeber
More informationNew Adaptive Linear Combination Structure for Tracking/Estimating Phasor and Frequency of Power System
28 Journal of Electrical Engineering & echnology Vol. 5, No., pp. 28~35, 2 New Adaptive Linear Cobination Structure for racking/estiating Phasor and Frequency of Power Syste Choowong-Wattanasakpubal and
More informationPREDICTING SOUND LEVELS BEHIND BUILDINGS - HOW MANY REFLECTIONS SHOULD I USE? Apex Acoustics Ltd, Gateshead, UK
PREDICTING SOUND LEVELS BEHIND BUILDINGS - HOW MANY REFLECTIONS SHOULD I USE? W Wei A Cooke J Havie-Clark Apex Acoustics Ltd, Gateshead, UK Apex Acoustics Ltd, Gateshead, UK Apex Acoustics Ltd, Gateshead,
More informationContent. WCDMA BASICS HSDPA In general HSUPA
HSPA essentials Content WCDMA BASICS HSDPA In general HSUPA WCDMA Network Architecture USIM card Affected elements for HSPA GSM/WCDMA mobile Uu GSM/WCDMA mobile WCDMA mobile Uu Uu BTS BTS RAN Iub Iub RNC
More informationWe are IntechOpen, the world s leading publisher of Open Access books Built by scientists, for scientists. International authors and editors
We are IntechOpen, the world s leading publisher of Open Access books Built by scientists, for scientists 3,900 116,000 10M Open access books available International authors and editors Downloads Our authors
More informationReceive Antenna Subset Selection For Time-Varying Channels Using Slepian Subspace Projections
Globeco - Wireless Counications Syposiu Receive Antenna Subset Selection For Tie-Varying Channels Using Slepian Subspace Projections Hassan A Abou Saleh and Steven D Blostein Departent of Electrical and
More informationBeacon-driven Leader Based Protocol over a GE Channel for MAC Layer Multicast Error Control
I. J. Counications, Network and Syste Sciences, 2008, 2, 05-206 Published Online May 2008 in Scies (http://www.spublishing.org/journal/ijcns/. Beacon-driven Leader Based Protocol over a GE Channel for
More informationUplink DPCCH Gating of Inactive UEs in Continuous Packet Connectivity Mode for HSUPA
Uplink DPCCH Gating of Inactive UEs in Continuous Packet Connectivity Mode for HSUPA Tao Chen 1, Esa Malkamäki, Tapani Ristaniemi 3 1 Nokia Technology Platforms, Nokia Research Center, 3 University of
More informationImplementation of Wideband Digital Beam Forming in the E-band
Ipleentation of Wideband Digital Bea Foring in the E-band Val Dyadyuk, Xiaojing Huang, Leigh Stokes, Joseph Pathikulangara ICT Centre, CSIRO, PO Box 76, Epping, NSW, Sydney, Australia This paper reports
More informationTechnology Introduction. White Paper
HSPA+ Technology Introduction Meik Kottkamp 0.202-MA-205_2E HSPA+ Technology Introduction White Paper High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA) optimize UMTS
More informationThe BER Evaluation of UMTS under Static Propagation Conditions
Proceedings of the 5th WSEAS Int. Conf. on System Science and Simulation in Engineering, Tenerife, Canary Islands, Spain, December 16-18, 2006 310 The BER Evaluation of UMTS under Static Propagation Conditions
More informationWireless Networks: An Introduction
Wireless Networks: An Introduction Master Universitario en Ingeniería de Telecomunicación I. Santamaría Universidad de Cantabria Contents Introduction Cellular Networks WLAN WPAN Conclusions Wireless Networks:
More informationA Novel Hybrid ARQ Scheme Using Packet Coding
27-28 January 26, Sophia Antipolis France A Novel Hybrid ARQ Scheme Using Pacet Coding LiGuang Li (ZTE Corperation), Jun Xu (ZTE Corperation), Can Duan (ZTE Corperation), Jin Xu (ZTE Corperation), Xiaomei
More informationFORWARD MASKING THRESHOLD ESTIMATION USING NEURAL NETWORKS AND ITS APPLICATION TO PARALLEL SPEECH ENHANCEMENT
FORWARD MASKING THRESHOLD ESTIMATION USING NEURAL NETWORKS AND ITS APPLICATION TO PARALLEL SPEECH ENHANCEMENT T. S. GUNAWAN 1, O. O. KHALIFA 1, E. AMBIKAIRAJAH 2 1 Electrical and Coputer Engineering Departent,
More informationStudy of Turbo Coded OFDM over Fading Channel
International Journal of Engineering Research and Development e-issn: 2278-067X, p-issn: 2278-800X, www.ijerd.com Volume 3, Issue 2 (August 2012), PP. 54-58 Study of Turbo Coded OFDM over Fading Channel
More informationChalmers Publication Library
Chalers Publication Library HARQ Feedback in Spectru Sharing Networks This docuent has been downloaded fro Chalers Publication Library CPL. It is the author s version of a work that was accepted for publication
More informationChannel Estimation for Downlink LTE System Based on LAGRANGE Polynomial Interpolation
Channel Estimation for Downlink LTE System Based on LAGRANGE Polynomial Interpolation Mallouki Nasreddine,Nsiri Bechir,Walid Hakimiand Mahmoud Ammar University of Tunis El Manar, National Engineering School
More informationMIMO in 3G STATUS. MIMO for high speed data in 3G systems. Outline. Information theory for wireless channels
MIMO in G STATUS MIMO for high speed data in G systems Reinaldo Valenzuela Wireless Communications Research Department Bell Laboratories MIMO (multiple antenna technologies) provides higher peak data rates
More informationEnhanced Uplink Dedicated Channel (EDCH) High Speed Uplink Packet Access (HSUPA)
Enhanced Uplink Dedicated Channel (EDCH) High Speed Uplink Packet Access (HSUPA) EDCH Background & Basics Channels/ UTRAN Architecture Resource Management: Scheduling, Handover Performance Results Background
More informationPARAMETER OPTIMIZATION OF THE ADAPTIVE MVDR QR-BASED BEAMFORMER FOR JAMMING AND MULTIPATH SUPRESSION IN GPS/GLONASS RECEIVERS
PARAMETER OPTIMIZATION OF THE ADAPTIVE MVDR QR-BASED BEAMFORMER FOR JAMMING AND MULTIPATH SUPRESSION IN GPS/GLONASS RECEIVERS V. Behar 1, Ch. Kabakchiev 2, G. Gaydadjiev 3, G.Kuzanov 4, P. Ganchosov 5
More informationAn HARQ scheme with antenna switching for V-BLAST system
An HARQ scheme with antenna switching for V-BLAST system Bonghoe Kim* and Donghee Shim* *Standardization & System Research Gr., Mobile Communication Technology Research LAB., LG Electronics Inc., 533,
More informationDesign of HSDPA System with Turbo Iterative Equalization
Abstract Research Journal of Recent Sciences ISSN 2277-2502 Design of HSDPA System with Turbo Iterative Equalization Kilari. Subash Theja 1 and Vaishnavi R. 1 Joginpally B R Engineering college 2 Vivekananda
More informationInterference Management in LTE Femtocell Systems Using Fractional Frequency Reuse
Interference Manageent in LTE Fetocell Systes Using Fractional Frequency Reuse Poongup Lee and Jitae Shin School of Inforation and Counication Engineering Sungyunwan University, Suwon, 440-746, Korea {poongup,
More informationConstruction and Analysis of Quaternion MIMO-OFDM Communications Systems
JOURNAL OF COMMUNICATION AND INFORMATION SYSTEMS, VOL. 32, NO.1, 2017. 80 Construction and Analysis of Quaternion MIMO-OFDM Counications Systes L.G.P. Meloni, J.L. Hinostroza N., and O. Torena Jr. Abstract
More information