发布求助
文献互助 智能选刊 最新文献

2014 International Telecommunications Symposium (ITS)最新文献

筛选
英文 中文
Efficient Frequency Domain Zadoff-Chu generator with application to LTE and LTE-A systems 高效频域Zadoff-Chu发生器在LTE和LTE- a系统中的应用
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-11-06 DOI: 10.1109/ITS.2014.6947990
F. A. D. de Figueiredo, Fabiano S. Mathilde, Fabbryccio A. C. M. Cardoso, Rafael M. Vilela, J. P. Miranda
{"title":"Efficient Frequency Domain Zadoff-Chu generator with application to LTE and LTE-A systems","authors":"F. A. D. de Figueiredo, Fabiano S. Mathilde, Fabbryccio A. C. M. Cardoso, Rafael M. Vilela, J. P. Miranda","doi":"10.1109/ITS.2014.6947990","DOIUrl":"https://doi.org/10.1109/ITS.2014.6947990","url":null,"abstract":"This paper presents a configurable and optimized hardware architecture for computing Zadoff-Chu (ZC) complex sequences in the Frequency Domain (FD). It is a hardware-efficient and accurate architecture for computing ZC sequences in real-time. The architecture is mainly based on the CORDIC algorithm for computing complex exponentials using only shift and add operations. Due to transformations applied to the Zadoff-Chu equation it is possible to eliminate the use of multipliers with non-constant terms. This hardware architecture is employed by the Physical Random Access Channel (PRACH) in LTE and LTE-A systems during the reception and detection of random access preambles. Its main advantage is that it eliminates the need for storing a large number of long complex ZC sequences.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130960025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 7
On supervised channel estimation techniques for very large MIMO communication systems 超大型MIMO通信系统的监督信道估计技术
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-11-06 DOI: 10.1109/ITS.2014.6948023
Igor Sousa Osterno, Diego Sousa Aguiar, C. Fernandes
{"title":"On supervised channel estimation techniques for very large MIMO communication systems","authors":"Igor Sousa Osterno, Diego Sousa Aguiar, C. Fernandes","doi":"10.1109/ITS.2014.6948023","DOIUrl":"https://doi.org/10.1109/ITS.2014.6948023","url":null,"abstract":"This paper compares and assesses the performance of different channel estimation techniques for multicell multiuser multiple-input multiple-output (MIMO) systems in a very large (VL) MIMO scenario. Some of these techniques exploit properties of large random matrices and are less affected by pilot contamination, which is the case of the technique based on the eingenvalue decomposition (EVD) of the output covariance matrix. Other techniques do not exploit such properties and are more sensitive to errors as the number of antenna sensors grow large, which is the case of the classical least squares (LS) method. Our main goal is to investigate the use of those techniques in a VL-MIMO system under different scenarios. This paper also proposes a new method to solve the multiplicative matrix ambiguity of the EVD-based method by using a simple Khatri-Rao product. Numerical results are shown to atest the increased effectiveness of the EVD-based channel estimation in a VL-MIMO environment.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124354726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
An efficient and simple algorithm for estimating the number of sources via ℓ0.55-norm 一种利用0.55范数估计信源数的简单有效算法
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-11-06 DOI: 10.1109/ITS.2014.6947967
D. Guimarães, Giovanni Henrique Faria Floriano, Rausley Adriano Amaral de Souza
{"title":"An efficient and simple algorithm for estimating the number of sources via ℓ0.55-norm","authors":"D. Guimarães, Giovanni Henrique Faria Floriano, Rausley Adriano Amaral de Souza","doi":"10.1109/ITS.2014.6947967","DOIUrl":"https://doi.org/10.1109/ITS.2014.6947967","url":null,"abstract":"Recently, it has been proposed an empirical method for estimating the number of sources of signals impinging on multiple sensors, named norm-based (NB) algorithm. The algorithm computes the Euclidian norm of vectors whose elements are the normalized and nonlinearly scaled eigenvalues of the received signal covariance matrix, and the corresponding normalized indexes. Such norms are then used to discriminate the largest eigenvalues from the remaining ones, thus allowing for the estimation of the number of sources. In this paper we propose an improved norm-based (iNB) algorithm which uses the ℓ0.55-norm as a means for classifying the eigenvalues. Differently from the NB, the iNB algorithm does not use the nonlinear scaling and does not need to set an additional empirical constant that is crucial to the proper operation of the NB algorithm. Comparisons are made with the estimators MDL (minimum description length) and AIC (Akaike information criterion), and with a recently-proposed estimator based on the random matrix theory (RMT). It is shown that the iNB algorithm can outperform one or more of these estimators in several situations, and that it always outperforms the NB algorithm.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115223269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Channel estimation using neural network in Orthogonal Frequency Division Multiplexing-Interleave Division Multiple Access (OFDM-IDMA) system 基于神经网络的正交频分复用-交错多址(OFDM-IDMA)系统信道估计
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-11-06 DOI: 10.1109/ITS.2014.6947977
Şakir Şimşir, N. Taspinar
{"title":"Channel estimation using neural network in Orthogonal Frequency Division Multiplexing-Interleave Division Multiple Access (OFDM-IDMA) system","authors":"Şakir Şimşir, N. Taspinar","doi":"10.1109/ITS.2014.6947977","DOIUrl":"https://doi.org/10.1109/ITS.2014.6947977","url":null,"abstract":"In this paper, channel estimation based on neural network trained by Levenberg-Marquardt Algorithm is proposed to estimate the channel coefficients in Orthogonal Frequency Division Multiplexing-Interleave Division Multiple Access (OFDM-IDMA) systems. Conventional pilot based channel estimation algorithms like Minimum Mean Square Error (MMSE) and Least Squares (LS) are also utilized to make comparison with our proposed method with the help of bit error rate (BER) and mean square error (MSE) graphs. In this study, it is demonstrated with the computer simulations that, channel estimation based on neural network ensures better performance than LS algorithm without the requirement of channel statistics and noise information which MMSE algorithm needs to estimate the channel coefficients. Even though MMSE algorithm still shows the best performance in channel estimation, our proposed method has the advantage of being less complex and easy to apply. Because of being multiuser system, the performance of OFDM-IDMA is also evaluated for different user numbers under the channel estimation employing LS, MMSE and neural network methods, respectively. It is shown that the system performance decreases as long as the number of user is increased.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124871914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 9
A Genetic Algorithm based approach for resource allocation in LTE uplink 基于遗传算法的LTE上行链路资源分配方法
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-11-06 DOI: 10.1109/ITS.2014.6947956
Saulo Henrique da Mata, P. R. Guardieiro
{"title":"A Genetic Algorithm based approach for resource allocation in LTE uplink","authors":"Saulo Henrique da Mata, P. R. Guardieiro","doi":"10.1109/ITS.2014.6947956","DOIUrl":"https://doi.org/10.1109/ITS.2014.6947956","url":null,"abstract":"LTE has become the de facto technology for the 4G networks. It offers unprecedented data transmission and low latency for several types of applications and services. In this paper, we investigate the resource allocation in the LTE uplink, which is widely known as a complex optimization problem. To solve this issue, we present a new scheduling algorithm based on Genetic Algorithms (GA). The proposed algorithm is evaluated using NS-3 in scenarios of video transmission with focus on video chat. The performance of the GA based algorithm is compared with the most relevant algorithms present in the literature. Simulation results show the superiority of the GA based approach to offer better video quality in the scenarios of evaluation.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124895824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 10
A priori selection of high accuracy mobile station position estimates 高精度移动站位置估计的先验选择
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-11-06 DOI: 10.1109/ITS.2014.6947960
Rafael Saraiva Campos, LISANDRO LOVISOLO
{"title":"A priori selection of high accuracy mobile station position estimates","authors":"Rafael Saraiva Campos, LISANDRO LOVISOLO","doi":"10.1109/ITS.2014.6947960","DOIUrl":"https://doi.org/10.1109/ITS.2014.6947960","url":null,"abstract":"A priori identification and selection of high accuracy position estimates, i.e., with error below 100 meters, is particularly relevant for critical location-based applications, like vehicle tracking and, specially, emergency call positioning. This work presents a backpropagation artificial neural network classifier used to predict the accuracy of mobile station position estimates produced by a network-based radio-frequency fingerprinting method, RF-FING+RTD-PRED (Predicted Radio-frequency Fingerprint with Round Trip Delay), previously formulated by the authors. The classifier employs the same radio-frequency parameters used by the aforementioned method plus some additional network data. In field tests carried out in GSM (Global System for Mobile Communications) networks in urban and suburban areas, where 6600 measurement reports have been collected, a 89% precision in the identification of high accuracy position estimates has been achieved. The presented method is promptly extensible to 3G cellular networks.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125362428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Design and analysis of microstrip antenna arrays for meteorological nano-satellites for UHF uplink 气象纳米卫星超高频上行微带天线阵列设计与分析
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-11-06 DOI: 10.1109/ITS.2014.6947985
M. P. Magalhães, M. Heckler, J. Mota, A. Sombra, E. C. Moreira
{"title":"Design and analysis of microstrip antenna arrays for meteorological nano-satellites for UHF uplink","authors":"M. P. Magalhães, M. Heckler, J. Mota, A. Sombra, E. C. Moreira","doi":"10.1109/ITS.2014.6947985","DOIUrl":"https://doi.org/10.1109/ITS.2014.6947985","url":null,"abstract":"This paper presents the study of microstrip antenna arrays for meteorological nano-satellites that are under development in the frame of UNIESPAÇO programme, which is supported by the Brazilian Space Agency (AEB). The main goal of such satellites is to serve as data relay for transmission of meteorological data collected by stations deployed in remote areas, such as in the rain forest, whereby no wired communication is possible. Arrays composed of linearly and circularly polarized microstrip antennas are investigated. The performance of such arrays is assessed including parameter variations, especially for the case of dielectric constant of the antenna substrate and misalignment in the orientation of the array elements. Such imperfections can occur due to mechanical stress and large temperature variations that are typical to the space environment. The antennas were modeled with the electromagnetic simulator Ansys HFSS. Good results have been observed in terms of the axial ratio, impedance bandwidth and gain for both of the proposed models.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"148 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121371619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 7
Investigating the use of modulation spectral features within an i-vector framework for far-field automatic speaker verification 研究在远场自动扬声器验证的i向量框架内使用调制光谱特征
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-11-06 DOI: 10.1109/ITS.2014.6948012
Anderson R. Avila, F. Fraga, M. Sarria-Paja, T. Falk
{"title":"Investigating the use of modulation spectral features within an i-vector framework for far-field automatic speaker verification","authors":"Anderson R. Avila, F. Fraga, M. Sarria-Paja, T. Falk","doi":"10.1109/ITS.2014.6948012","DOIUrl":"https://doi.org/10.1109/ITS.2014.6948012","url":null,"abstract":"It is known that channel variability compromises automatic speaker recognition accuracy. However, little attention has been given so far to the detrimental effects encountered under reverberant environments. In this paper, we focus on the issue of automatic speaker verification (ASV) under several levels of room reverberation. Alternative auditory inspired features are explored. Specifically, we investigate whether the performance of the so-called modulation spectral features (MSFs) can overcome the well-known mel-frequency cepstral coefficients (MFCCs). Experiments were conducted with an ASV system based on the state-of-the-art i-vector. The main contribution of this paper is to verify if MSFs combined with i-vectors are able to present the same performance encountered in the literature regarding speech recognition and speaker identification systems in reverberant environment.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116504482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Design of lattice network codes based on Construction D 基于Construction的格网代码设计
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-11-06 DOI: 10.1109/ITS.2014.6947986
Paulo Ricardo Branco da Silva, Danilo Silva
{"title":"Design of lattice network codes based on Construction D","authors":"Paulo Ricardo Branco da Silva, Danilo Silva","doi":"10.1109/ITS.2014.6947986","DOIUrl":"https://doi.org/10.1109/ITS.2014.6947986","url":null,"abstract":"Physical-layer network coding (PNC) takes advantage of signal interference to transmit linearly combined data from multiple nodes. Nazer and Gastpar introduced the use of nested lattice codes to network coding by demonstrating that linear combination according to channel dependent integer coefficients provides an effective coding scheme. Feng et al. presented an algebraic approach for this strategy based on modules. They developed practical design guidelines, especially for Construction A. This paper intends to show the same possibilities for lattices built with the multilevel Construction D. We know from Feng et al. that Construction D achieves higher coding gains than A and also that multilevel codes can construct large modulations from simple level codes. We present a multi-stage decoder with a modified Viterbi metric for lattice decoding. Simulation results verify the scheme's feasibility for a 64-QAM with effective rate of 5 bits per complex dimension (b/cdim) and for a 16-QAM with effective rate of 3 b/cdim.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121771459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 9
All-optical narrowband spectral slicing encryption with super-Gaussian filters 全光窄带频谱切片加密与超高斯滤波器
2014 International Telecommunications Symposium (ITS) Pub Date : 2014-11-06 DOI: 10.1109/ITS.2014.6947965
C. Martins, Carlos A. Messani, Cleiton J. Alves, E. Fagotto, M. Abbade
{"title":"All-optical narrowband spectral slicing encryption with super-Gaussian filters","authors":"C. Martins, Carlos A. Messani, Cleiton J. Alves, E. Fagotto, M. Abbade","doi":"10.1109/ITS.2014.6947965","DOIUrl":"https://doi.org/10.1109/ITS.2014.6947965","url":null,"abstract":"Recent literature points out the benefits of encrypting signals in the physical layer to improve network security. In particular, a novel all-optical encryption approach uses narrowband optical band-pass filters (OBPF) to split a dense wavelength division multiplexing (DWDM)-compatible signal into several spectral slices which, then, have their physical properties, such as phase and delay, altered; as a result, after multiplexing all slices, an encoded version of the input signal is obtained. The performance of such technique was previously evaluated by assuming that all OBPFs are characterized by ideal rectangular-shaped transfer functions. In this work, we investigate how such performance is affected by the utilization of practical OBPFs with super-Gaussian profiles. Simulation results indicate that there is a trade-off between the filter bandwidth and filter order that may allow for encrypted signals to be properly decoded even after propagation distances up to 400 km, which is typical metropolitan area network distance.","PeriodicalId":359348,"journal":{"name":"2014 International Telecommunications Symposium (ITS)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121957216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
首页 上一页 下一页 尾页
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整，为了账户安全，请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们：info@booksci.cn Book学术提供免费学术资源搜索服务，方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号：604180095
Book学术官方微信