Bibliografias temáticas / Variable spreading factor

Índice

Artigos de revistas
Teses / dissertações
Capítulos de livros
Trabalhos de conferências

Literatura científica selecionada sobre o tema "Variable spreading factor"

Autor: Grafiati

Publicado: 4 de junho de 2021

Última modificação: 12 de fevereiro de 2022

Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos

Selecione um tipo de fonte:

Consulte a lista de atuais artigos, livros, teses, anais de congressos e outras fontes científicas relevantes para o tema "Variable spreading factor".

Ao lado de cada fonte na lista de referências, há um botão "Adicionar à bibliografia". Clique e geraremos automaticamente a citação bibliográfica do trabalho escolhido no estilo de citação de que você precisa: APA, MLA, Harvard, Chicago, Vancouver, etc.

Você também pode baixar o texto completo da publicação científica em formato .pdf e ler o resumo do trabalho online se estiver presente nos metadados.

Artigos de revistas sobre o assunto "Variable spreading factor"

LEE, DONG-HAHK. "LOGIC DESIGN OF ORTHOGONAL VARIABLE SPREADING FACTOR CODE GENERATOR". Journal of Circuits, Systems and Computers 14, n.º 03 (junho de 2005): 507–13. http://dx.doi.org/10.1142/s0218126605002398.

Texto completo da fonte

Resumo:

This letter presents a new architecture for othogonal variable spreading factor (OVSF) code generator. The basic idea of the proposed method is to generate the code sequence using the outputs of binary counter and the binary representation of the code number. The proposed architecture can generate the code sequences as adding the only combinational logic circuits without an additional counter, if other code sequences are required according to SFs. Since the proposed generator is applied to W-CDMA modem that used different SFs simultaneously, it contributes to the reduction of the modem hardware complexity.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Takaoka, S., e F. Adachi. "HARQ with variable spreading factor for multicode MC-CDMA". Electronics Letters 42, n.º 2 (2006): 103. http://dx.doi.org/10.1049/el:20063285.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

MATSUSHIMA, Tomoko K., e Shoichiro YAMASAKI. "Complex Orthogonal Variable Spreading Factor Codes Based on Polyphase Sequences". IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences E103.A, n.º 10 (1 de outubro de 2020): 1218–26. http://dx.doi.org/10.1587/transfun.2019dmp0007.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Ballesteros, Dora M., Diego Renza e Jimmy Peña. "Entropy-based image encryption using Orthogonal Variable Spreading Factor (OVSF)". Ingeniería e Investigación 40, n.º 3 (17 de setembro de 2020): 70–80. http://dx.doi.org/10.15446/ing.investig.v40n3.81421.

Texto completo da fonte

Resumo:

The purpose of image encryption is to provide data privacy and security. The former ensures that only authorized personnel can access the original content, while the latter implies that there is no evident relationship between the encrypted and the original content, and that the key space is equally likely and large enough. In the current state of the field, there are several proposals of image encryption techniques with very high privacy (in terms of entropy) but weak in terms of security (i.e., small key space). Recently, a new encoding-based method that provides a long key space (namely 8,57 × 10506) with a middle value of entropy (87%) was proposed. Our proposal preserves the strength of the image encryption methods based on encoding, but with a higher value placed on security than the preliminary works. Every pixel of an image is mapped into an orthogonal code based on 256 bits. The 8-OVSF codes are selected to encode the image, given that the entropy of the inter-symbol is near the possible maximum. Numerous test results verify that our ciphered data have a very high value of entropy (98,5%) with an equally likely and long key space (8,57 × 10506), thus providing an adequate balance between privacy and security.

Estilos ABNT, Harvard, Vancouver, APA, etc.

MAEDA, N. "Variable Spreading Factor-OFCDM with Two Dimensional Spreading that Prioritizes Time Domain Spreading for Forward Link Broadband Wireless Access". IEICE Transactions on Communications E88-B, n.º 2 (1 de fevereiro de 2005): 487–98. http://dx.doi.org/10.1093/ietcom/e88-b.2.487.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Miyazawa, Takaya, e Iwao Sasase. "Multirate Spectral Phase-Encoded Time-Spreading O-CDMA System Using Orthogonal Variable Spreading Factor Code Sequences". IEEE Photonics Technology Letters 19, n.º 19 (outubro de 2007): 1502–4. http://dx.doi.org/10.1109/lpt.2007.903876.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Boariu, A., e R. E. Ziemer. "Multiuser detection in multipath environments for variable spreading-factor CDMA systems". IEEE Transactions on Communications 49, n.º 9 (2001): 1520–24. http://dx.doi.org/10.1109/26.950338.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Thit Minn e Kai-Yeung Siu. "Dynamic assignment of orthogonal variable-spreading-factor codes in W-CDMA". IEEE Journal on Selected Areas in Communications 18, n.º 8 (agosto de 2000): 1429–40. http://dx.doi.org/10.1109/49.864008.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Yang, Y., e T. S. P. Yum. "Maximally Flexible Assignment of Orthogonal Variable Spreading Factor Codes for Multirate Traffic". IEEE Transactions on Wireless Communications 3, n.º 3 (maio de 2004): 781–92. http://dx.doi.org/10.1109/twc.2004.827765.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Puri, Parul, e Neetu Singh. "Two-dimensional spreading scheme employing 2D orthogonal variable spreading factor codes for orthogonal frequency and code division multiplexing systems". IET Communications 7, n.º 5 (26 de março de 2013): 463–70. http://dx.doi.org/10.1049/iet-com.2012.0197.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Mais fontes

Teses / dissertações sobre o assunto "Variable spreading factor"

Kunnari, E. (Esa). "Multirate MC-CDMA:performance analysis in stochastically modeled correlated fading channels, with an application to OFDM-UWB". Doctoral thesis, University of Oulu, 2008. http://urn.fi/urn:isbn:9789514288098.

Texto completo da fonte

Resumo:

Abstract Multicarrier and multiple input–multiple output (MIMO) techniques have become popular in wireless communications over multipath fading channels in recent years. This thesis firstly considers the characterization and simulation of fading mobile radio channels for MIMO multicarrier systems. Secondly, the performance of spread-spectrum multicarrier (MC) code-division multiple-access (CDMA) with multirate transmission is analyzed. Thirdly, the analysis is applied to ultra-wideband (UWB) orthogonal frequency-division multiplexing (OFDM) systems enhanced with frequency-domain code-division multiplexing (CDM). The response of a small-scale fading channel is derived as a function of time, transmit and receive antenna positions, and subcarrier frequency, which leads to a tapped delay-line model with time-, space-, and frequency-selective taps. The taps are modeled as a sum of a deterministic line-of-sight or dominant scattered path and a zero-mean Gaussian part composed of a number of unresolvable scattered paths and, therefore, are Rice fading. The Gaussian parts have the desired temporal and spatiospectral correlations generated by time-correlation shaping filtering and a space-frequency correlation transformation, respectively. The simulator achieves a good accuracy while retaining a reasonable computational complexity. The generic performance analysis of MC-CDMA includes both the multicode and variable spreading factor (VSF) multirate schemes that are inherent for CDMA and capable of providing efficient support for services of different required data rates. The analysis also takes into account the intersymbol interference caused by the multipath delay components exceeding a guard interval, which is commonly omitted in the literature by assuming the guard interval to be longer than the maximum delay spread. Results comparing and pointing out notable differences in the error rate performance of the two multirate schemes in conjunction with six different combining techniques are presented for a synchronous downlink and both a synchronous and asynchronous uplink. The analysis of CDM-enhanced OFDM-UWB involves first a single piconet with different combinations of the VSF and multicode schemes. Frequency-domain spreading is found to improve the performance remarkably when a sufficient spreading factor and a suitable subcarrier combining method are used. Subsequently, CDMA of simultaneously operating piconets (SOPs) with either the VSF or multicode scheme is considered. While both multirate schemes result in a similar performance when the number of SOPs is large, notable differences arise when there are only a few SOPs.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Tsai, Yung-Chiuan, e 蔡勇權. "Novel Partial-Orthogonal Variable Spreading Factor Code for MC-DS-CDMA Systems". Thesis, 2007. http://ndltd.ncl.edu.tw/handle/70284822497885569565.

Texto completo da fonte

Resumo:

碩士
立德管理學院
應用資訊研究所
95
In the mobile communication technologies of the 3rd Generation Partner-ship Project (3GPP), there is a wideband digital technology named WCDMA (Wideband Code Division Multiple Access). WCDMA systems have offered opportunities to provide variable user data rates and flexibly support applications with different bandwidth requirements. Code-Division Multiple-Access (CDMA) techniques allow many users to transmit simultaneously in the same band without substantial interference by using approximately orthogonal spread-spectrum waveforms. In the technology of data channelize, Orthogonal Variable Spreading Factor (OVSF) code can distinguish the different data tunnels and promise the orthogonality for different customer tunnels or the same customer but different business tunnels. Furthermore, this technology allows users apply the same frequency to translate information and undisturbed by each other. Orthogonal variable spreading factor code (OVSF) code is employed as channelization codes for multirate transmission in MC-DS-CDMA system. However, mother/child code blocking resulted in a major drawback of traditional OVSF codes significantly impact on reducing bandwidth utilization of the systems. This thesis presents a novel two-dimensional Partial-Orthogonal Variable Spreading Factor (POVSF) code in order to support quite larger number code candidates for more people used in multirate system. In order to improve efficiency of channel, we use full and partial orthogonal properties to offer higher numbers of users and more opportunities to flexibly support applications with different bandwidth requirements. Simulation result reveals that low rejection probability of POVSF code can nearly neglect the blocking problem as code assignment.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Capítulos de livros sobre o assunto "Variable spreading factor"

Atarashi, Hiroyuki, e Mamoru Sawahashi. "Variable Spreading Factor Orthogonal Frequency and Code Division Multiplexing (VSF-OFCDM)". In Multi-Carrier Spread-Spectrum & Related Topics, 113–22. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/978-1-4757-3569-7_11.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

"Adaptive DS-CDMA Networking Using Variable Spreading Factors and Beamforming". In Single- and Multi-Carrier DS-CDMA, 929–78. Chichester, UK: John Wiley & Sons, Ltd, 2004. http://dx.doi.org/10.1002/0470863110.ch23.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

El Hidan, Moulay Abdelmonaim, Kholoud Kahime, Aimrane Abdelmohcine, Abdellatif Abbaoui, Mohamed Echchakery, Ahmed Draoui, Hicham Chatoui et al. "Biology, Epidemiology, and Public Health Significance of Malaria Disease Linked to Climate Changes". In Advances in Environmental Engineering and Green Technologies, 389–406. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-7775-1.ch020.

Texto completo da fonte

Resumo:

Malaria is a mosquito-borne infectious disease caused by obligate intraerythrocytic protozoa of the genus Plasmodium. As one of the most devastating global health issues, malaria is a sensitive disease to weather and climate conditions, in such a way the ongoing trends of increasing temperature and more variable weather could lead to malaria transmission spreading. Spatial and temporal variations in precipitation, temperature, and humidity that are projected to take place under different climate change scenarios will impact the biology and ecology of malaria vectors and subsequently the risk of disease transmission. Here, the authors review how climate and climate change may impact malaria transmission. They contrast ecological and behavioral characteristics of malaria vectors and parasites and how weather, climate, climate change, and socioeconomic factors may have very different impacts on their spatiotemporal occurrence and abundance and the resulting malaria risk.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Jiménez Sánchez, Álvaro, Eliza Carolina Vayas Ruiz, Víctor Hugo Guachimbosa Villalba e María Rosa Frontera Sánchez. "Analysis of the Approach to Online Advertising of Leading Sportswear Brands". In Research Anthology on Business Strategies, Health Factors, and Ethical Implications in Sports and eSports, 193–214. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-7707-3.ch012.

Texto completo da fonte

Resumo:

Brands like Nike or Adidas are predominant in almost every country. One of the keys of their success is due to the investment in advertisement and to their different strategies of promotion. This research analyzed 117 ads of five important sports brands (Nike, Adidas, Puma, Reebok, and Converse) with the higher number of views in YouTube. Within the numerous variables, the study of the main important characters, the duration of the advertising, the year or decade of creation, the presence of violence, the context or environment where they were developed, the gender that is predominant (masculine or feminine), or the character's age stand out. The results showed that women still have a secondary role in sport advertisement and that younger and celebrities have the leading role, especially in the football scope, in the majority of the observed videos. It is concluded that brands are increasingly stand up for the feminine public and gradually are spreading out in the search of new market niches in order to keep innovation in promoting youth trends with this sport brands as promoters.

Estilos ABNT, Harvard, Vancouver, APA, etc.

El Hidan, Moulay Abdelmonaim, Kholoud Kahime, Mehdi Ait Laaradia, Btissam Bouimeja, Fadoua Aabadi, Abdellaziz Ait Mansour, Oulaid Touloun e Abderrahman Chait. "Climate Change, Scorpion Ecology, and Envenomation". In Advances in Environmental Engineering and Green Technologies, 460–74. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-7775-1.ch023.

Texto completo da fonte

Resumo:

Every year, more than 1 million cases of scorpion envenomation are reported worldwide. Scorpions are thermophilic organisms. They are sensitive to weather and climate conditions, in such a way the ongoing trends of increasing temperature and more variable weather could lead to scorpionism spreading. There has been considerable debate as to whether global envenomation will be impacted by climate change which has focused on snake and spider envenomation risk. This debate didn't give enough interest to scorpion stings and its burden risks, in spite their widespread potential effects in many regions. Here, the authors review how climate and climate change may impact scorpion activity as well as scorpion envenomation. They contrast ecological and behavioral characteristics of these arthropods, and how weather, climate, climate change, and socioeconomic factors may have very different impacts on the spatiotemporal occurrence and abundance of scorpions, and the resulting scorpion envenomation.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Trabalhos de conferências sobre o assunto "Variable spreading factor"

Zhang, Lijia, Xiangjun Xin, Bo Liu, Chongxiu Yu e Yongjun Wang. "Next Generation ECDM-OFDM based Passive Optical Network with Variable Spreading Factor". In National Fiber Optic Engineers Conference. Washington, D.C.: OSA, 2012. http://dx.doi.org/10.1364/nfoec.2012.jth2a.63.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Yingming Tsai, Guodong Zhang e Xiaodong Wang. "Variable spreading factor orthogonal polyphase codes for constant envelope OFDM-CDMA system". In IEEE Wireless Communications and Networking Conference, 2006. WCNC 2006. IEEE, 2006. http://dx.doi.org/10.1109/wcnc.2006.1696491.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Li, Dong, e Jiang Fei Bo. "Design of the DS-UWB Communication System Based on Chaotic Variable Spreading Factor". In 2011 Seventh International Conference on Computational Intelligence and Security (CIS). IEEE, 2011. http://dx.doi.org/10.1109/cis.2011.163.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Khalid, L., e A. Anpalagan. "Effect of Carrier Frequency Offset on the BER Performance of Variable Spreading Factor OFCDM Systems". In 2008 IEEE International Conference on Communications. IEEE, 2008. http://dx.doi.org/10.1109/icc.2008.945.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Bakura, M. U. M., Jing Xiaojun e Sun Songling. "An Improved Region Division Allocation of Orthogonal Variable Spreading Factor Code in the Forward Link of WCDMA Network". In 2013 International Conference on Communication Systems and Network Technologies (CSNT 2013). IEEE, 2013. http://dx.doi.org/10.1109/csnt.2013.91.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Khedr, Mohamed E., Roshdy A. AbdelRasoul e Mahmoud M. Youssef. "Efficient Utilization of Orthogonal Variable Spreading Factor Trees Using Two levels Of Hierarchies and Adaptive Rate Control Mechanism". In 2007 Innovations in Information Technologies (IIT). IEEE, 2007. http://dx.doi.org/10.1109/iit.2007.4430438.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Sheikh, Javaid A., Shabir A. Parah, Uzma Sakeena Akhtar, A. Mueed Hafiz e G. Mohiuddin Bhat. "Orthogonal Variable Spreading Factor (OVSF) based image transmission using Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) system". In 2012 International Conference on Communications, Devices and Intelligent Systems (CODIS). IEEE, 2012. http://dx.doi.org/10.1109/codis.2012.6422132.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Wang, W., H. H. Qiu e P. Cheng. "Deformation and Solidification of Droplet Impact With Variable Thermal Contact Resistance". In ASME 2003 Heat Transfer Summer Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/ht2003-47056.

Texto completo da fonte

Resumo:

Interfacial thermal contact resistance between the impinging flow of a molten droplet and a substrate, which is qualified by thermal contact conductance, plays an important role in the spreading and solidification of a droplet. In the present study, a simple correlation for the thermal contact conductance in the rapid contact solidification process was developed. With this correlation being directly used in numerical simulation, for the first time, a variable thermal contact resistance was taken into consideration to simulate both the dynamics and phase change responses during a molten droplet impingement. Numerical results were compared with that of the cases when thermal contact resistance was zero or a constant. The changes in spread factor with time and thermal contact conductance indicated that predictions from the computer simulation were sensitive to the values of thermal contact resistance. Experiment was conducted to demonstrate the validity of the present study. Comparison results showed that rather than using a constant average value, better agreement between the experimental and numerical results would be obtained if a variable thermal contact resistance were used in the numerical simulation.

Estilos ABNT, Harvard, Vancouver, APA, etc.

Farrokhi, Gh, S. Zokaei e H. A. Rohi. "Performance of the MC-DS-CDMA Systems with PCE and Variable Spreading Factors". In 2009 5th International Conference on Wireless Communications, Networking and Mobile Computing (WiCOM). IEEE, 2009. http://dx.doi.org/10.1109/wicom.2009.5303501.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Tempiem, Phanupong, e Rardchawadee Silapunt. "Quantile Classification of Variance from the Mean for Spreading Factor Allocation in LoRaWAN". In 2020 5th International Conference on Information Technology (InCIT). IEEE, 2020. http://dx.doi.org/10.1109/incit50588.2020.9310964.

Texto completo da fonte

Estilos ABNT, Harvard, Vancouver, APA, etc.

Oferecemos descontos em todos os planos premium para autores cujas obras estão incluídas em seleções literárias temáticas. Contate-nos para obter um código promocional único!