Academic literature on the topic 'Time division duplex TDD'

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Journal articles on the topic "Time division duplex TDD"

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Al-awadi, Aws Majeed, and Mohammed Jawad Al-dujaili. "Simulation of LTE-TDD in the HAPS channel." International Journal of Electrical and Computer Engineering (IJECE) 10, no. 3 (June 1, 2020): 3152. http://dx.doi.org/10.11591/ijece.v10i3.pp3152-3157.

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LTE stands for Long Term Evolution. This technology enhances the data rate and capacity using a new radio interface and an optimized core network. This progress was done to satisfy standards defined for the fourth generation of cellular communications in ITU. LTE has two types of transmission: Frequency Division Duplex (FDD) and Time Division Duplex (TDD). Nowadays, LTE-TDD rapidly Grows and takes place of old fixed cellular communications, like WiMAX. Another upcoming technology in the communication industry is High Amplitude Platform Stations (HAPS). Studying the capability of HAPS as a base station for LTE-TDD is the main purpose of this paper. Simulations have done using HAPS channel and compared to Stanford University Interim (SUI) standard channels for different scenarios. Results were compared to achieve a conclusion on HAPS implementation for LTE-TDD based on BER and data throughput.
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K.Venkatesh, G., and P. V.Rao. "Performance analysis of a novel method for fast handovers in TDD and FDD for long term evolution." International Journal of Engineering & Technology 7, no. 1.9 (March 1, 2018): 115. http://dx.doi.org/10.14419/ijet.v7i1.9.9745.

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The LTE Long Term Evolution highly developed Technology, Handover is the essential function of the mobility of user in cellular networks in Time Division Duplex as well as Frequency Division Duplex. Handover is one of the essential that can affect the [QoS] Quality of Service with Capacity of Mobile Broadband Networks. Within mobile cellular network communication systems, a (spectrum) limited shared resource needs to be shared with all the users, so full duplex communication is achieved. This paper involves studying diverse Hand over delay parameters and also focus on reducing “Hard Handover delay” by minimizing interruption time, activation time, wireless channel accesses time as well as the wireless link transmission delay. Technique is developed in order to reduce the handover delay time in Time Division Duplex network which too reduces the wireless channel access time and the wireless link transmission delay. A novel handover algorithm is developed which would decreases the handover delay time and access time inside mobile network environment.Additional work may be conceded on to obtain enhanced performance and Quality of service in Time Division Duplex mobile network.
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Sulaeman, Enceng, Yaya Sulaeman, and Asep Yudi Hercuadi. "Desain dan Implementasi Duplekser dengan Metoda Pseudo-Interdigital untuk Uplink dan Downlink LTE." Jurnal Elektronika dan Telekomunikasi 13, no. 2 (June 29, 2016): 73. http://dx.doi.org/10.14203/jet.v13.73-80.

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Duplekser merupakan perangkat yang dapat mengisolasi receiver dari transmitter saat keduanya saling berbagi antena yang sama, digunakan agar komunikasi bisa berjalan secara full duplex. Ada dua metode transmisi duplex yaitu frequency division duplex (FDD) dan time division duplex (TDD). FDD merupakan teknik duplex yang menggunakan dua frekuensi yang berbeda untuk melakukan komunikasi dalam dua arah, sedangkan TDD menggunakan frekuensi tunggal dan frekuensi tersebut digunakan oleh semua kanal untuk melakukan pengiriman dan penerimaan data. Gabungan dua bandpass filter dengan metoda pseudo-interdigital untuk aplikasi LTE (long term evolution). Metode ini lebih unggul dibandingkan duplekser dengan metoda hybrid. Duplekser bekerja pada FDD LTE band ke-7 yaitu frekuensi uplink 2500-2570 MHz dan downlink 2620-2690 MHz. Dari hasil pengukuran diperoleh sebagai berikut: nilai frekuensi center pada uplink 2639 MHz dan pada downlink 2659 MHz, insertion loss pada uplink 1,561 dB dan downlink 1,74 dB, bandwidth ±70 MHz, isolasi 23,03 dB, serta nilai return loss 23,5 dB pada uplink dan downlink 23,45 dB.
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Peng, Xidan, and Xiangyang Li. "Performance Analysis for Analog Network Coding with Imperfect CSI in FDD Two Way Channels." Journal of Systems Science and Information 3, no. 4 (August 25, 2015): 357–64. http://dx.doi.org/10.1515/jssi-2015-0357.

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AbstractA time-division duplex (TDD) two-way channel exploits reciprocity to estimate the forward channel gain from the reverse link. Many previous works explore outage probabilities in the TDD system, based on the reciprocity property. However, a frequency-division duplex (FDD) system has no reciprocity property. In this letter, we investigate the impact of CSI estimation error on the performance of non-orthogonal and orthogonal analog network coding protocols in an FDD two-way system, where channel gains are independent of each other. Considering imperfect CSI, the closed-form expressions of outage probabilities by two protocols are derived in the high signal-to-noise ratio (SNR) regime, respectively. It is shown that the derived outage probabilities match results of Monte Carlo simulations in different communication scenarios. It is interesting that ANC in the FDD two-way channel is proved to outperform that in the TDD channel by the computer simulation.
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Kalidoss, R., M. A. Bhagyaveni, and K. S. Vishvaksenan. "A Location-Based Duplex Scheme for Cost Effective Rural Broadband Connectivity Using IEEE 802.22 Cognitive Radio Based Wireless Regional Area Networks." Fluctuation and Noise Letters 13, no. 04 (October 20, 2014): 1450028. http://dx.doi.org/10.1142/s021947751450028x.

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The search for a method of utilizing the scarce spectrum in an efficient manner is an active area of research in both academic and industrial communities. IEEE 802.22 is a standard for wireless regional area network (WRAN) based on cognitive radio (CR) that operates over underutilized portions of TV bands (54–862 MHz). Time division duplex (TDD)-based WRAN cells have such advantages as dynamic traffic allocation, traffic asymmetry to users and ease of spectrum allocation. However, these cells suffer from severe cross time slot (CTS) interference when the frames of the cells are not synchronized with adjacent WRAN cells. In this paper, we evaluate the location-based duplex (LBD) scheme for eliminating the CTS interference. The proposed LBD system is much more flexible and efficient in providing asymmetric data service and eliminating CTS interference by exploiting the advantages of both TDD and frequency division duplex (FDD) schemes. We also compare the performance of LBD systems with virtual cell concepts. Furthermore, our simulation results reveal that LBD-based systems outperform the virtual cell approach in terms of the low signal-to-interference (SIR) ratio requirement by mitigating the effects of CTS.
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Xue, Linshan, Xue Li, Weiren Wu, and Yikang Yang. "Design of Tracking, Telemetry, Command (TT&C) and Data Transmission Integrated Signal in TDD Mode." Remote Sensing 12, no. 20 (October 13, 2020): 3340. http://dx.doi.org/10.3390/rs12203340.

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For satellite or aircraft networks, tracking, telemetry, and control (TT&C) and data transmission between different nodes are necessary. Traditional measurement mostly adopts the frequency division duplex (FDD) mode and uses a continuous measurement system to achieve high-precision measurement. However, as the number of network nodes increases, the mode suffers from complex frequency domain allocation, and high-cost measurement and data transmission equipment is required. This paper proposes the integrated signal in time division duplex (TDD) mode to improve frequency utilization to address these circumstances. The proposed signal can transmit the TT&C and data at the same frequency. In addition, the high-precision time-frequency synchronization and relative measurement technology in the TDD mode for distributed spacecraft or aircraft networks are studied. The simulation results show that the signal can work normally when the Doppler extrapolation error is less than a quarter of the integration frequency. The distance extrapolation error should be less than a quarter of the length of a chip. The integrated signal reduces the frequency band occupation and realizes the integration of TT&C and data transmission. In addition, the measurement performance is reduced by only 2~3 dB compared with that of the traditional pure TT&C signal.
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Shim, Yongwoon, and Dong-Hee Shin. "Analyzing the development of 4th generation mobile network in China: actor network theory perspective." info 17, no. 1 (January 12, 2015): 22–38. http://dx.doi.org/10.1108/info-09-2014-0041.

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Purpose – This paper aims to provide an in-depth analysis of the process of standards setting based on the case of long-term evolution time division duplex (LTE TDD) deployment in China. Design/methodology/approach – Using actor-network theory (ANT) as a theoretical framework, multi-level analyses are presented to explain the process of adoption of LTE TDD at a global level. Findings – Findings identified the complex interaction between the social and technical aspects of fourth-generation (4G) by highlighting the co-evolving nature, diversity and interface that constitute the next-generation network environment. Research limitations/implications – ANT provides a framework of ideas for describing the process of technology adoption and for developing stories that explain it. Originality/value – The findings shed light on a critical insight of the interrelationships between TD-SCDMA and LTE TDD and identify the policy successes and failures of 4G mobile networks.
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Hakim, N. F. A., T. Hariyadi, A. B. Pantjawati, and B. Mulyanti. "Analysis high gain waveguide slot antenna 2.3 GHz for Long Term Evolution-Time Division Duplex (LTE-TDD)." IOP Conference Series: Materials Science and Engineering 850 (May 23, 2020): 012054. http://dx.doi.org/10.1088/1757-899x/850/1/012054.

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Winarti, Titin. "SISTEM KOMUNIKASI SELULER DENGAN UNIVERSAL MOBILE TELEPHONE SYSTEM ( UMTS )." Jurnal Transformatika 4, no. 2 (January 30, 2007): 50. http://dx.doi.org/10.26623/transformatika.v4i2.19.

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<span>Sistem celuler GSM memiliki beberapa kekurangan, yaitu tidak mampu untuk mengintegrasikan layanan video call dan video streaming karena kecepatan data masih rendah. Dengan alasan itu, maka ETSI menentukan migrasi dari GSM ke sistem generasi seluler ketiga yang disebut dengan UMTS (Universal Mobile Telephone System). Adapun spektrum frekuensi UMTS terestrial bekerja pada 1920-1980 MHz, 2110-2170 MHz untuk dipasangkan dari band dan 1900-1920 MHz, 2010-2025 MHz untuk tidak berpasangan dari band Seiring dengan perkembangan teknologi, teknologi telekomunikasi sistem seluler terus berkembang dan menggarap sekarang telah mencapai generasi ketiga yang dikenal dengan nama dari International Mobile Telecommunications-2000 (IMT-2000). Adapun kerangka kerja untuk pengembangan teknologi seluler generasi ketiga (3G) di Eropa adalah Universal Mobile Telephone System (UMTS). UMTS menggunakan disebut oleh TD-CDMA multiple access adalah UTRA TDD (UMTS Terrestrial Radio Access dari Time Division Duplex) dan W-CDMA untuk UTRA FDD DARI (UMTS Terrestrial Radio Access dari Duplex Frekuensi Division Kata kunci : UMTS, multiple access, Sistem Seluler</span>
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Jiang, Zheng, Bin Han, Peng Chen, Fengyi Yang, and Qi Bi. "Design of Joint Spatial and Power Domain Multiplexing Scheme for Massive MIMO Systems." International Journal of Antennas and Propagation 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/368463.

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Massive Multiple-Input Multiple-Output (MIMO) is one of the key techniques in 5th generation wireless systems (5G) due to its potential ability to improve spectral efficiency. Most of the existing works on massive MIMO only consider Time Division Duplex (TDD) operation that relies on channel reciprocity between uplink and downlink channels. For Frequency Division Duplex (FDD) systems, with continued efforts, some downlink multiuser MIMO scheme was recently proposed in order to enable “massive MIMO” gains and simplified system operations with limited number of radio frequency (RF) chains in FDD system. However these schemes, such as Joint Spatial Division and Multiplexing (JSDM) scheme and hybrid precoding scheme, only focus on multiuser transmission in spatial domain. Different from most of the existing works, this paper proposes Joint Spatial and Power Multiplexing (JSPM) scheme in FDD systems. It extends existing FDD schemes from spatial division and multiplexing to joint spatial and power domain to achieve more multiplexing gain. The user grouping and scheduling scheme of JSPM is studied and the asymptotic expression for the sum capacity is derived as well. Finally, simulations are conducted to illustrate the effectiveness of the proposed scheme.
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Dissertations / Theses on the topic "Time division duplex TDD"

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Ustunel, Eser Kwon Hyuck M. "Time division duplex-wideband code division multiplex (TDD-WCDMA)." Diss., Click here for available full-text of this thesis, 2006. http://library.wichita.edu/digitallibrary/etd/2006/t029.pdf.

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Thesis (M.S.)--Wichita State University, Electrical and Computer Engineering.
"May 2006." Title from PDF title page (viewed on October 19, 2006). Thesis adviser: Hyuck M. Kwon. Includes bibliographic references (leaves 40-42).
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Peters, Gavin M. "Time Division Duplex (TDD) Multi-User Multiple-Input, Multiple-Output (MU-MIMO) Mobile Ad-Hoc Network(MANET)." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1563525886227608.

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Rada, Dominik. "Přenosová technologie G.mgfast." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2021. http://www.nusl.cz/ntk/nusl-442370.

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The master thesis deals with G.fast and G.mgfast transmission technologies, including their parameters. The work deals with the principle of vector DMT modulation and the possibility of time duplex TDD and full-duplex FDX in two-way communication used in these technologies. The following is a description of the line using the KHM model, which is suitable for simulations in the transmission band using G.fast and G.mgfast technologies. Subsequently, the disturbing effects of crosstalk at the near end of NEXT and the far end of FEXT and their elimination with these technologies are discussing. Part of the work explains supporting calculations to determine the SNR and bit allocation to calculate the baud rate. The work describes the methods of compensation of crosstalk FEXT and NEXT, which affect the resulting baud rate. The work also includes an application for simulation of transmission speed as a function of distance for G.fast and G.mgfast technologies, allowing changing input parameters and adjusting the transmission bandwidth based on G.9700 and G.9701 standards. Also, in work, an application is created to display the compensation of the influence of the transmitted signal crosstalk FEXT and NEXT, which allow the import of measured crosstalk between individual participants. The issue of influencing crosstalk for accurate measurements in the laboratory is also discussing. An application in the MATLAB environment is creating to display the measured characteristics.
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Parent, Marc-Antoine. "Third generation mobile communications : capacity of a time-division duplex code-division multiple access cellular system." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=29543.

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This thesis describes the work done in evaluating the capacity of a multi-service third generation (3G) wireless communication system based on the Universal Mobile Telecommunication System (UNITS). More specifically, the study presented in these pages examines the Time Division Duplex (TDD) paradigm supported by the 3G Partnership Project (3GPP).
The goal is to establish the probability that a new connection attempt be successful as a function of the instantaneous load on the network. The sought capacity is evaluated with the help of an analytical model and a simulation tool. Both tools used a so-called system-level approach. The model and the simulator were developed based on 3GPP's standard and available data from link-level simulations.
Some of the significant results presented are: (1) A maximum of around 7 to 9 orthogonal codes can be used per timeslot. (2) A UMTS TDD CDMA system should be used in pico- and micro-cellular environments in order to support efficient data transmissions. (3) The multicode interference is often wrongfully neglected in capacity studies. (4) Capacity is downlink interference-limited, even with a modest MUD efficiency.
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Foutekova, Ellina P. "Interference mitigation and interference avoidance for cellular OFDMA-TDD networks." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/3810.

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In recent years, cellular systems based on orthogonal frequency division multiple access – time division duplex (OFDMA-TDD) have gained considerable popularity. Two of the major reasons for this are, on the one hand, that OFDMA enables the receiver to effectively cope with multipath propagation while keeping the complexity low. On the other hand, TDD offers efficient support for cell-specific uplink (UL)/downlink (DL) asymmetry demands by allowing each cell to independently set its UL/DL switching point (SP). However, cell-independent SP gives rise to crossed slots. In particular, crossed slots arise when neighbouring cells use the same slot in opposing link directions, resulting in base station (BS)-to-BS interference and mobile station (MS)-to-MS interference. BS-to-BS interference, in particular, can be quite detrimental due to the exposed location of BSs, which leads to high probability of line-of-sight (LOS) conditions. The aim of this thesis is to address the BS-to-BS interference problem in OFDMA-TDDcellular networks. A simulation-based approach is used to demonstrate the severity of BS-to-BS interference and a signal-to-interference-plus-noise ratio (SINR) equation for OFDMA is formulated to aid system performance analysis. The detrimental effects of crossed slot interference in OFDMA-TDD cellular networks are highlighted by comparing methods specifically targeting the crossed slots interference problem. In particular, the interference avoidance method fixed slot allocation (FSA) is compared against state of the art interference mitigation approaches, viz: random time slot opposing (RTSO) and zone division (ZD). The comparison is done based on Monte Carlo simulations and the main comparison metric is spectral efficiency calculated using the SINR equation formulated in this thesis. The simulation results demonstrate that when LOS conditions among BSs are present, both RTSO and ZD perform worse than FSA for all considered performance metrics. It is concluded from the results that current interference mitigation techniques do not offer an effective solution to the BS-to-BS interference problem. Hence, new interference avoidance methods, which unlike FSA, do not sacrifice the advantages of TDD are open research issues addressed in this thesis. The major contribution of this thesis is a novel cooperative resource balancing technique that offers a solution to the crossed slot problem. The novel concept, termed asymmetry balancing, is targeted towards next-generation cellular systems, envisaged to have ad hoc and multi-hop capabilities. Asymmetry balancing completely avoids crossed slots by keeping the TDD SPs synchronised among BSs. At the same time, the advantages of TDD are retained, which is enabled by introducing cooperation among the entities in the network. If a cell faces resource shortage in one link direction, while having free resources in the opposite link direction, the free resources can be used to support the overloaded link direction. In particular, traffic can be offloaded to near-by mobile stations at neighbouring cells that have available resources. To model the gains attained with asymmetry balancing, a mathematical framework is developed which is verified by Monte Carlo simulations. In addition, asymmetry balancing is compared against both ZD and FSA based on simulations and the results demonstrate the superior performance of asymmetry balancing. It can be concluded that the novel interference avoidance approach is a very promising candidate to.
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Mori, Kazuo, Takehiko Kobayashi, Takaya Yamazato, and Akira Ogawa. "Transmission Power Control for Downlinks in CDMA/Shared-TDD Cellular Packet Systems." IEEE, 2000. http://hdl.handle.net/2237/7805.

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Sklikas, Pavlos. "Downlink/uplink timing synchronisation for 4th generation time division duplex mobile networks using radio-over-fibre." Thesis, University of Kent, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.595828.

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Radio over Fibre (RoF) Distributed Antenna Systems can be deployed in combination with pre-4G and 4G technologies, proposed by the IEEE 802.16 and 3GPP LTE standards, in order to support the increased demand for capacity and coverage for various outdoor, inbuilding and underground scenarios. However, the Physical and Medium Access Control (MAC) protocols have not been designed to account for the additional propagation delay that the optical distribution network inserts. This thesis presents a detailed theoretical analysis of protocol effects in Time Division Duplex (TOO) IEEE 802.16 and 3GPP LTE RoF networks, supported by mathematical analyses. The round trip delays and the timing boundaries of the wireless technologies under investigation might be affected when the optical propagation delay is not taken into account. The analysis indicates that the default durations of the TransmitIReceive Transition Gap (TTG) and the Guard Period, which allow for the downlink-uplink timing synchronisation between the Base Station (BS)Evolved Node B (eNB) and the users, can accommodate fibre lengths up to 14.4 km, 27 km and 69.7 km for legacy IEEE 802.16, IEEE 802.16m and 3GPP TD-LTE systems, respectively. Also, the initial Ranging (IR) slot and the Physical Random Access Channel duration, used for the estimation of the user's distance from the BS/eNE, can accommodate fibre lengths up to 13.2 km, 93 km and 69 Ian for legacy IEEE 802.16, IEEE 802.16m and 3GPP TD-LTE systems, respectively. Furthennore, the OFDM symbol's CP duration has to be chosen based on the maximum difference in fibre lengths between the Remote Antenna Units that needs to be supported in the RoF network. The maximum fibre length differences allowed by the default CP in legacy IEEE 802.16, IEEE 802.l6m and 3GPP TD-LTE systems are equal to 2.2 km, 2.2 km and 1.15 km, respectively. However, it is shown that the system perfonnance deteriorates when these parameters are adapted in order to accommodate longer optical propagation delays and greater fibre length differences. The required protocol and parameter changes for the alleviation of the limitation imposed on the maximum fibre link length are presented. The proposed solutions concern the IR procedure and the MAC management Medium Access Protocol (MAP) messages' timing relevance. The optical propagation delay is compensated and the downlink-uplink timing synchronization between the as and the users is maintained. Thus, the wireless propagation delay estimation (ranging) is successfully carried out, even when the optical propagation delay is greater than what the IR slot and/or the TTG duration can accommodate, and the system's performance is improved, without the need of increased overhead.
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Rachad, Jalal. "TDD based 5G networks performance analysis and radio resource dimensioning with different network geometry models." Electronic Thesis or Diss., Institut polytechnique de Paris, 2019. http://www.theses.fr/2019IPPAT008.

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Une nouvelle génération des réseaux mobiles, connue sous le nom de 5G NR, est en cours de standardisation à travers des améliorations apportées à son prédécesseur 4G/4G+. 5G NR va introduire un nouveau niveau de flexibilité, scalabilité et efficacité afin de satisfaire plusieurs classes de services. Le mode de duplexage TDD est le plus favorable pour 5G NR grâce aux avantages qu’il représente par rapport au mode FDD en termes de capacité, flexibilité et convenance de déploiement avec les autres technologies attendues dans le cadre de la 5G comme FD-MIMO. Une variante du TDD, connue sous le nom du dynamique TDD (D-TDD), attire de plus en plus l’attention. D-TDD est désigné pour l’adaptation des configurations des sous-trames DL et UL en se basant sur une estimation instantanée du trafic. Cependant, l’utilisation de ce mode nécessite l’implémentation des mécanismes capable de réduire deux types d’interférence additionnelles : l’interférence générée par les stations de bases qui impacte le signal UL des utilisateurs et l’interférence générée par les mobiles en UL qui interfère avec le signal DL des stations de base. La première partie de cette thèse est consacrée à l’analyse des performances du mode D-TDD en termes de ISR et de la probabilité de couvertures dans 2 types de déploiement : macro-cells et small-cells. Ensuite, nous proposons deux techniques de mitigation des interférences dont la première est destinée aux macro-cells et basée sur le 3D beamforming tandis que la 2ème est le cell clustering et appliquée au small-cells. Dans la 2ème partie de cette thèse, nous étudions la problématique du dimensionnement de l’OFDMA qui sera une technologie de base pour la 5G NR. Etant donné que le dimensionnement des ressources radio est une tâche primordiale dans l’ingénierie radio, nous proposons un modèle analytique qui permet la réalisation de cette tâche en considérant un scheduling proportional fair. Nous distinguons entre 2 types d’utilisateurs : utilisateurs indoor qui sont modélisés par un PPP spatial et utilisateurs outdoor qui sont modélisés selon un processus de Cox conduit par un PLP. Plusieurs résultats analytiques et numériques sont exposés afin de justifier l’exactitude et la précision de ce modèle
A new generation of cellular networks, known as 5G new radio (NR), has been standardized through improvements in the current 4G/4G+ concepts and features in order to bring a new level of flexibility, scalability and efficiency. Time division duplex (TDD) is expected to be one of the key features of 5G NR since it offers more advantages than frequency division duplex (FDD) mode in terms of capacity, flexibility and implementation adequacy with other features, such as full dimension multiple input multiple output antenna (FD-MIMO) technology. A variant operational mode of TDD, known as D-TDD, is in the scope. It is designed to deal with uplink (UL) and downlink (DL) traffic asymmetry since it is based on instantaneous traffic estimation and offers more flexibility in resource assignment. However, the use of D-TDD requires new interference mitigation schemes capable to handle two additional types of interference called cross link interference (CLI) and stands for DL to UL and UL to DL interference. The first part of this thesis is devoted to tackle the problem of interference modeling in D-TDD based macro-cell and small-cell deployments. We provide a complete analytical approach to derive relevant metrics, such as interference-to-signal-ratio (ISR) and the coverage probability formulas, considering adequate geometry models for each type of deployment. Then, we propose an interference mitigation scheme based on 3D beamforming for macro-cells and a cell-clustering scheme for small-cells. Additionally, we investigate another problematic which is Orthogonal Frequency Division Multiplex (OFDM) radio resource dimensioning. Since 5G NR takes in consideration a wide array of emerging use cases and also the possibility of having future requirements, the third Generation Partnership Project (3GPP) comes up with a variant of OFDM known as scalable OFDM and having different sub carriers' spacing. This feature appears to be an ideal choice for 5G NR since it offers a high spectral efficiency, robustness to selective fading channels, convenience with diverse spectrum bands and compatibility with other features. Therefore, dimensioning OFDM is a major task to accomplish in the context of NR. To this purpose, we provide an analytical model to dimension OFDM based systems with a proportional fair resources' allocation policy. We model indoor users by a spatial PPP and outdoor users according to a Cox process driven by PLP. Different analytical and numerical results are provided to justify the accuracy of this model
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Al-Saadeh, Osama. "Performance of In-Band Full-Duplex for 5G Wireless Networks." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-199943.

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In-band full duplex is a new duplexing scheme that allows radio nodes to transmit and receive, utilizing the same frequency and time resources. The implementation of in-band full duplex was not feasible in practice, due to the effect of self-interference. But then, advances in signal processing made it possible to reduce this effect. However, the system level performance of in-band full duplex has not been investigated thoroughly.Through computer simulations, we investigate the performance of in-band full duplex, for indoor 5G small cell wireless networks. We examine the performance of in-band full duplex in comparison to dynamic and static time division duplexing. Additionally, we analyze the performance of the duplexing schemes with two interference mitigation techniques, namely beamforming and interference cancellation.Our results indicate that for highly utilized wireless networks, in-band full duplex should be combined with beamforming and interference cancellation, in order to achieve a performance gain over traditional duplexing schemes. Only then, in-band full duplex is considered advantageous, at any network utilization, and any downlink to uplink traffic demand proportion. Our results also suggest that in order to achieve a performance gain with in-band full duplex in both links, the transmit power of the access points should be comparable to the transmit power of the mobile stations.
Inomband hel duplex är en ny typ av duplexmetod som tillåter radionoder att sända och ta emot i samma frekvensoch tidsresurs. Att implementera inomband hel duplex har fram tills nu inte ansetts praktiskt genomförbart till följd av självstörningar. Framsteg inom signalbehandling har dock gjort det möjligt att begränsa denna självstörningseffekt. Emellertid har systemprestanda av inomband hel duplex inte undersökts tillräckligt noga i tidigare verk.Inomband hel duplex och dess prestanda för trådlösa 5G småcellsnätverk inomhus har studerats med hjälp av datasimuleringar och jämförts med dynamisk och statisk tidsdelning. Utöver detta har prestanda för de olika duplexmetoderna med avseende på två tekniker för störningsundertryckning, lobformning och störningseliminering, också undersökts.Våra resultat indikerar att för trådlösa nätverk med högt radioresursutnyttjande bör inomband hel duplex kombineras med lobformning och störningseliminering för att uppnå en prestandavinst jämfört med traditionella duplexmetoder. Bara då kan inomband hel duplex anses vara fördelaktig oberoende av radioresursutnyttjande och andelen upp- och nedlänkstrafik.Resultaten tyder också på att sändareffekten för radioaccesspunkterna bör vara jamförbar med den för mobilenheterna för att en prestandavinst med inomband hel duplex ska kunna uppnås.
Wireless networks, In-band full duplex, Static-time division duplexing, Dynamic-time division duplexing, Interference mitigation techniques, small cell, 5G, mmWave bands, Beamforming, Interference cancellation.
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Savoine, M?rcia Maria. "An?lise da efici?ncia espectral considerando a duplexa??o e o perfil de tr?fego para bandas licenciadas." Pontif?cia Universidade Cat?lica de Campinas, 2009. http://tede.bibliotecadigital.puc-campinas.edu.br:8080/jspui/handle/tede/504.

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This work presents the comparison made through simulations of discreet events, accomplished with the software ARENA, the techniques of Time Division Duplex (TDD) and Frequency Division Duplex (FDD). Techniques present in the pattern IEEE 802.16 and used by WiMAX in the bi-directional channels of uplink and downlink. The simulation model considered in the line of arrival of the services the concept FIFO (First-In, First-Out) and the simulations were accomplished considering five applications (Streaming, Download, Web, E-mail and Small-Transaction) for downlink and uplink. The number of channels in the Base Station varied from 4 to 60, with a throughput of 600 kbps. The regarded efficiency parameter was the minimum number of channels necessary in each one of the standard channels. The simulations were accomplished in three sceneries., In the first scenery it was considered the same profile of traffic for downlink and uplink, in the second scenery a traffic of downlink 2, 5, 10 and 15 times larger than the one of uplink. And, in the third scenery it was considered different proportions of traffics varying from 2 to 5 times more, 5 to 10 times more and from 10 to 15 times more. The analyses were done considering as efficiency parameter the converge of the waiting time of the users. ,It was verified that in asymmetric data traffic, the TDD technique was more efficient and there were spectrum idleness in the FDD technique.
Este trabalho apresenta a compara??o efetuada por meio de simula??es de eventos discretos, realizadas com o software ARENA, das t?cnicas de Duplexa??o por Divis?o no Tempo (TDD) e Duplexa??o por Divis?o da Freq??ncia (FDD), t?cnicas presentes no padr?o IEEE 802.16 e utilizadas pelo WiMAX nos canais bidirecionais de uplink e downlink. O modelo de simula??o considerou na fila de chegada dos servi?os o conceito FIFO (First-In, First-Out) e as simula??es foram realizadas considerando cinco aplica??es (Streaming, Download, Web, E-mail e Small-Transaction) para downlink e uplink. O n?mero de canais na Base Station variou de 4 a 60, com um throughput de 600 kbps. O par?metro de efici?ncia considerado foi o n?mero m?nimo de canais necess?rio em cada um dos canais padr?es. As simula??es foram realizadas em tr?s cen?rios, sendo que, no primeiro cen?rio se considerou o mesmo perfil de tr?fego para downlink e uplink, no segundo cen?rio com tr?fego de downlink 2, 5, 10 e 15 vezes maior que o de uplink. E, no terceiro cen?rio com propor??es variadas de tr?fegos variando de 2 a 5 vezes mais, 5 a 10 vezes mais e de 10 a 15 vezes mais. Realizadas as simula??es foram feitas as an?lises dos desempenhos, tomando como par?metro de efici?ncia a taxa de chegada e o tempo de espera do usu?rio perante aplica??es t?picas utilizadas na tecnologia de banda licenciada WiMAX, que segue este padr?o. A an?lise efetuada permitiu identificar, dada estas condi??es de tr?fego, qual das t?cnicas seria a mais indicada. Constatou-se ainda que em tr?fego de dados assim?tricos a t?cnica TDD se apresentou mais eficiente e, observou-se existir ociosidade de espectro na t?cnica FDD.
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Book chapters on the topic "Time division duplex TDD"

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Nakagawa, Masao, and Riaz Esmailzadeh. "Time Division Duplex-CDMA." In Multi-Carrier Spread-Spectrum & Related Topics, 13–21. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/978-1-4757-3569-7_2.

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Cosovic, Ivan, Michael Schnell, and Andreas Springer. "Combined Pre- and Post-Equalization for Uplink Time Division Duplex MC-CDMA in Fading Channels." In Multi-Carrier Spread-Spectrum, 439–50. Dordrecht: Springer Netherlands, 2004. http://dx.doi.org/10.1007/978-94-017-0502-8_50.

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Anisimov, V. G., V. N. Perelomov, L. O. Myrova, and D. A. Aminev. "Analysis of the Possibilities of Using the Means of Tropospheric cm-Wave Radio Communication with a Time Division Duplex in Telecommunication Systems." In Developments in Language Theory, 514–24. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-99447-5_44.

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Li, Qinghua, Xintian Eddie Lin, and Jianzhong ("Charlie") Zhang. "MIMO Beamforming." In Handbook on Advancements in Smart Antenna Technologies for Wireless Networks, 240–63. IGI Global, 2009. http://dx.doi.org/10.4018/978-1-59904-988-5.ch012.

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Transmit beamforming improves the performance of multiple-input multiple-output antenna system (MIMO) by exploiting channel state information (CSI) at the transmitter. Numerous MIMO beamforming schemes are proposed in open literature and standard bodies such as 3GPP, IEEE 802.11n and 802.16d/e. This chapter describes the underlying principle, evolving techniques, and corresponding industrial applications of MIMO beamforming. The main limiting factor is the cumbersome overhead to acquire CSI at the transmitter. The solutions are categorized into FDD (Frequency Division Duplex) and TDD (Time Division Duplex) approaches. For all FDD channels and radio calibration absent TDD channels, channel reciprocity is not available and explicit feedback is required. Codebook-based feedback techniques with various quantization complexities and feedback overheads are depicted in this chapter. Furthermore, we discuss transmit/receive (Tx/Rx) radio chain calibration and channel sounding techniques for TDD channels, and show how to achieve channel reciprocity by overcoming the Tx/Rx asymmetry of the RF components
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Dvorkin, Vladimir. "Fast time division duplex (TDD) transmission using an upconverting mixer with a high side switch." In Analog Circuit Design, 1063–64. Elsevier, 2015. http://dx.doi.org/10.1016/b978-0-12-800001-4.00493-2.

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Conference papers on the topic "Time division duplex TDD"

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Qaddus, Ahmed, Aamir Ali Raza, and Ali Mustafa. "Deploying uninterrupted wireless communication networks by using Software Define Cognitive Radios (SDCR) and Time Division Duplex (TDD) transmission techniques in 5G networks." In 2015 International Conference on Information and Communication Technologies (ICICT). IEEE, 2015. http://dx.doi.org/10.1109/icict.2015.7469586.

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Dinh-Thuy Phan-Huy, Slim Ben Halima, and M. Helard. "Frequency Division Duplex Time Reversal." In 2011 IEEE Global Communications Conference (GLOBECOM 2011). IEEE, 2011. http://dx.doi.org/10.1109/glocom.2011.6133557.

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Tian, Lan, Jianhao Hu, and Xingzhong Xiong. "A Time Reversal Based Time Division Duplex IDMA Communication System." In 2007 International Conference on Future Generation Communication and Networking. IEEE, 2007. http://dx.doi.org/10.1109/fgcn.2007.47.

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Bin Ali, Shahrukh, Chia-Hao Yu, Olav Tirkkonen, and Cassio Ribeiro. "Optimization of Dynamic Frame Offset in Time Division Duplex System." In 2011 IEEE Vehicular Technology Conference (VTC 2011-Spring). IEEE, 2011. http://dx.doi.org/10.1109/vetecs.2011.5956597.

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Park, Daegeun, Youngil Kim, Yongtae Lee, and Won Ryu. "Implementation of mobile relay system for supporting adjustable time division duplex." In 2014 International Conference on Information and Communication Technology Convergence (ICTC). IEEE, 2014. http://dx.doi.org/10.1109/ictc.2014.6983244.

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Liu, Y. F., C. W. Chow, and C. H. Yeh. "Time division duplex for preventing reflection interference in visible light communication." In 2012 21st Annual Wireless and Optical Communications Conference (WOCC 2012). IEEE, 2012. http://dx.doi.org/10.1109/wocc.2012.6198178.

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Adachi, Fumiyuki, Amnart Boonkajay, Yuta Seki, and Tomoyuki Saito. "MIMO channel estimation for time-division duplex distributed antenna cooperative transmission." In 2017 13th International Wireless Communications and Mobile Computing Conference (IWCMC). IEEE, 2017. http://dx.doi.org/10.1109/iwcmc.2017.7986288.

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Liu, Ye, Sangarapillai Lambotharan, Arumugam Nallanathan, and Kai-Kit Wong. "Pricing based interference control in reversed time division duplex heterogeneous networks." In ICC 2016 - 2016 IEEE International Conference on Communications. IEEE, 2016. http://dx.doi.org/10.1109/icc.2016.7510740.

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Kim, Young An, and Choong Seon Hong. "Coherent Detection Method with Compensation at Transmitter in Time Division Duplex System." In 2007 International Conference on Multimedia and Ubiquitous Engineering (MUE'07). IEEE, 2007. http://dx.doi.org/10.1109/mue.2007.104.

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Jungnickel, V., U. Kruger, G. Istoc, T. Haustein, and C. von Helmolt. "A MIMO system with reciprocal transceivers for the time-division duplex mode." In IEEE Antennas and Propagation Society Symposium, 2004. IEEE, 2004. http://dx.doi.org/10.1109/aps.2004.1330415.

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