Relevant bibliographies by topics / Uplink channel

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Uplink channel'

Author: Grafiati
Published: 4 June 2025
Last updated: 15 July 2025

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Uplink channel.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Uplink channel"

1

Cho, Sunghyun, Ji-Su Kim, and Jae-Hyun Kim. "Enhanced Handoff Scheme for Downlink-Uplink Asymmetric Channels in Cellular Systems." Scientific World Journal 2013 (2013): 1–12. http://dx.doi.org/10.1155/2013/241483.

Full text
Abstract:
In the latest cellular networks, data services like SNS and UCC can create asymmetric packet generation rates over the downlink and uplink channels. This asymmetry can lead to a downlink-uplink asymmetric channel condition being experienced by cell edge users. This paper proposes a handoff scheme to cope effectively with downlink-uplink asymmetric channels. The proposed handoff scheme exploits the uplink channel quality as well as the downlink channel quality to determine the appropriate timing and direction of handoff. We first introduce downlink and uplink channel models that consider the intercell interference, to verify the downlink-uplink channel asymmetry. Based on these results, we propose an enhanced handoff scheme that exploits both the uplink and downlink channel qualities to reduce the handoff-call dropping probability and the service interruption time. The simulation results show that the proposed handoff scheme reduces the handoff-call dropping probability about 30% and increases the satisfaction of the service interruption time requirement about 7% under high-offered load, compared to conventional mobile-assisted handoff. Especially, the proposed handoff scheme is more efficient when the uplink QoS requirement is much stricter than the downlink QoS requirement or uplink channel quality is worse than downlink channel quality.
APA, Harvard, Vancouver, ISO, and other styles
2

Fan, Wei, Pekka Kyösti, Jesper Ø. Nielsen, Lassi Hentilä, and Gert F. Pedersen. "Emulating Realistic Bidirectional Spatial Channels for MIMO OTA Testing." International Journal of Antennas and Propagation 2015 (2015): 1–13. http://dx.doi.org/10.1155/2015/289843.

Full text
Abstract:
This paper discusses over the air (OTA) testing for multiple input multiple output (MIMO) capable terminals with emphasis on modeling bidirectional spatial channel models in multiprobe anechoic chamber (MPAC) setups. In the literature, work on this topic has been mainly focused on how to emulate downlink channel models, whereas uplink channel is often modeled as free space line-of-sight channel without fading. Modeling realistic bidirectional (i.e., both uplink and downlink) propagation environments is essential to evaluate any bidirectional communication systems. There have been works stressing the importance of emulating full bidirectional channel and proposing possible directions to implement uplink channels in the literature. Nevertheless, there is no currently published work reporting an experimental validation of such concepts. In this paper, a general framework to emulate bidirectional channels for time division duplexing (TDD) and frequency division duplexing (FDD) communication systems is proposed. The proposed technique works for MPAC setups with arbitrary uplink and downlink probe configurations, that is, possibly different probe configurations (e.g., number of probes or their configurations) in the uplink and downlink. The simulation results are further supported by measurements in a practical MPAC setup. The proposed algorithm is shown to be a valid method to emulate bidirectional spatial channel models.
APA, Harvard, Vancouver, ISO, and other styles
3

Liu, Qingli, Jiaxu Sun, and Peiling Wang. "Uplink Assisted MIMO Channel Feedback Method Based on Deep Learning." Entropy 25, no. 8 (2023): 1131. http://dx.doi.org/10.3390/e25081131.

Full text
Abstract:
In order to solve the problem wherein too many base station antennas are deployed in a massive multiple-input–multiple-output system, resulting in high overhead for downlink channel state information feedback, this paper proposes an uplink-assisted channel feedback method based on deep learning. The method applies the reciprocity of the uplink and downlink, uses uplink channel state information in the base station to help users give feedback on unknown downlink information, and compresses and restores the channel state information. First, an encoder–decoder structure is established. The encoder reduces the network depth and uses multi-resolution convolution to increase the accuracy of channel state information extraction while reducing the number of computations relating to user equipment. Afterward, the channel state information is compressed to reduce feedback overhead in the channel. At the decoder, with the help of the reciprocity of the uplink and downlink, the feature extraction of the uplink’s magnitudes is carried out, and the downlink channel state information is integrated into a channel state information feature matrix, which is restored to its original size. The simulation results show that compared with CSINet, CRNet, CLNet, and DCRNet, indoor reconstruction precision was improved by an average of 16.4%, and outside reconstruction accuracy was improved by an average of 21.2% under all compressions.
APA, Harvard, Vancouver, ISO, and other styles
4

Mengesha, Befekadu, Pablo Torres-Ferrera, and Roberto Gaudino. "Analysis of 5G New Radio Uplink Signals on an Analogue-RoF System Based on DSP-Assisted Channel Aggregation." Applied Sciences 9, no. 1 (2018): 47. http://dx.doi.org/10.3390/app9010047.

Full text
Abstract:
The 3rd Generation Partnership Project (3GPP) is in the process of developing 5th generation (5G) radio access technology, the so-called new radio (NR). The aim is to achieve the performance requirements forIMT-2020 radio interface technology. In this paper, we focus on the analysis of the transmission of 5G NR uplink physical channels, such as physical uplink shared channel (PUSCH) and physical uplink control channel (PUCCH), dedicated for data and control channels, respectively, as specified in the 3GPP standard, using digital signal processing (DSP)-assisted frequency division multiple access (FDMA) and time division multiple access (TDMA) channel aggregation techniques on an analogue radio-over-fiber (A-RoF) architecture. We verified that there is ~34% spectral efficiency gain and lower error vector magnitude (EVM) achieved using the TDMA technique.
APA, Harvard, Vancouver, ISO, and other styles
5

Oyerinde, Olutayo Oyeyemi, Adam Flizikowski, Tomasz Marciniak, Dmitry Zelenchuk, and Telex Magloire Nkouatchah Ngatched. "Compressive Sensing-Based Channel Estimation for Uplink and Downlink Reconfigurable Intelligent Surface-Aided Millimeter Wave Massive MIMO Systems." Electronics 13, no. 15 (2024): 2909. http://dx.doi.org/10.3390/electronics13152909.

Full text
Abstract:
This paper investigates single-user uplink and two-user downlink channel estimation in reconfigurable intelligent surface (RIS)-aided millimeter-wave (mmWave) massive multiple-input multiple-output (MIMO) wireless communication systems. Because of the difficulty associated with the estimation of channels in RIS-aided wireless communication systems, channel state information (CSI) is assumed to be known at the receiver in some previous works in the literature. By assuming that prior knowledge of the line-of-sight (LoS) channel between the RIS and the base station (BS) is known, two compressive sensing-based channel estimation schemes that are based on simultaneous orthogonal matching pursuit and structured matching pursuit (StrMP) algorithms are proposed for estimation of uplink channel between RIS and user equipment (UE), and joint estimations of downlink channels between BS and a UE, and between RIS and another UE, respectively. The proposed channel estimation schemes exploit the inherent common sparsity shared by the angular domain mmWave channels at different subcarriers. The superiority of one of the proposed channel estimation techniques, the StrMP-based channel estimation technique, with negligibly higher computational complexity cost compared with other channel estimators, is documented through extensive computer simulation. Specifically, with a reduced pilot overhead, the proposed StrMP-based channel estimation scheme exhibits better performance than other channel estimation schemes considered in this paper for signal-to-noise ratio (SNR) between 0 dB and 5 dB upward at different instances for both uplink and downlink scenarios, respectively. However, below these values of SNR the proposed StrMP-based channel estimation scheme will require higher pilot overhead to perform optimally.
APA, Harvard, Vancouver, ISO, and other styles
6

Rim, Minjoong, and Chung Kang. "Uplink Non-Orthogonal Multiple Access with Channel Estimation Errors for Internet of Things Applications." Sensors 19, no. 4 (2019): 912. http://dx.doi.org/10.3390/s19040912.

Full text
Abstract:
One of the key requirements for next generation wireless or cellular communication systems is to efficiently support a large number of connections for Internet of Things (IoT) applications, and uplink non-orthogonal multiple access (NOMA) schemes can be used for this purpose. In uplink NOMA systems, pilot symbols, as well as data symbols can be superimposed onto shared resources. The error rate performance can be severely degraded due to channel estimation errors, especially when the number of superimposed packets is large. In this paper, we discuss uplink NOMA schemes with channel estimation errors, assuming that quadrature phase shift keying (QPSK) modulation is used. When pilot signals are superimposed onto the shared resources and a large number of devices perform random accesses concurrently to a single resource of the base station, the channels might not be accurately estimated even in high SNR environments. In this paper, we propose an uplink NOMA scheme, which can alleviate the performance degradation due to channel estimation errors.
APA, Harvard, Vancouver, ISO, and other styles
7

Zhangyong, Li. "Millimeter Wave Multi-mode OAM-MIMO Channel Capacity Study." Journal of Big Data and Computing 2, no. 2 (2024): 35–45. http://dx.doi.org/10.62517/jbdc.202401206.

Full text
Abstract:
This study examines the theoretical aspects of channel capacity for millimeter wave multi-mode Orbital Angular Momentum (OAM) Multiple Input Multiple Output (MIMO) systems. It begins with a theoretical analysis of these channels, highlighting their importance and potential applications in wireless communications. A Sparse Bayesian Learning (SBL) based Joint Uplink and Downlink Channel Estimation (JUDCE) approach is then employed to estimate the downlink channel using uplink training signals, while accounting for inactive receiving antennas. Exploiting the sparsity of millimeter wave channels, the downlink channel estimation is modeled as a compressed sensing problem using a binary mask matrix. An SBL framework is developed to efficiently tackle this problem. Theoretical and simulation results indicate the proposed method significantly improves channel estimation accuracy and spectral efficiency of downlink transmissions, underscoring its importance for the advancement of future communication technologies.
APA, Harvard, Vancouver, ISO, and other styles
8

Zhao, Bai-Shan, Peng-Fei Lv, and Yan-Qing Hong. "Channel Correlation-Based Adaptive Power Transmission for Free-Space Optical Communications." Photonics 11, no. 9 (2024): 859. http://dx.doi.org/10.3390/photonics11090859.

Full text
Abstract:
Free-space optical (FSO) communication has received widespread attention as a high-bandwidth, low-latency communication technique. However, the scintillation effect caused by atmospheric turbulence leads to intensity fluctuations of the transmission signal, which, in turn, affects the performance of the FSO communication system. This paper proposes a channel correlation-based adaptive power transmission for FSO communications. Based on the correlation between uplink and downlink turbulence channels, the power of the reverse transmission signal is adjusted by the fluctuation strength of the received uplink or downlink transmission signal and the channel correlation coefficient to improve the system’s performance. The proposed technique is investigated through a simulation using established uplink and downlink channels with different link distances and turbulence intensities. The simulation results show that the bit error rate (BER) performance of the proposed technique is significantly improved compared to the fixed threshold decision (FTD) technique, and it is close to the adaptive threshold decision (ATD) technique. The proposed technique provides an effective optimization scheme for FSO communications.
APA, Harvard, Vancouver, ISO, and other styles
9

Yalavarthy, Srinivasa Rao. "Optimizing Uplink Scheduling in IEEE 802.11bn UHR Networks with NPCA Primary Channel Access." European Journal of Computer Science and Information Technology 13, no. 49 (2025): 117–30. https://doi.org/10.37745/ejcsit.2013/vol13n49117130.

Full text
Abstract:
This article explores uplink scheduling optimization in IEEE 802.11bn Ultra High Reliability (UHR) networks utilizing Non-Primary Channel Access (NPCA) functionality. NPCA enhances network resilience by enabling devices to switch to alternative channels when the primary channel experiences congestion, but introduces challenges in uplink scheduling efficiency and fairness. Traditional Enhanced Distributed Channel Access (EDCA) mechanisms prove inadequate in time-constrained NPCA scenarios due to collision probability and fairness concerns. The proposed solution implements a trigger-based uplink optimization approach through carefully configured Multi-user EDCA parameters. By setting Arbitration Interframe Space values to zero for all Access Categories and implementing maximum MU-EDCA timer values with timer reset mechanisms, the approach shifts from distributed contention to centralized AP-controlled scheduling. This comprehensive architecture delivers multiple technical benefits: enhanced fairness through sophisticated scheduling algorithms, collision elimination through coordinated access, reduced overhead through parameter optimization, and extended control windows through timer management. The trigger-based approach transforms NPCA operation into a highly efficient, predictable communication channel suitable for applications with strict quality of service requirements in interference-prone environments.
APA, Harvard, Vancouver, ISO, and other styles
10

Syed Ameer Abbas, S., M. Venisubha, S. Siva Gayathri, and S. J. Thiruvengadam. "Realization of LTE physical layer baseband processing architecture for narrowband IOT." International Journal of Engineering & Technology 7, no. 2.31 (2018): 56. http://dx.doi.org/10.14419/ijet.v7i2.31.13397.

Full text
Abstract:
The 3GPP Long Term Evolution represents the major innovation in cellular technology. NB-IoT is the 3GPP standard for machine to machine communication finalized within LTE Release13. NB-IoT technology occupies frequency band of 180 kHz bandwidth which corresponds to one resource block in LTE transmission. The Long Term Evolution (LTE) supports higher data rates, higher bandwidth, Low latency, good Quality of Service whereas objective of Narrow Band Internet of Things (NB - IOT) is to achieve extended coverage, to support massive number of smart devices and have multi - year long battery life. So the main focus is linking LTE with IOT. The objective of this paper proposes transmitter architecture of PUCCH (Physical Uplink Control Channel) and PUSCH(Physical uplink Shared Channel) in SISO and SIMO configurations for physical uplink channels of LTE. The physical uplink and downlink channel processing involves scrambling, modulation, layer mapping, transform precoding, and resource element mapping at the transmitter and the receiver block to have demapping from the resource elements and detection of data. At present, the data for on-off control has been worked and the whole framework has been simulated using Modelsim and implemented in Spartan 6.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Uplink channel"

1

Ho, Kenneth T. "Uplink channel estimation in WiMAX." College Park, Md. : University of Maryland, 2008. http://hdl.handle.net/1903/8214.

Full text
Abstract:
Thesis (M.S.) -- University of Maryland, College Park, 2008.<br>Thesis research directed by: Dept. of Electrical and Computer Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
APA, Harvard, Vancouver, ISO, and other styles
2

Ahmed, Mohsin Niaz. "LTE Uplink Modeling and Channel Estimation." Thesis, Linköpings universitet, Datorteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-69571.

Full text
Abstract:
This master thesis investigates the uplink transmition from User Equipment (UE) to base station in LET (Long Term Evolution) and channel estimation using pilot symbols with parameter defined in 3GPP (3rd Generation Partnership Project) specifications. The purpose of the thesis was to implement a simulator which can generate uplink signal as it is generated by UE. The Third Generation (3G) mobile system was given the name LTE. This thesis focus on the uplink of LTE where single carrier frequency division multiple access (SC-FDMA) is utilized as a multiple access technique. The advantage over the orthogonal frequency division multiple access (OFDMA), which is used in downlink is to get better peak power characteristics. Because in uplink communication better peak power characteristic is necessary for better power efficiency in mobile terminals. To access the performance of uplink transmition realistic channel model for wireless communication system is essential. Channel models used are proposed by International Telecommunication Union (ITU) and the correct knowledge of these models is important for testing, optimization and performance improvements of signal processing algorithms. The channel estimation techniques used are Least Square (LS) and Least Minimum Mean Square Error (LMMSE) for different channel models. Performance of these algorithms has been measured in term of Bit Error Rate (BER) and Signal to Noise Ratio (SNR).
APA, Harvard, Vancouver, ISO, and other styles
3

Lindén, Erik. "Iterative Channel Estimation in LTE Uplink." Thesis, KTH, Kommunikationsteori, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-147128.

Full text
Abstract:
An algorithm for iterative channel estimation using soft feedback for LTE uplink is proposed. The algorithm has low complexity compared to MMSE estimation and does not require knowledge of the channel statistics. A simple polynomial model is used for noise suppression across OFDM symbols and a DCT-based filter is used for noise suppression across subcarriers. The algorithm has been tested on several channel models and has been shown to provide a gain of about 0:5 dB with two estimation stages, compared to the no-feedback case. Further, the algorithm has been applied to a MIMO case. A comparison has been made between the proposed algorithm and turbo equalization.<br>En algoritm for iterativ kanalestimering i LTE-upplank foreslas. Algoritmen harlag komplexitet jamfort med MMSE-estimering. En enkel polynomiell modellanvands for att undertrycka brus over OFDM-symboler och ett DCT-baseratlter anvands for att undertrycka brus over sub-barvagor.Algoritmen har testats med era kanalmodeller och visats ge en vinst pa cirka0:5 dB med tva estimeringsitrationer, jamfort med en icke-iterativ mottagare.Algoritmen har ocksa applicerats till en MIMO-situation.En jamforelse mellan den foreslagna algoritmen och turboutjamning hargjorts.
APA, Harvard, Vancouver, ISO, and other styles
4

Jersenius, Kristina. "Uplink Channel Dependent Scheduling for Future Cellular Systems." Thesis, Linköping University, Department of Electrical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8213.

Full text
Abstract:
<p>One goal in the development of future cellular systems is to increase performance. Channel dependent scheduling can possibly contribute to a performance enhancement. It requires channel qualityinformation and uplink channel knowledge is often incomplete. This master thesis work compares channel dependent scheduling and channel independent scheduling for a Single Carrier Frequency Division Multiple Access-based uplink in time domain and time and frequencydomain assuming continuous channel quality information updates. It also evaluates different methods for providing channel quality information by investigating how the limited channel knowledge they supply affects the performance of channel dependent scheduling.</p><p>Single-cell simulations with perfect channel knowledge indicate small gains for channel dependent scheduling. Large gains are seen when performing frequency and time domain scheduling instead of only time domain scheduling. Limited channel knowledge causes performance loss for channel dependent scheduling. The performance is only slightly decreased if a method with sufficiently frequent providing of channel quality information updates is applied.</p><p>More realistic multi-cell simulations show large gains for channel dependent scheduling. It is possible that these results are influenced by link adaptation and scheduling problems due to non predictable interference when performing dynamic scheduling. In the comparison between channel dependent and channel independent scheduling the channel dependent scheduling can benefit from the fact that the selected channel dependent scheduling algorithms result in a more static scheduling than the selected channel independent scheduling algorithms do.</p>
APA, Harvard, Vancouver, ISO, and other styles
5

Nakao, Seigo. "Study of Uplink Control Channel for LTE and LTE-Advanced." 京都大学 (Kyoto University), 2011. http://hdl.handle.net/2433/142137.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Lu, X. (Xiaojia). "Resource allocation in uplink coordinated multicell MIMO-OFDM systems with 3D channel models." Doctoral thesis, Oulun yliopisto, 2013. http://urn.fi/urn:isbn:9789526202914.

Full text
Abstract:
Abstract Uplink resource allocation strategies in modern cellular networks are studied in this thesis. With the presence of multiple antenna transmission, multiple base station (BS) coordination and multicarrier techniques, the resource allocation problem is reformulated and jointly optimized over a large set of variables. The focus is on the sum power minimization with per user rate constraints. A centralized multicarrier coordinated cellular network with multiple antennas implemented at the BS side is considered, where BSs can be adaptively clustered to detect signals from one mobile station (MS). The power, subcarrier, beamforming vector and BS cluster (BSC) are the design variables to be jointly optimized to satisfy the rate constraint per user. The first considered scenario is a simple single carrier multicell system. The power control problem with per user rate constraint can be optimally solved by the proposed algorithm, where power vector, BSC and beamforming vectors are separately updated until the sum power converges. The scenario is extended to more complicated multicarrier systems. The resource allocation problem is non-deterministic polynomial-time hard (NP-hard). Suboptimal algorithms are proposed to tackle the problem. To get more insights to the performance gap between the proposed algorithms and the capacity achieving bound, the scenario is specified to a single cell system with nonlinear receiver so that the calculation of the lower bound is possible. Efficient geometric aided fast converging power minimization algorithms are proposed to calculate the power bound of the multiple access channel (MAC) with per user rate constraint. By comparing the capacity achieving lower bound with the proposed algorithm, the BSW that starts from full rate allocation looks promising to have a good tradeoff between the convergence speed and the sum power consumption. Besides the resource allocation algorithms in the cellular network, the physical modeling and corresponding design of the network itself are also considered. The radio propagation in the elevation domain is modeled and considered. The diversity gain from the elevation domain is achieved by extra degree of freedom of beamforming in elevation domain. The antenna array can be either a uniform linear array or a uniform planar array with elements placed horizontally. The proposed power control algorithms are simulated in the 3D network scenarios. The effects of antenna array design in different propagation scenarios are compared<br>Tiivistelmä Työssä tutkitaan ylälinkin resurssien kohdentamisstrategioita matkapuhelinverkoissa. Olettaen koordinointi useiden monikantoaaltotekniikoita käyttävien moniantennitukiasemien (BS) välillä, resurssien kohdentamisongelma muotoillaan uudelleen ja optimoidaan yli suuren joukon optimointimuuttujia. Erityisesti keskitytään yhteenlasketun tehon minimointiongelmaan käyttäjäkohtaisien siirtonopeusrajoitteiden kanssa. Työssä oletetaan keskitetty koordinointi useiden monikantoaaltotekniikoita käyttävien moniantennitukiasemien välillä, joten tukiasemat voidaan adaptiivisesti ryhmitellä yhden matkaviestimen signaalin havannointia varten. Lähetysteho, kantoaaltoallokaatio, keilanmuodostus ja tukiasemaklusterointi ovat ongelman muuttujia, jotka optimoidaan yhdessä siten, että käyttäjäkohtaiset siirtonopeusrajoitteet täyttyvät. Ensimmäinen käsitelty tapaus on yksinkertainen yhden operaattorin monisolujärjestelmä. Tehonsäätöongelma käyttäjäkohtaisten siirtonopeusrajoitusten kanssa voidaan optimaalisesti ratkaista ehdotetulla algoritmilla, jossa lähetysteho, keilanmuodostusvektorit ja tukiasemaklusterointi päivitetään erikseen, kunnes yhteenlaskettu teho suppenee. Tarkastelu laajennetaan monimutkaisempaan monikantoaaltojärjestelmään. Kun käyttäjäkohtainen siirtonopeustavoite kiinnitetään, ongelma voidaan vastaavasti hajottaa osittaisiksi alikantoaaltokohtaisiksi osaongelmiksi, jossa kukin osaongelma voidaan optimaalisesti ratkaista. Jos alikantoaaltokohtaista siirtonopeustavoitetta ei ole kiinnitetty, tehonsäätöongelmasta tulee ei-polynomisesti monimutkainen. Optimaalisia algoritmeja ehdotetaan ongelman ratkaisemiseksi. Jotta voitaisiin saada tietoa todellisesta suorituskykyerosta ehdotettujen algoritmien ja kapasiteettioptimaalisen rajan välillä, vertailu tehdään yhden solun simulointimallissa epälineaarisen vastaanottimen kanssa siten, että kapasiteettioptimaalisen alarajan laskeminen on mahdollista. Tätä varten kehitetään tehokas geometria-avusteinen ja nopeasti konvergoituva algoritmi tehon minimointia varten käyttäjäkohtaisten siirtonopeusrajoitusten kanssa. Vertaamalla kapasiteettioptimaalista alarajaa ehdotettujen algoritmien suorituskykyyn huomataan, että ehdotettu BSW algoritmi on hyvä kompromissi konvergoitumisnopeuden ja tehonkulutuksen välillä. Matkapuhelinverkkojen resurssienkohdentamisalgoritmien lisäksi työssä huomioidaan myös verkon fyysinen mallintaminen ja vastaava suunnittelu. Työssä mallinnetaan radiokanavan ominaisuudet myös korkeustasossa, joka mahdollistaa diversiteetin hyödyntämisen korkeustason keilanmuodostuksessa. Antenniryhmä voi olla joko yhtenäinen lineaarinen ryhmä tai yhtenäinen tasoryhmä, jossa antennielementit on sijoitettu tasoon. Ehdotettuja tehonsäätöalgoritmeja simuloidaan kolmiulotteisessa verkkoskenaarioissa, jossa verrataan antenniryhmäsuunnittelun vaikutuksia eri radiokanavaskenaarioissa
APA, Harvard, Vancouver, ISO, and other styles
7

Kanagasabai, Aswin. "On Design and Analysis of Channel Aware LTE Uplink and Downlink Scheduling Algorithms." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/32735.

Full text
Abstract:
In the past two decades, there has been a drastic increase in the mobile traffic, which is caused by the improved user experience with smart phones and its applications. In LTE system, the packet scheduler plays a vital role in the effective utilization of the resources. This field is not standardized and has immense scope of improvement, allowing vendor-specific implementation. The work presented in this thesis focuses on designing new scheduling algorithms for uplink and downlink to effectively distribute resources among the users. LTE scheduling can be categorized into two extremes, namely, Opportunistic scheduling and Fairness scheduling. The Best Channel Quality Indicator (BCQI) algorithm falls under the former category while Proportional Fairness (PF) algorithm under the later. BCQI algorithm provides high system throughput than PF algorithm, however, unlike BCQI algorithm, PF algorithm considers users with poor channel condition for allocation process. In this work, two new scheduling disciplines referred as Opportunistic Dual Metric (ODM) Scheduling Algorithm is proposed for uplink and downlink respectively. The objective of the algorithm is to prioritize the users with good channel condition for resource allocation, at the same time not to starve the users with poor channel conditions. The proposed algorithm has two resource allocation matrices, H1 and H2, where H1 is throughput-centric and H2 is fairness-centric. The uplink algorithm uses the two resource allocation matrices to allocate the resources to the users and to ensure contiguous resource allocation. The downlink algorithm is an extension of the proposed uplink algorithm avoiding uplink constraints. The downlink algorithm employs the two resource distribution matrices to provide an efficient resource allocation by expanding the allocation for the users considering intermittent resources. The performance of ODM is measured in terms of throughput, fairness. Additionally, the uplink algorithm is analysed in terms of transmit power. From the results it is observed that the proposed algorithms has better trade-off in terms of all the performance parameters than PF scheduler and BCQI scheduler.
APA, Harvard, Vancouver, ISO, and other styles
8

Punnoose, Sonu. "Blind channel estimation and layered space frequency equalisation for MIMO CDMA uplink systems." Thesis, University of Liverpool, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433038.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Shi, Wei. "Uplink Power Control and Soft Handoff Prioritization in Multimedia DS-CDMA." ScholarWorks@UNO, 2006. http://scholarworks.uno.edu/td/322.

Full text
Abstract:
In the CDMA cellular networking system, power control is a very important issue because it is an interference limited system. In order to reduce the near-far problem and improve the battery life of mobile station, the transmit power of mobile stations must be controlled to limit interference. In this paper, we study the effect of power control on system performance. Different power control rates may have influence on the performance. Meanwhile, we take the consideration of different call admission control algorithm. By introducing soft handoff waiting queue and guard channel into the soft handoff algorithm, we compare the power control influence on a base case (which is similar to IS95 algorithm, but with perfect power control) and proposed call admission control algorithm. The simulation shows that increasing power control rate and combination of power control and soft handoff prioritization can greatly reduce the blocking rates and refuse rates of new/soft handoff calls, thus the system performance is improved.
APA, Harvard, Vancouver, ISO, and other styles
10

Dimou, Konstantinos. "Améliorations de l'accès paquet en sens montant du WCDMA." Phd thesis, Télécom ParisTech, 2003. http://pastel.archives-ouvertes.fr/pastel-00000671.

Full text
Abstract:
Les systèmes de 3G offrent de nouveaux services support (bearer services) à plus hauts débits pour les modes de transmission "paquet". Ces services vont coexister avec la voix (ou d'autres services temps réels), des scénarios de trafic mixte, voix et données, doivent être envisagés. La norme UMTS permet effectivement aux utilisateurs d'avoir plus d'un service activé simultanément. Les différentes classes de trafic augmentent la complexité de la gestion des ressources radios. Dans ce contexte, deux types de fonctions sont étudiés: l'allocation de TFCI et l'ordonnancement de paquets. Leur impact sur la qualité de service (QoS) ainsi que sur la capacité du système est évalué. On propose des améliorations de ces mécanismes dans le but d'augmenter la capacité du système et par conséquent d'améliorer la QoS des utilisateurs. Les études se restreignent au sens montant, c'est à dire aux transmissions du mobile (User Equipment ou UE) vers le réseau. Un premier mécanisme pour lequel un effort d'amélioration est fait, est l'adaptation du lien radio par variation du débit instantané transmis. On simule le cas d'une transmission multiservice (voix et données). L'UE doit partager un débit global qui lui est alloué entre les différents services activés. Ces derniers sont véhiculés dans des radio bearers (tuyaux supports). À chaque intervalle élémentaire de transmission (Transmission Time Interval, TTI), l'UE sélectionne un sous-débit pour chaque bearer; ceci se fait par la sélection d'un "format de transport" à appliquer pendant la durée TTI. Cette procédure s'effectue dans la couche MAC (Medium Access Control); le résultat de la sélection est une combinaison de formats de transport (Transport Format Combination, TFC) que la couche physique doit utiliser. La procédure, nommée sélection de TFC, permet d'adapter la transmission des différents services aux conditions variables de la propagation radio: elle détermine notablement la performance de transmission. L'algorithme de sélection de TFC est tracé dans ses grandes lignes dans la norme. Un de ses principes est de favoriser le trafic temps réel au détriment des services de données par paquet. Cependant, le trafic temps réel peut être perturbé par le trafic de données sous certaines conditions, en particulier pour les mobiles éloignés de la station de base (Node B). On propose un algorithme de sélection de TFC qui limite ces perturbations et qui offre une plus large zone de couverture aux services temps réels. En plus, il améliore la QoS du service de données et le débit effectif de l'UE sans augmenter sa puissance de transmission. Un autre type d'études concerne l'ordonnancement de paquets entre les différents utilisateurs ou UEs. C'est une procédure qui est contrôlée par la partie fixe du réseau. Nous l'étudions principalement par simulation en considérant divers mécanismes ou variations. Un premier mécanisme est nommé fast Variable Spreading Factor (fast VSF): les UEs distants changent rapidement leur facteur d'étalement (SF) afin de conserver une puissance de transmission constante, ce qui vise à stabiliser l'interférence inter-cellulaire. Un deuxième mécanisme étudié est un accès paquet décentralisé (decentralized mode) utilisant une information en retour sur le niveau global d'interférence dans la cellule. Un troisième mécanisme nommé "fast scheduling" (ordonnancement rapide) raccourcit le cycle d'ordonnancement. Les résultats ont montré que dans le cas de faible ou moyenne charge dans la cellule, le mode décentralisé réduit le délai par paquet jusqu'à 25 %. L'ordonnancement rapide augmente la capacité du système jusqu' à 10%. En plus, il améliore la QoS perçue par les utilisateurs en terme de débit par utilisateur et délai par paquet transmis.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Uplink channel"

1

Ndenecho, Emmanuel Neba. Landslide and torrent-channel problems of mountain slopes: Processes and management options for Bamenda Highlands. Unique Printers Bamenda, 2007.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Sonderman, David L. Stem-quality changes on young, mixed, upland hardwoods after crop-tree release. U.S. Dept. of Agriculture, Forest Service, Northeastern Forest Experiment Station, 1987.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

Northeastern Forest Experiment Station (Radnor, Pa.), ed. Stem-quality changes on young, mixed, upland hardwoods after crop-tree release. U.S. Dept. of Agriculture, Forest Service, Northeastern Forest Experiment Station, 1989.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

Sonderman, David L. Stem-quality changes on young, mixed, upland hardwoods after crop-tree release. U.S. Dept. of Agriculture, Forest Service, Northeastern Forest Experiment Station, 1987.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

Sonderman, David L. Stem-quality changes on young, mixed, upland hardwoods after crop-tree release. U.S. Dept. of Agriculture, Forest Service, Northeastern Forest Experiment Station, 1987.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

Sonderman, David L. Stem-quality changes on young, mixed, upland hardwoods after crop-tree release. U.S. Dept. of Agriculture, Forest Service, Northeastern Forest Experiment Station, 1987.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

Giese, G. S. Passive retreat of Massachusetts coastal upland due to relative sea-level rise. Massachusetts Coastal Zone Management, Massachusetts Coastal Submergence Program, 1987.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

Monsalud, Florentino C. Stabilization of upland agriculture under El Nino-induced climatic risk: Impact assessment and mitigation measures in the Philippines. CGPRT Centre, Regional Co-ordination Centrefor Research and Development of Coarse Grains, Pulses, Roots and Tuber Crops in the Humid Tropics of Asia and the Pacific, 2003.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
9

Bang, Sergie K. Stabilization of upland agriculture under El Nino-induced climatic risk: Impact assessment and mitigation measures in Papua New Guinea. CGPRT Centre, Regional Co-ordination Centre for Research and Development of Coarse Grains, Pulses, Roots and Tuber Crops in the Humid Tropics of Asia and the Pacific, 2003.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
10

Frisina, Michael R. Weather & wildlife: An annotated bibliography. Montana Dept. of Fish, Wildlife & Parks, 2008.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Book chapters on the topic "Uplink channel"

1

Love, Robert, and Vijay Nangia. "Uplink Physical Channel Structure." In LTE - The UMTS Long Term Evolution. John Wiley & Sons, Ltd, 2011. http://dx.doi.org/10.1002/9780470978504.ch16.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Kumar, Venkataramani, and Feng Ye. "Analysis of Reciprocity Based Downlink Channel Estimation with Uneven Uplink Channel." In Lecture Notes in Networks and Systems. Springer Nature Switzerland, 2024. http://dx.doi.org/10.1007/978-3-031-67447-1_23.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Hajipour, Javad, Amr Mohamed, and Victor C. M. Leung. "Channel Aware and Queue Aware Scheduling in LTE Uplink." In Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering. Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-29222-4_9.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Borkar, Vivek S., and Joy Kuri. "Optimal Distributed Uplink Channel Allocation: A Constrained MDP Formulation." In Annals of the International Society of Dynamic Games. Birkhäuser Boston, 2010. http://dx.doi.org/10.1007/978-0-8176-8089-3_21.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Simeone, Osvaldo, Jinkyu Kang, Joonkhyuk Kang, and Shlomo Shamai Shitz. "Cloud Radio Access Networks: Uplink Channel Estimation and Downlink Precoding." In Signal Processing for 5G. John Wiley & Sons, Ltd, 2016. http://dx.doi.org/10.1002/9781119116493.ch18.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Kashkevich, Svitlana, Olena Shaposhnikova, Nataliia Saienko, Viktoriia Shevchenko, Nataliia Holeho, and Taras Zaloznyi. "Intellectual methods for evaluating the state of UAV channels." In DECISION SUPPORT SYSTEMS: MATHEMATICAL SUPPORT. TECHNOLOGY CENTER PC, 2025. https://doi.org/10.15587/978-617-8360-13-9.ch5.

Full text
Abstract:
In this section of the research, intellectual methods for assessing the state of unmanned aerial vehicle (UAV) channels are proposed. During the study, the authors: 1. Developed an intellectual method for assessing the state of UAV channels based on the application of fuzzy set theory and artificial neural networks, which, while being sufficiently simple, allows for obtaining highly accurate solutions. The distinctive features of the proposed method include:– simultaneous assessment of the UAV channel state based on multiple evaluation indicators (impulse response, frequency response, and bit error rate);– real-time continuous assessment of several channel state characteristics;– continuous assessment of multiple channel state characteristics in both the downlink and uplink channels;– obtaining channel state assessments for each indicator on separate layers of the neural network through the construction of membership functions;– following the assessment of individual channel characteristics by separate neural network layers, a generalized channel state assessment is formed at their output. 2. Proposed a methodology for identifying the state of UAV control and data transmission channels.The novelty of the proposed methodology lies in:– considering a corrective coefficient during calculations to account for the degree of uncertainty regarding the state of UAV channels;– adding a corrective coefficient to address data noise resulting from distortions in information about UAV channel states;– reducing computational costs when assessing the state of UAV channels;– enabling calculations with input data of various natures and units of measurement.
APA, Harvard, Vancouver, ISO, and other styles
7

Steiner, Bernd. "Time Domain Uplink Channel Estimation in Multicarrier-CDMA Mobile Radio System Concepts." In Multi-Carrier Spread-Spectrum. Springer US, 1997. http://dx.doi.org/10.1007/978-1-4615-6231-3_18.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Kuo, Fang-Chang, Chih-Cheng Tseng, Kuo-Chang Ting, and Hwang-Cheng Wang. "Resource Allocation Scheme for LTE Uplink Transmission Based on Logical Channel Groups." In Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering. Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-60717-7_35.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Zhang, Qiuxia, Yuanjie Deng, and Chao Song. "Research on Channel Estimation of Uplink for MC-CDMA Based on OFDM." In Advances in Intelligent and Soft Computing. Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-25661-5_78.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Deepak, N. R., and S. Balaji. "Uplink Channel Performance and Implementation of Software for Image Communication in 4G Network." In Advances in Intelligent Systems and Computing. Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-33622-0_10.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Uplink channel"

1

Nguyen, Tung T., Brian Berscheid, Ha H. Nguyen, and Eric Salt. "Iterative Channel Estimation for DOCSIS 3.1 Uplink Channels." In GLOBECOM 2016 - 2016 IEEE Global Communications Conference. IEEE, 2016. http://dx.doi.org/10.1109/glocom.2016.7841919.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Ho, Kenneth, and Andres Kwasinski. "Uplink Channel Estimation in WiMAX." In 2009 IEEE Wireless Communications and Networking Conference. IEEE, 2009. http://dx.doi.org/10.1109/wcnc.2009.4918011.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Gurgunoglu, Dogga, and Sinan Gezici. "Channel Estimation Methods for 5G Physical Uplink Control Channels." In 2020 28th Signal Processing and Communications Applications Conference (SIU). IEEE, 2020. http://dx.doi.org/10.1109/siu49456.2020.9302058.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Hayashi, Kazunori, and Hideaki Sakai. "Uplink Channel Estimation for OFDMA System." In 2007 IEEE International Conference on Acoustics, Speech, and Signal Processing. IEEE, 2007. http://dx.doi.org/10.1109/icassp.2007.366528.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Zhou, Meili, Bin Jiang, Wen Zhong, and Xiqi Gao. "Efficient channel estimation for LTE uplink." In Signal Processing (WCSP 2009). IEEE, 2009. http://dx.doi.org/10.1109/wcsp.2009.5371577.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Aiping Huang, M. Hall, and I. Hartimo. "Multipath channel estimation for WCDMA uplink." In Gateway to 21st Century Communications Village. VTC 1999-Fall. IEEE VTS 50th Vehicular Technology Conference (Cat. No.99CH36324). IEEE, 1999. http://dx.doi.org/10.1109/vetecf.1999.797073.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Choi, Sung-Woo, Hee-Sang Chung, Ilgyu Kim, and Jae-Min Ahn. "Uplink control channel of mobile hotspot network." In 2015 International Conference on Information and Communication Technology Convergence (ICTC). IEEE, 2015. http://dx.doi.org/10.1109/ictc.2015.7354574.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Ghosh, Amitava, Rapeepat Ratasuk, Weimin Xiao, et al. "Uplink Control Channel Design for 3GPP LTE." In 2007 IEEE 18th International Symposium on Personal, Indoor and Mobile Radio Communications. IEEE, 2007. http://dx.doi.org/10.1109/pimrc.2007.4394263.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Grakhova, Elizaveta P., Grigory S. Voronkov, Arsen A. Ishmiyarov, Valeriy K. Bagmanov, and Albert K. Sultanov. "Performance analysis of the RoF uplink channel." In Eighteenth lnternational Scientific and Technical Conference "Optical Technologies for Telecommunications", edited by Vladimir A. Burdin, Anton V. Bourdine, Vladimir A. Andreev, Oleg G. Morozov, and Albert C. Sultanov. SPIE, 2021. http://dx.doi.org/10.1117/12.2593053.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

El-Keyi, Amr, and Benoit Champagne. "Robust Channel Feedback for Collaborative Uplink Beamforming." In 2007 IEEE International Symposium on Signal Processing and Information Technology. IEEE, 2007. http://dx.doi.org/10.1109/isspit.2007.4458087.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Uplink channel"

1

List, Nancy, and Ryan Shoup. Incorporation of Uplink Channel State Information into an End-to-End Coded Satellite Communication System. Defense Technical Information Center, 2011. http://dx.doi.org/10.21236/ada569700.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Sonderman, David L., and David L. Sonderman. Stem-quality changes on young, mixed upland hardwoods after crop-tree release. U.S. Department of Agriculture, Forest Service, Northeastern Forest Experimental Station, 1987. http://dx.doi.org/10.2737/ne-rp-597.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Sonderman, David L., and David L. Sonderman. Stem-quality changes on young, mixed upland hardwoods after crop-tree release. U.S. Department of Agriculture, Forest Service, Northeastern Forest Experimental Station, 1987. http://dx.doi.org/10.2737/ne-rp-597.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Walshire, Lucas, Joseph Dunbar, and Benjamin Breland. Stability analysis of Old River Low Sill Structure. Engineer Research and Development Center (U.S.), 2022. http://dx.doi.org/10.21079/11681/45349.

Full text
Abstract:
An updated stability analysis was performed on the Old River Low Sill Structure due to a change in the operating conditions from historic river sedimentation. Sedimentation of the Mississippi River channel since the 1973 spring flood has caused higher river stages at lower discharges. Numerical methods used included nonlinear analysis of pile group stability, seepage analyses, and limit equilibrium methods. The structure’s foundation was compromised during the 1973 flood, and emergency repairs were conducted to prevent scouring and undermining of the foundation by the flood scour. Rehabilitation included the reconstruction of a failed wing wall on the left abutment, rock and riprap fill in the forebay channel, and emergency grouting to fill the scour hole beneath the structure. An operating restriction was emplaced to limit the differential head across the structure due to flood damage. Taking these conditions into account, results from an updated analysis showed that full headwater uplift caused increased tension in the piles, while the increased body load caused increased compressive loads in the piles. Review of piezometric monitoring and the seepage analyses showed that full headwater uplift is unlikely, indicating the foundation grouting adequately sealed the scour hole beneath the structure. Analysis results exhibited lower magnitude compression and tension loads in the piles with design load cases compared to previous analyses. Recommendations from these analyses indicate that increased monitoring and additional investigation may support increasing the differential head limitation.
APA, Harvard, Vancouver, ISO, and other styles
5

Rosse, Anine. Stream channel monitoring for Wind Cave National Park 2021 Data report. National Park Service, 2023. http://dx.doi.org/10.36967/2296623.

Full text
Abstract:
The Northern Great Plains Inventory and Monitoring Network (NGPN) began stream channel monitoring in Highland Creek at Wind Cave National Park (WICA) in 2021. This data report summarizes the data collected during the 2021 season pertaining to watershed, reach, and physical habitat. After data are collected for at least four cycles, trends may be reported. This report covers three main areas: 1) Reporting on upland channel characteristics data that may affect habitat such as: land cover, drainage area, and total stream length; 2) Reporting of geomorphic dimensions such as: channel widths, bank angles, vegetative cover, reach slope, measures of bank stability; and 3) Determining physical habitat characteristics such as: size and distribution of bed sediment, large woody debris, and canopy cover. Indices, benchmarks, and other studies are provided in the table for informational purposes to help put Highland Creek’s measurements in context but should not be considered as a reference condition. Upland characteristics of the watershed indicate high natural land use cover (forest, grassland, and shrubland) with little development in the area. Reach characteristics include bank cover, heights, bank stability index, and vegetative cover. In addition to animal-induced erosion of the banks, bank sloughing and widening are occurring. Angles are steep, and there are some sandy banks that are unstable. When plots are revisited in three years, there will be greater understanding of the processes at play and the condition of the stream. Physical characteristics include median particle size, percentage fine substrate, geomorphic units, and canopy cover. Gravel substrate still covers much of the stream; there are wide meanders in the stream bed; and a variety of geomorphic channel units (pool, riffle, run) occur in the creek all of which are indicators of healthy habitat. While there is an absence of large woody debris and canopy cover is low, many grassland streams in good condition can have similar characteristics. More data are needed to fully assess those components and determine a suitable reference condition that can be used to later assess the status and trends of Highland Creek. The reach data contained in this report are specific to a short 150-m segment of Highland Creek and cannot be extrapolated to conditions elsewhere in the creek or to the park in general. Bank erosion and bank instability were observed along the majority of transects at site WICA SCM 001.
APA, Harvard, Vancouver, ISO, and other styles
6

Xu, Xiaowei, Sam Ray-Chaudhuri, and Tom Waters. Recent changes to universal credit have much smaller effect on poverty than £20 uplift. The IFS, 2023. http://dx.doi.org/10.1920/co.ifs.2023.0022.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Liu and Nixon. L52305 Probabilistic Analysis of Pipeline Uplift Resistance. Pipeline Research Council International, Inc. (PRCI), 2010. http://dx.doi.org/10.55274/r0000002.

Full text
Abstract:
To investigate the feasibility of probabilistic analyses of the peak uplift resistance in frozen soils by varying parameters that are known to be important for the development of the uplift resistance under the upward movement of a pipe. A buried pipeline will be subjected to a variety of forces, both internal and external, including the interaction of the pipe with the surrounding soil. The soil-pipe interaction in permafrost regions have to account for the behavior of frozen and unfrozen soil, and transitions between the two as the pipeline traverses in a discontinuous permafrost zone. The variations in the properties and behavior of frozen soils are expected to be substantial in three dimensions of the Right-of-Way (ROW) and with time (seasonal fluctuations and changes with the history of pipeline operation). Given the uncertainties with frozen soil properties and the changes in behavior with time and location, a large variation in soil-pipe interaction characteristics can exist. The uplift resistance of a pipeline is one of these soil-pipe interactions that can be impacted by a variation in soil condition and state. A need was identified to outline the use of a probabilistic analysis of pipe uplift resistance in an attempt to capture the magnitude of these variations and uncertainties of frozen soil and the impact on the soil-pipe interaction. The probabilistic analysis allows the designer of a pipeline to consider a range of uplift resistance to a certain confidence level that would represent the likely values that a pipe may be subjected to. The work presented in this report is more focused on the methodology of the probabilistic approach, rather than the analysis itself for a specific design case, even though an example is provided for illustration purposes. A series of numerical simulations using Fast Lagrangian Analysis of Continua (FLAC) were completed varying one parameter with each run to develop a library of peak uplift resistances for a variety of different temperatures, soil properties and pipe parameters. The FLAC model was previously developed for PRC, a summary of this report is provided here to outline important parameters that were used to complete this analysis. The simulations were used to develop a correlation of peak uplift resistance as a function of soil tensile strain limit, modulus of deformation, and creep of frozen soils. Each of these parameters is dependent of the pipeline conditions such as temperature, displacement rate, and effective frozen cover depth. It is noted that the scope of the work was to develop a probabilistic method of estimating peak uplift resistance in frozen soils. Even though some sensitivity analysis were carried out, as outlined later in this report, to assess the impacts of the variable, detailed uncertainty analysis or risk assessment were not performed.
APA, Harvard, Vancouver, ISO, and other styles
8

Boyle, M., and Elizabeth Rico. Terrestrial vegetation monitoring at Cumberland Island National Seashore: 2020 data summary. National Park Service, 2022. http://dx.doi.org/10.36967/2294287.

Full text
Abstract:
The Southeast Coast Network (SECN) conducts long-term terrestrial vegetation monitoring as part of the nationwide Inventory and Monitoring Program of the National Park Service (NPS). The vegetation community vital sign is one of the primary-tier resources identified by SECN park managers, and it is currently conducted at 15 network parks (DeVivo et al. 2008). Monitoring plants and their associated communities over time allows for targeted understanding of ecosystems within the SECN geography, which provides managers information about the degree of change within their parks’ natural vegetation. 2020 marks the first year of conducting this monitoring effort at Cumberland Island National Seashore (CUIS). Fifty-six vegetation plots were established throughout the park from May through July. Data collected in each plot included species richness across multiple spatial scales, species-specific cover and constancy, species-specific woody stem seedling/sapling counts and adult tree (greater than 10 centimeters [3.9 inches {in}]) diameter at breast height (DBH), overall tree health, landform, soil, observed disturbance, and woody biomass (i.e., fuel load) estimates. This report summarizes the baseline (year 1) terrestrial vegetation data collected at Cumberland Island National Seashore in 2020. Data were stratified across three dominant broadly defined habitats within the park, including Coastal Plain Upland Open Woodlands, Maritime Open Upland Grasslands, and Maritime Upland Forests and Shrublands. Noteworthy findings include: 213 vascular plant taxa (species or lower) were observed across 56 vegetation plots, including 12 species not previously documented within the park. The most frequently encountered species in each broadly defined habitat included: Coastal Plain Upland Open Woodlands: longleaf + pond pine (Pinus palustris; P. serotina), redbay (Persea borbonia), saw palmetto (Serenoa repens), wax-myrtle (Morella cerifera), deerberry (Vaccinium stamineum), variable panicgrass (Dichanthelium commutatum), and hemlock rosette grass (Dichanthelium portoricense). Maritime Open Upland Grasslands: wax-myrtle, saw greenbrier (Smilax auriculata), sea oats (Uniola paniculata), and other forbs and graminoids. Maritime Upland Forests and Shrublands: live oak (Quercus virginiana), redbay, saw palmetto, muscadine (Muscadinia rotundifolia), and Spanish moss (Tillandsia usneoides) Two non-native species, Chinaberry (Melia azedarach) and bahiagrass (Paspalum notatum), categorized as invasive by the Georgia Exotic Pest Plant Council (GA-EPPC 2018) were encountered in four different Maritime Upland Forest and Shrubland plots during this monitoring effort. Six vascular plant species listed as rare and tracked by the Georgia Department of Natural Resources (GADNR 2022) were observed in these monitoring plots, including the state listed “Rare” Florida swampprivet (Forestiera segregata var. segregata) and sandywoods sedge (Carex dasycarpa) and the “Unusual” green fly orchid (Epidendrum conopseum). Longleaf and pond pine were the most dominant species within the tree stratum of Coastal Plain Upland Open Woodland habitat types; live oak was the most dominant species of Maritime Upland Forest and Shrubland types. Saw palmetto and rusty staggerbush (Lyonia ferruginea) dominated the sapling stratum within Maritime Upland Forest and Shrubland habitat types. Of the 20 tree-sized redbay trees measured during this monitoring effort only three were living and these were observed with severely declining vigor, indicating the prevalence and recent historical impact of laurel wilt disease (LWD) across the island’s maritime forest ecosystems. There was an unexpectedly low abundance of sweet grass (Muhlenbergia sericea) and saltmeadow cordgrass (Spartina patens) within interdune swale plots of Maritime Open Upland habitats on the island, which could be a result of grazing activity by feral horses. Live oak is the dominant tree-sized species across...
APA, Harvard, Vancouver, ISO, and other styles
9

Boyle, Maxwell. Terrestrial vegetation monitoring at Canaveral National Seashore: 2022 data summary. National Park Service, 2024. http://dx.doi.org/10.36967/2303291.

Full text
Abstract:
The Southeast Coast Network (SECN) conducts long-term terrestrial vegetation monitoring as part of the NPS Inventory and Monitoring Program. The vegetation community vital sign is one of the primary-tier resources identified by SECN park managers, and monitoring is conducted at 15 network parks (DeVivo et al. 2008). Monitoring plants and their associated communities over time allows for targeted understanding of ecosystems within the SECN geography, which provides managers information about the degree of change within their parks? natural vegetation. 2022 marked the first year of conducting this monitoring effort at Canaveral National Seashore (CANA). Fourteen vegetation plots were established throughout the park in April. Data collected in each plot included species richness across multiple spatial scales, species-specific cover and constancy, species-specific woody stem seedling/sapling counts and adult tree (greater than 10 centimeters [3.9 inches {in}]) diameter at breast height (DBH), overall tree health, landform, soil, observed disturbance, and woody biomass (i.e., fuel load) estimates. This report summarizes the baseline (year 1) terrestrial vegetation data collected at Canaveral National Seashore in 2022. Data were stratified across two dominant broadly defined habitats within the park, Coastal Plain Upland Open Woodlands and Maritime Upland Forests and Shrublands. Noteworthy findings include: 176 vascular plant taxa were observed across 14 vegetation plots, including seven species not previously documented within the park. The most frequently encountered species in each broadly defined habitat included: Coastal Plain Upland Open Woodlands: saw palmetto (Serenoa repens), dune greenbrier (Smilax auriculata), Elliott?s milkpea (Galactia elliottii), myrtle oak (Quercus myrtifolia), Chapman oak (Quercus chapmanii), and southern evergreen blueberry (Vaccinium myrsinites). Maritime Upland Forests and Shrublands: live oak (Quercus virginiana), muscadine (Muscadinia rotundifolia var. rotundifolia), saw palmetto, cabbage palmetto (Sabal palmetto), dune greenbrier, and Virginia creeper (Parthenocissus quinquefolia). Four non-native species categorized as invasive by the Florida Invasive Species Council (FISC 2019) were encountered within Maritime Upland Forest and Shrubland plots during this monitoring effort. These included Brazilian peppertree (Schinus terebinthifolia), cogongrass (Imperata cylindrica), common lantana (Lantana strigocamara), and caesarweed (Urena lobata). There were no invasive species observed in Coastal Plain Upland Open Woodland plots. Two species listed as Endangered by the state of Florida (FDACS 2021) were encountered on the park during this monitoring effort and included hand fern (Cheiroglossa palmata) and Atlantic Coast Florida lantana (Lantana depressa var. floridana). Hand fern was observed in 30%of Maritime Upland Forest and Shrubland plots, while lantana was observed in one (10%) of Maritime Upland Forest and Shrubland plots. An additional five vascular species categorized as Commercially Exploited by the state of Florida (FDACS 2021) were also observed in these vegetation plots. Slash pine (Pinus elliottii) or South Florida slash pine (Pinus densa) and sand live oak (Quercus geminata) were the most dominant species within the tree stratum of Coastal Plain Upland Open Woodlands within the park; cabbage palmetto and live oak were the most dominant species of Maritime Upland Forests and Shrublands, although 11 other species large enough to be measured as trees (i.e., more than 1.37 meters (4.5 ft) in height and greater than or equal to 10 centimeters (3.9 in) in diameter at breast height (DBH) were also present within these plots. Based on these baseline findings, the most immediate threat to vegetation resources within Upland Open Woodlands of Canaveral National Seashore is related to exclusion of fire and an altered natural fire regime. These factors have likely led to a reduction of canopy species (pines) across all woody stem strata?tree, sapling, seedling?and an increase in abundance of woody shrub species (e.g., saw palmetto). These characteristics (low canopy species density and high woody shrub abundance) were observed in monitoring plots of this habitat type. The most immediate threat to Maritime Upland Forest and Shrubland habitat within the park is from potential expansion of non-native, invasive plant species, like Brazilian peppertree and cogongrass. All plots are scheduled to be resampled during the summer of 2026.
APA, Harvard, Vancouver, ISO, and other styles
10

Swan, Megan, and Christopher Calvo. Site characterization and change over time in semi-arid grassland and shrublands at three parks?Chaco Culture National Historic Park, Petrified Forest National Park, and Wupatki National Monument: Upland vegetation and soils monitoring 2007?2021. National Park Service, 2024. http://dx.doi.org/10.36967/2301582.

Full text
Abstract:
This report presents results of upland vegetation and soil monitoring of semi-arid grasslands at three Parks by the Southern Colorado Plateau Inventory and Monitoring Network (SCPN) from 2007?2021. The purpose is to compare and contrast five grassland ecological sites and examine how they have changed during the first 15 years of monitoring. Crews collected data on composition and abundance of vegetation, both at the species level and by lifeform (e.g., perennial grass, shrub, forb) and soil aggregate stability and soil texture at 150 plots within five target grassland/shrubland communities delineated using NRCS ecological site (ecosite) classification (30 plots per ecosite). Soils in plots at Petrified Forest NP and Chaco Culture NHP were deeper than those at Wupatki NM. Undifferentiated soil crust comprised the largest component of the soil surface, except at Wupatki where surface gravel dominated. Cover of biological soil crust (cyanobacteria, lichen, and moss) was low. Soil aggregate stability was moderate. From 2007?2021, SCPN crews identified 283 unique plant species. Overall live foliar cover ranged from 12-24%. Four of five ecological sites were dominated by C4 grass species (&gt;70% of total live foliar cover). Shrubs co-dominated at one site (WUPA L) and forbs were an overall small component of total vegetation cover but contributed most of the diversity in these sites. Less than 4% of species detected were nonnative. Russian thistle (Salsola tragus) was the most frequently sampled nonnative, occurring in &gt; 50% of plots at Wupatki in the volcanic upland ecological site. Cheatgrass (Bromus tectorum) was the second most common invasive species but occurred in &lt; 10% of the plots at all ecological sites. Vegetation cover was modeled using Bayesian hierarchical models and included seasonal climatic water deficits, year effects and topographic variables as covariates. Models revealed significant negative time trends (i.e., changes over time that were not explained by changes in seasonal deficit covariates included) in some modeled responses, particularly in the cover of perennial grass at all five ecological sites. Time trends in shrub and forb responses were mixed. Species richness showed variable effects by ecosite, decreasing at CHCU S, and increasing at PEFO S and WUPA V. Modeled responses were influenced by climate covariates, but direction of these effects varied. The most consistent effects were that greater July water stress and higher accumulated growing degree days (i.e., warmer spring temperatures) increased cover of perennial grasses and shrubs during the same year. However, greater water stress in the spring had a negative effect on many responses as expected. Decreasing cover of perennial grass and increasing cover of shrubs and weedy forbs has been predicted for southwestern grasslands in response to increasing aridification due to anthropogenic climate change. Perennial grass trends reported here correspond with these predictions with mixed results on shrub and forb community trends. Continued drought conditions will likely exacerbate negative changes in these systems.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Uplink channel' for particular source types:
Journal articles Dissertations / Theses Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography