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Peak Power Reduction of OFDM Signals with Sign Adjustment
It has recently been shown that significant reduction in the peak to mean envelope power (PMEPR) can be obtained by altering the sign of each subcarrier in a multicarrier system with n subcarriers. However, finding the best sign not only requires a search over 2n possible signs but also may lead to a substantial rate loss for small size constellations. In this paper, we first propose a greedy algorithm to choose the signs based on p-norm minimization and prove that the resulting PMEPR is guaranteed to be less than c log n where c is a constant independent of n for any n. This approach has lower complexity in each iteration compared to the derandomization approach of while achieving similar PMEPR reduction. We further improve the performance of the proposed algorithm by enlarging the search space using pruning. Simulation results show that PMEPR of a multicarrier signal with 128 subcarriers can be reduced to within 1.6 dB of the PMEPR of a single carrier system. In the second part of the paper, we address the rate loss by proposing a block coding scheme in which only one sign vector is chosen for K different modulating vectors. The sign vector can be computed using the greedy algorithm in n iterations. We show that the multi-symbol encoding approach can reduce the rate loss by a factor of K while achieving the PMEPR of c logKn, i.e., only logarithmic growth in K. Simulation results show that the rate loss can be made smaller than %10 at the cost of only 1 db increase in the resulting PMEPR for a system with 128 subcarriers
Implementation of a High Throughput Soft MIMO Detector on GPU
Multiple-input multiple-output (MIMO) significantly increases the throughput of a communication system by employing multiple antennas at the transmitter
and the receiver. To extract maximum performance from a MIMO system, a computationally intensive search based detector is needed. To meet the challenge
of MIMO detection, typical suboptimal MIMO detectors are ASIC or FPGA designs. We aim to show that a MIMO detector on Graphic processor unit (GPU),
a low-cost parallel programmable co-processor, can achieve high throughput and can serve as an alternative to ASIC/FPGA designs. However, careful architecture
aware software design is needed to leverage the performance offered by GPU. We propose a novel soft MIMO detection algorithm, multi-pass trellis traversal
(MTT), and show that we can achieve ASIC/FPGA-like performance and handle different configurations in software on GPU. The proposed design can be used
to accelerate wireless physical layer simulations and to offload MIMO detection processing in wireless testbed platforms.NokiaNokia Siemens Networks (NSN)Texas InstrumentsXilinxNational Science Foundatio
Growing Kiwiberries in New England: A Guide for Regional Producers
The kiwiberry (Actinidia arguta) has an extensive 140-year history of being grown in New England as an ornamental vine but has only recently been adopted as a commercial fruit crop. As regional and international acreage in commercial production continues to increase, the need for a comprehensive production guides and regionally-specific enterprise analyses has become evident. This thesis brings together the most recent findings of the Kiwiberry Development Program at the New Hampshire Agricultural Experiment Station, along with available commercial kiwiberry production information, to address this need. Specifically, this guide presents an overview of the species, current best production practices, regionally-relevant market information, and an enterprise analysis for this emerging fruit crop in the northeastern US
Fruit crops, 1986: a summary of research
Influence of treatments at planting on trellised apple tree performance / David C. Ferree -- Influence of growth regulators on branching of young apple trees / David C. Ferree and John C. Schmid -- Influence of growth regulators on scarf skin of Rome Beauty apples / David C. Ferree and John C. Schmid -- Influence of fungicides on scarf skin on Gallia Beauty / David C. Ferree and Michael A. Ellis -- Little relationship between root pruning and winter injury / James R. Schupp and David C. Ferree -- Performance of two apple cultivars on MS and M9 interstems on Antonovka / D. C. Ferree, R. M. McConnell, and J. C. Schmid -- Air sprayer jet deflection by travel or wind: as predicted by computer / R. D. Fox, R. D. Brazee, and D. L. Reichard -- Measuring atmospheric water vapor / R. D. Brazee and R. D. Fox -- A prototypic pollination unit made from expanded polystyrene / James E. Tew and Dewey M. Caron -- Effects of gibberellic acid (GA3) and daminozide (Alar) on growth and fruiting of Himrod grapes / G. A. Cahoon, M. L. Kaps, and S. P. Pathak -- Development of an action threshold for meadow spittlebug on strawberries / Mark A. Zajac and Franklin R. Hall -- Long-term yield of selected blackberry cultivars and selections in southern Ohio / Craig K. Chandler, Donald A. Chandler, and Greg L. Brenneman -- Electronic information transfer / R. C. Funt. -- A summary of research on synthetic pyrethroids and mites in the apple orchard ecosystem / Franklin R. Hall -- Controlling apple collar rot: effects of fungicides, soil amendments, and depth of planting / M. A. Ellis, D. C. Ferree, and L. V. Madden -- Validation of an electronic unit for predicting apple scab infection periods / M. A. Ellis, L. V. Madden, and L. L. Wilson -- Epidemiology and control of strawberry leather rot / G. G. Grove, M. A. Ellis, and L. V. Madden -- Research on cane diseases of thornless blackberry in Ohio / M. A. Ellis, G. A. Kuter, and L. L. Wilso
Bulletin 22A: Papers in viticulture and Bulletin 22B: Papers in winemaking and wine evaluation
2 volume set, Papers in viticulture Bulletin 22A: Papers in viticulture; Bulletin 22B; Papers in winemaking and wine evaluation.The papers in these bulletins (22 A and B) were presented at the two courses in Grapes and Wine held at Lincoln College in November 1978
Design and Implementation of Efficient Algorithms for Wireless MIMO Communication Systems
En la última década, uno de los avances tecnológicos más importantes que han hecho culminar la nueva generación de banda ancha inalámbrica es la comunicación mediante sistemas de múltiples entradas y múltiples salidas (MIMO). Las tecnologías MIMO han sido adoptadas por muchos estándares inalámbricos tales como LTE, WiMAS y WLAN. Esto se debe principalmente a su capacidad de aumentar la máxima velocidad de transmisión , junto con la fiabilidad alcanzada y la cobertura de las comunicaciones inalámbricas actuales sin la necesidad de ancho de banda extra ni de potencia de transmisión adicional. Sin embargo, las ventajas proporcionadas por los sistemas MIMO se producen a expensas de un aumento sustancial del coste de implementación de múltiples antenas y de la complejidad del receptor, la cual tiene un gran impacto sobre el consumo de energía. Por esta razón, el diseño de receptores de baja complejidad es un tema importante que se abordará a lo largo de esta tesis.
En primer lugar, se investiga el uso de técnicas de preprocesado de la matriz de canal MIMO bien para disminuir el coste computacional de decodificadores óptimos o bien para mejorar las prestaciones de detectores subóptimos lineales, SIC o de búsqueda en árbol. Se presenta una descripción detallada de dos técnicas de preprocesado ampliamente utilizadas: el método de Lenstra, Lenstra, Lovasz (LLL) para lattice reduction (LR) y el algorimo VBLAST ZF-DFE. Tanto la complejidad como las prestaciones de ambos métodos se han evaluado y comparado entre sí. Además, se propone una implementación de bajo coste del algoritmo VBLAST ZF-DFE, la cual se incluye en la evaluación.
En segundo lugar, se ha desarrollado un detector MIMO basado en búsqueda en árbol de baja complejidad, denominado detector K-Best de amplitud variable (VB K-Best). La idea principal de este método es aprovechar el impacto del número de condición de la matriz de canal sobre la detección de datos con el fin de disminuir la complejidad de los sistemasRoger Varea, S. (2012). Design and Implementation of Efficient Algorithms for Wireless MIMO Communication Systems [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/16562Palanci
Fruit crops: a summary of research, 1998
Pesticide deposition in orchards: effects of pesticide type, tree canopy, timing, cultivar, and leaf type / Franklin R. Hall, Jane A. Cooper, and David C. Ferree -- The influence of a synthetic foraging attractant, Bee-Scent™, on the number of honey bees visiting apple blossoms and on subsequent fruit production / James E. Tew and David C. Ferree -- The reliability of three traps vs. a single trap for determining population levels of codling moth in commercial northern Ohio apple orchards / Ted W. Gastier -- Evaluation of an empirical model for predicting sooty blotch and flyspeck of apples in Ohio / Michael A. Ellis, Laurence V. Madden, and L. Lee Wilson -- Influence of pesticides and water stress on photosynthesis and transpiration of apple / David C. Ferree, Franklin R. Hall, Charles R. Krause, Bruce R. Roberts, and Ross D. Brazee -- Influence of temporary bending and heading on branch development and flowering of vigorous young apple trees / David C. Ferree and John C. Schmid -- The effect of apple fruit bruising on total returns / Richard C. Funt, Ewen A. Cameron, and Nigel H. Banks -- Yield, berry quality, and economics of mechanical berry harvest in Ohio / Richard C. Funt, Thomas E. Wall, and Joseph C. Scheerens -- Monitoring flower thrips activities in strawberry fields at two Ohio locations / Roger N. Williams, M. Sean Ellis, Dan S. Fickle, and Carl M. Pelland -- Cluster thinning effects on fruit weight, juice quality, and fruit skin characteristics in 'Reliance' grapes / Yu Gao and Garth A. Cahoon -- Effects of various fungicide programs on powdery mildew control, percent berry sugar, yield, and vine vigor of 'Concord' grapes in Ohio / Michael A. Ellis, Laurence V. Madden, L. Lee Wilson, and Gregory R. Johns -- Influence of growth regulators, cropping, and number on replacement trunks of winter-injured 'Vidal Blanc' grapes / David C. Ferree, David M. Scurlock, and Rick Evans -- Effect of new herbicides on tissue-cultured black raspberry plants / Richard C. Funt, Thomas E. Wall, and B. Dale Stokes -- Investigating the relationship between vine vigor and berry set of field-grown 'Seyval Blanc' grapevines / Steven J. McArtney and David C. Ferree -- Summary of Ohio Fruit Growers Society apple cider competition, 1993-1997 / Winston Bash and Diane Mille
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