1,785 research outputs found
On the Computation of 16-QAM and 64-QAM Performance in Rayleigh-Fading Channels
No full textSUMMARY Quadrature Amplitude Modulation (QAM) schemes are attractive in terms of bandwidth efficiency and offer a number of subchannels with different integrities via both Gaussian and Rayleigh-fading channels, Specifically, the 16-QAM phasor constellation has two, while the 64-QAM possesses three such subchannels, which become dramatically different via Rayleigh-fading channels. The analytically derived bit error rate (BER) formulae yield virtually identical curves with simulation results, exhibiting adequate BERs for the highest integrity subchannels of both 16-QAM and 64-QAM to be further reduced by forward error correction coding (FEC). However, the BERs of the lower integrity subchannels require fading compensation to reduce their values for FEC techniques to become effective. This property creates ground for a variety of carefully matched, embedded mobile transmission schemes of different complexities. The practical implementation of such an embedded scheme is demonstrated by a low-cost, low-complexity and low consumption 50 kBd mobile video telephone scheme offering adequate speech and image quality for channel SNRs in excess of about 20 dB via Rayleigh-fading channels. key words: QAM theory; modulation for microcellular fading channels
Fashion Culture: Constance White in conversation with Valerie Steele
No full textOn February 27, 2018, author Constance White joined Dr. Valerie Steele to discuss the influence of black style on today’s fashion vernacular, drawing on striking images of trendsetters from Josephine Baker to Michelle Obama, Rihanna, and Pharrell Williams. White’s book, How to Slay, is one of the few surveys of black style and fashion ever published
Introducing Microcells into Macrocellular Networks: A Case Study
No full textAbstract?The performance in terms of signal-to-interference ratio (SIR), teletraffic, and spectral efficiency of a combined macrocellular and microcellular network is investigated when either both types of cells share the same channel set, or when the channel set is partitioned between the macrocells and the microcells. The analysis is for time-division multiple access (TDMA) with frequency hopping, power control, and discontinuous transmission, and the radio channel is composed of an inverse fourth-power path loss law with log-normal fading. We commence by introducing a single microcell into a hexagonal cluster of macrocells before considering clustered microcells. Both omni-directional and sectorized cells are examined. We find that high reuse factors are required when channel sharing is employed. When channel partitioning is used, no co-channel interference occurs between the microcells and the macrocells allowing them to be planned independently. The reuse factors in the microcells and macrocells therefore do not need to be increased beyond conventional values. The outcome is that by opting for channel partitioning, the improvement in spectral efficiency compared to channel sharing is two to three times greater. Index Terms?Co-channel interference, land mobile radio cel-lular systems, time division multiaccess
Cellular Communications Using Aerial Platforms
No full textThis paper is devoted to the study of cellular communications using aerial platforms (APs). A set of key equations is derived that quantify the coverage area on the ground as a function of AP elevation, the operation of the adaptive multibeam antenna on the AP, and the formulation of contiguous terrestrial cells and their shapes. Specifically, we consider the deployment of an AP to provide terrestrial mobile radio communications using the universal mobile telecommunication system operating in its wide-band code-division multiple-access mode. Calculations are made of the number of users versus Eb/No for different service rates. Multi-tiered cellular structures having cells of different size that are steerable with the offered teletraffic are examined. The array structure to achieve this is identified. The preliminary results shows that an AP at a height of 21 km covers an area of radius 517 km. Up to 21 users per cell with a service rate of 8 kb/s can be accommodated in the 2.2-GHz band. These services can be provided within an area of radius 70 km with transmitted powers of less than 1 W. High system capacity is proved to be possible by constructing cells of radius as small as 100 m using square planar arrays with dimensions of less than 12 m x 12 m. The AP system provides high capacity and Doppler frequency shifts that only originate from roving mobiles
The drummer, or, The haunted-house : a comedy with a preface by Sir Richard Steele, & his letter to Mr. Congreve, concerning the author of this play, &c
No full text[Joseph Addison]Verfasser ist Joseph Addison - siehe Nicol
Fashion Culture: Misty Copeland in conversation with Valerie Steele
No full textMisty Copeland is a soloist with American Ballet Theatre. In 2007 she made history by becoming their second African American Female Soloist and the first in two decades. In September 2014, she was the first black woman to perform the lead role of Odette/Odile in American Ballet Theatre’s production of Swan Lake during the company’s first ever tour to Australia. Misty is the author of the New York Times bestselling memoir, Life in Motion (2014), co-written with Charisse Jones, and of the picture book Firebird (2014) in collaboration with Christopher Myers.Misty Copeland was in conversation with Valerie Steele at The Museum at FIT on Tuesday, November 4, 2014
Indrani Waltzes.
No full textintroduction, three sectional waltzes, and codapianoTo the Gallant Vessel Whose Name it Bears, and to Capt. W.B. Webb R.N.R. her Genial Commander, This is Most Respectfully Dedicated by the Author, R. Steele.--GlasgowJohns Hopkins University, Levy Sheet Music Collection, Box
181, Item 146R. Steele
Indrani Waltzes.
No full textintroduction, three sectional waltzes, and codapianoTo the Gallant Vessel Whose Name it Bears, and to Capt. W.B. Webb R.N.R. her Genial Commander, This is Most Respectfully Dedicated by the Author, R. Steele.--GlasgowJohns Hopkins University, Levy Sheet Music Collection, Box
181, Item 146R. Steele
Pink Symposium: Dr. Valerie Steele “Pink: The History of a Color”
No full textThe Museum at FIT presented Pink, its twentieth academic symposium. This symposium explored the significance of the color pink in fashion, art, and culture. Pink provokes exceptionally strong feelings of both attraction and repulsion, yet it is increasingly being regarded as cool and androgynous, powerful and political. Topics included the significance of pink clothing in western and non-western cultures (including India, Africa, Mexico, and Japan), the role of pink in eighteenth-century portraiture, associations of pink with politics, gender, and sexuality, and the use of pink in cinema.Dr. Valerie Steele is director and chief curator of MFIT. Her current exhibition is Pink: The History of a Punk, Pretty, Powerful Color. She is the author or editor of numerous books, including Pink and Paris Fashion: A Cultural History
A study of two-dimensional superconductivity at oxide interfaces using waveguide resonators
No full textQN/Steele La
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