Orbit and attitude determination results during launch support operations for SBS-5

Presented are orbit and attitude determination results from the launch of Satellite Business Systems (SBS)-5 satellite on September 8, 1988 by Arianespace. SBS-5 is a (HS-376) spin stabilized spacecraft. The launch vehicle injected the spacecraft into a low inclination transfer orbit. Apogee motor firing (AMF) attitude was achieved with trim maneuvers. An apogee kick motor placed the spacecraft into drift orbit. Postburn, reorientation and spindown maneuvers were performed during the next 25 hours. The spacecraft was on-station 19 days later. The orbit and attitude were determined by both an extended Kalman filter and a weighted least squares batch processor. Although the orbit inclination was low and the launch was near equinox, post-AMF analysis indicated an attitude declination error of 0.034 deg., resulting in a saving of 8.5 pounds of fuel. The AMF velocity error was 0.4 percent below nominal. The post-AMF drift rate was determined with the filter only 2.5 hours after motor firing. The filter was used to monitor and retarget the reorientation to orbit normal in real time

On birational involutions of P3P^3

Let $X$ be a rationally connected three-dimensional algebraic variety and let $\tau$ be an element of order two in the group of its birational selfmaps. Suppose that there exists a non-uniruled divisorial component of the $\tau$-fixed point locus. Using the equivariant minimal model program we give a rough classification of such elements.Comment: 24 pages, late

Space Division Multiplexing in Optical Fibres

Optical communications technology has made enormous and steady progress for several decades, providing the key resource in our increasingly information-driven society and economy. Much of this progress has been in finding innovative ways to increase the data carrying capacity of a single optical fibre. In this search, researchers have explored (and close to maximally exploited) every available degree of freedom, and even commercial systems now utilize multiplexing in time, wavelength, polarization, and phase to speed more information through the fibre infrastructure. Conspicuously, one potentially enormous source of improvement has however been left untapped in these systems: fibres can easily support hundreds of spatial modes, but today's commercial systems (single-mode or multi-mode) make no attempt to use these as parallel channels for independent signals.Comment: to appear in Nature Photonic

Gorenstein Formats, Canonical and Calabi–Yau Threefolds

Gorenstein formats present the equations of regular canonical, Calabi–Yau and Fano varieties embedded by subcanonical divisors. We present a new algorithm for the enumeration of these formats based on orbifold Riemann-Roch and knapsack packing-type algorithms. We apply this to extend the known lists of threefolds of general type beyond the well-known classes of complete intersections and also to find classes of Calabi-Yau threefolds with canonical singularities

Expansion Planning Of The Digital Tv Broadcasting Service In Brazil Using Sfn [planificación De La Expansión Del Servicio De Retransmisión De Tv Digital En Brasil Usando Redes Sfn]

This work aims to discuss briefly the relevant technical aspects for introduction and expansion of Digital TV retransmission services based on OFDM Multiplexing. The initial channel allocation, proposed for introduction of Digital TV in Brazil, will carry the spectral overload problems of the current analogical systems. The use of single frequency networks (SFN) appears as an efficient solution for channel allocation. © Copyright 2010 IEEE - All rights reserved.58573578Pessoa, A.C.F., (2003) Planejamento de Canais de TV Digital, Centro de Pesquisa e Desenvolvimento Em Telecomunicações CPqD, , www.anatel.gov.br, Tec. Report, septiembre deMenassian, A., (2005) Implantação de TV Digital Do Brasil, , www.anatel.gov.br, eneroYamada, F., Raunheitte, L.T.M., Sukys, F., Bedcks, G., Dantas, C., Akamine, C., Digital Signal Disturbed by Impulsive Noise in Signal of Digital TV (2004) IEEE Broadcasting MagazineCañizares, P., Torres, J.L., Martinez, J.A., VIDITER: Spanish experience on DTT (1997) 20th International Television Symposium, Montreux, Record Cable/Satellite/Terrestrial, pp. 219-224Takahshi, Y., (2005) Seminar 8: Transmission Network & Hardware (Dibeg), , www.dibeg.org, diciembreFasolo, S.A., (2001) Equalização Em Receptores de Televisão Digital de Alta Definição Utilizando Modulação 8VSB, , Tese de Doutorado, FEEC-UNICAMPFraming Structure, Channel Coding ans Modulation for Digital Terrestrial Television (1996) DVB Document A012Specification of Channel Coding, Framing Structure and Modulation (1998) Terrestrial Integrated Services Digital Broadcasting (ISDB-T) DocumentHamazumi, H., Imamura, K., Iai, N., Shibuya, K., Sasaki, M., (1998) A Loop Interference Canceller for the Relay Stations in An Single Frequency Network for Digital Terrestrial Broadcasting, , NHK Laboratories Note No. 469, Digital Broadcasting Networks Research Division(1997) DVB Mega-frame for Single Frequency Network (SFN) Synchronization, , Draft EN 301 191: Digital Video Broadcasting (DVB)European Telecommunications Standards InstituteWeiss, S.M., Reception considerations for distributed transmission in ATSC systems (2005) Consumer Electronics, ICCE Digest of Technical Paper International Conference on, pp. 477-478. , Ja

Performance Comparison Of Convolutional And Turbo Convolutional Codes For Isdb-t In Awgn And Brazilian Channels

This work intends to demonstrate the improvements applied in the Integrated System Digital Broadcasting-Terrestrial (ISDB-T). The turbo processing has been considered one of the most promising techniques for the improvement of performance in communication systems. The use of turbo convolutional codes (TCCs) combined with soft decision demapping is proposed for reduction of signal to noise rate (SNR) threshold at reception. Some simulations are done using AWGN and typical multipath brazilian channels. Therefore, it is concluded that the proposed Turbo ISDB-T performance is better than the conventional ISDB-T in those cases. © 2006 IEEE.361366(1998) Specification of Channel Coding, Framing Structure and Modulation, , Terrestrial Integrated Services Digital Broadcasting (ISDB-T) DocumentSET/ABERT Digital Television Systems - Brazilian tests - Final Report, ANATEL SP March 2000Berrou, C., Glavieux, A., Thitimajshima, P., Near Shannon Limit Error-Correcting Coding and Decoding Turbo Codes (1993) Proc. Int. Conf. Communications, pp. 1064-1070. , MayTüchler, M., Koetter, R., Singer, A.C., Turbo Equalization: Principles and New Results (2002) IEEE Transactions on Communications, 50 (5). , MaySantos, A., Guimarães, D., A Block Turbo Equalizer Scheme (2005) XXII Simpósio Brasileiro de Telecomunicaçõ es SBrT, , SeptYubing, Z., Jingming, K., Jiakang, L., Turbo ESAE channel estimation on OFDM systems (2004) 7 th International Conference on Signal Processing ICSP04, 2, pp. 1653-1656. , SeptZhijun, F., Shenghua, X., Changxuan, W., Shiqian, W., Zhengyou, W., Weiming, Z., Joint source-channel coding for MPEG-4 streams transmission over 3G networks (2005) IEEE International Conference on Wireless Communications, Networking and Mobile Computing, 2, pp. 23-26,1261-1264. , SeptHagenauer, J., Gortz, N., The turbo principle in joint source-channel coding (2003) Information Theory Workshop, pp. 275-278. , 31 March-4 AprilQiao, X., Cai, Y., Xu, Y., Joint iterative decision feedback channel estimation for turbo coded V-BLAST MIMO-OFDM systems (2005) IEEE International Symposium on Communication and Information Technology ISCIT, 2, pp. 1384-1388. , 12-14OctNavarro, M., Grant, A., Joint channel estimation and decoding for space-time turbo codes (2002) IEEE International Symposium on Information Theory, p. 161European Telecommunications Standards Institute ETSI, EN 301 958 DVB-RCT standard, 2003Barratt, K.A., Coulton, P., Honary, B., Defining performance limits for turbo-code assisted synchronization in DVB-S systems (2001) Transaction on Broadcasting, 47, pp. 348-356. , Dec, pagesPyndiah, R.M., Near-optimum decoding of product codes: Block turbo codes (1998) IEEE Trans. Commun, 46, pp. 1003-1010. , AugNickl, H., Hagenauer, J., Burkert, F., Approaching Shannon's Capacity Limit by 0.2 dB Using Simple Hamming Codes (1997) IEEE Communication Letters, 15, pp. 130-132. , SeptemberChen, Y., Parhi, K.K., Parallel decoding of interleaved single parity check turbo product codes, Signal Processing Systems, 2002. (SIPS '02) (2002) IEEE Workshop on, 16-18, pp. 27-32. , OctGuimarães, D.A., Portugueis, J., A Class of Product Codes and Its Interative (Turbo) decoding (2003) Proceding of the 3 rd International Symposium on Turbo Codes &ampRelated Topics, pp. 431-434. , Brest, France, Sep. 1-5Cuevas, J., Adde, P., Kerouedan, S., Pyndiah, R., New architecture for high data rate turbo decoding of product codes (2002) Global Telecommunications Conference, GLOBECOM '02, 2, pp. 1363-1367. , IEEE, 17-21 NovArgon, C., McLaughlin, S.W., Efficient decoding of turbo product codes (2001) Proc. 39th Annual Allerton Conference on Communications, Control, and Computing, , Monticello, IL, OctMoon, J., Li, Y., On reduced-complexity soft demapping in MIMO systems with spatial multiplexing (2005) IEEE International Conference on Communications ICC, 4, pp. 2302-2307. , 16-20 MayHokfelt, J., Edfors, O., Maseng, T., Interleaver design for turbo codes based on the performance of iterative decoding (1999) IEEE International Conference on Communications, 1, pp. 93-97. , 6-10 Jun

Growth Functions and Automatic Groups

In this paper we study growth functions of automatic and hyperbolic groups. In addition to standard growth functions, we also want to count the number of finite graphs isomorphic to a given finite graph in the ball of radius n around the identity element in the Cayley graph. This topic was introduced to us by K. Saito [1991]. We report on fast methods to compute the growth function once we know the automatic structure. We prove that for a geodesic automatic structure, the growth function for any fixed finite connected graph is a rational function. For a word-hyperbolic group, we show that one can choose the denominator of the rational function independently of the finite graph

Improving Dvb-t For Brazilian Environments

In this paper the improvement in the performance obtained by a Time Interleaving applied to DVB-T scheme are analyzed in impulsive noise environments. The performance is evaluated in terms of bit error rate probability for 0ms, 100ms and 200ms of time interleaving length. The results are compared with the standard DVB-T (Digital Video Broadcasting - Terrestrial) evaluated on Impulsive Noise channel and Multipath combined with impulsive noise channel. Simulation results shows that employing Time Interleaving only with 100ms the overall system performance can improve significantly. These results are obtained applying an appropriate interleaving after the Mapper of DVB-T system. © 2006 IEEE.376380ANATEL SP, www.anatel.gov.br (2000) Digital Television Systems - Brazilian testes - Final Report, , SET/ABERT Part 1, MarchANATEL SP, www.anatel.gov.br (2000) Digital Television Systems - Brazilian testes - Final Report, , SET/ABERT Part 2, MayNikookar, H., Nathoeni, D., Performance evaluation of OFDM transmission over impulsive noisy channels (2002) 13 th IEEE International Symposium on Personal, Indoor and Mobile Radio Communication, 15-18, 2, pp. 550-554. , Pages, SeptHazmi, A., Rinne, J., Kuusisto, T., Renfors, M., Performance evaluation of symbol synchronization in OFDM systems over impulsive noisy channels (2004) Vehicular Technology Conference, , SpringHazmi, A., Rinne, J., Kuusisto, T., Renfors, M., An enhanced impulsive burst cancellation method using pilots and soft bits in OFDM based systems (2004) IEEE 5 th Worshop on Signal Processing Advances in Wireless Communications, pp. 373-376. , Pages, 11-14 JulyZhidkov, S.V., Impulsive noise suppression in OFDM-based communication systems (2003) IEEE Transaction on Consumer Electronics, 49 (4), pp. 944-948. , Pages, NovZhidkov, S.V., (2006) Performance analysis and optimization of OFDM receiver with blanking nonlinearity in impulsive noise environment, 55 (1), pp. 234-242. , Jan, PagesAbdelkefi, F., Duhamel, P., Alberge, F., Impulsive noise cancellation in multicarrier transmission (2005) IEEE Transaction on Communication, 53 (1), pp. 94-106. , Pages, JanAndrews, K.S.W., Heegard, C., Kozen, D., A theory of interleavers, Techical Report, , TR97-1634, Departmnet of Computer Science, June 1997Channel coding, frame structure and modulation scheme for terrestrial integrate service digital broadcasting (ISDB-T) (1999), ITU-R WP 11A/59, ITU-R WP 11A/59-E, May 17Dolinar, S., Divsalar, D., Pollara, F., Code performance as a function of block size TMO Progress Report, , 42-133, JPL, May 1998Digital Video Broadcasting (DVB) (1997) Framing structure, channel coding and modulation for digital Terrestrial television (DVB-T), , ETSI European Telecommunications Standards Institute, MarchG. Bedicks, C. E. Dantas, F. Sukys, F. Yamada, L. T. M. Raunheitte, C. Akamine, Digital Signal Disturbed by Impulsive Noise 53th Annual IEEE Broadcast Symposium, Washington D.C. USA, 2003Lago-Fernández, J., Salter, J., Modelling impulsive interference in DVB-T - Statistical analysis, test waveforms and receiver performance (2004) BBC EBU Technical Review, , Jul

We measured and have expanded the space for more services in digital television

Digital TV stations transmissions can be configured so that the useful bit rate can accommodate a variable amount of information. We observed that the ISDB-Tb (Integrated Services Digital broadcasting - Terrestrial, version B) bit rate is not fully utilized by the broadcasters. Hence, services can be added beyond to the content of television without this being hindered2106671CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPnão temnão temnão te

A novel UWB antenna for a broadcasting television system

An ultra-wideband (UWB) discone antenna with an omnidirectional radiation pattern is proposed in order to be used in a broadcasting television system. It is an ultra-wideband antenna with an omnidirectional radiation pattern, using a single antenna to receive TV signals from several transmitting stations across various geographic locations. The UWB antenna proposed in this study covers a frequency range of 0.32-1.65 GHz with a gain of 1.7 dB. It operates in both conditions: indoor and outdoor310616