Gold Code
A Gold code, also known as Gold sequence, is a type of binary sequence, used in telecommunications (CDMA) and satellite navigation ( GPS). Gold codes are named after Robert Gold. Gold codes have bounded small cross-correlations within a set, which is useful when multiple devices are broadcasting in the same frequency range. A set of Gold code sequences consists of 2''n'' + 1 sequences each one with a period of 2''n'' − 1. A set of Gold codes can be generated with the following steps. Pick two maximum length sequences of the same length 2''n'' − 1 such that their absolute cross-correlation is less than or equal to 2(''n''+2)/2, where ''n'' is the size of the linear-feedback shift register used to generate the maximum length sequence. The set of the 2''n'' − 1 exclusive-ors of the two sequences in their various phases (i.e. translated into all relative positions) together with the two maximum length sequences form a set of 2''n'' + 1 Gold code sequences. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Sequence
In mathematics, a sequence is an enumerated collection of objects in which repetitions are allowed and order matters. Like a set, it contains members (also called ''elements'', or ''terms''). The number of elements (possibly infinite) is called the ''length'' of the sequence. Unlike a set, the same elements can appear multiple times at different positions in a sequence, and unlike a set, the order does matter. Formally, a sequence can be defined as a function from natural numbers (the positions of elements in the sequence) to the elements at each position. The notion of a sequence can be generalized to an indexed family, defined as a function from an ''arbitrary'' index set. For example, (M, A, R, Y) is a sequence of letters with the letter "M" first and "Y" last. This sequence differs from (A, R, M, Y). Also, the sequence (1, 1, 2, 3, 5, 8), which contains the number 1 at two different positions, is a valid sequence. Sequences can be '' finite'', as in these examples, or '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Kasami Code
Kasami sequences are binary sequences of length where is an even integer. Kasami sequences have good cross-correlation values approaching the Welch lower bound. There are two classes of Kasami sequences—the small set and the large set. Kasami Set The process of generating a Kasami sequence is initiated by generating a maximum length sequence , where . Maximum length sequences are periodic sequences with a period of exactly . Next, a secondary sequence is derived from the initial sequence via cyclic decimation sampling as , where . Modified sequences are then formed by adding and cyclically time shifted versions of using modulo-two arithmetic, which is also termed the exclusive or Exclusive or, exclusive disjunction, exclusive alternation, logical non-equivalence, or logical inequality is a logical operator whose negation is the logical biconditional. With two inputs, XOR is true if and only if the inputs differ (on ... (xor) operation. Computing modified sequences ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Brandenburg University Of Technology
The Brandenburg University of Technology Cottbus–Senftenberg (, BTU) was founded in 1991 and is a technical university in Brandenburg, Germany with campuses in Cottbus and Senftenberg. The university has 185 professors, 640 additional academic staff and more than 7,000 students, of which 2,350 are of foreign origin from more than 100 nations. History The university was founded in 1954 as a school for construction engineering in the former East Germany, GDR. After German reunification, the school became a technical university and was later renamed Brandenburg Technical University in 1994. In the following years, the university underwent major construction efforts and the number of students continued to grow. In February 2013 the Landtag of Brandenburg decided to merge the BTU and the Hochschule Lausitz on 1 July 2013 to create the new university Brandenburgische Technische Universität Cottbus-Senftenberg (abbreviated BTU). Today, the university has 7,280 students, 2,190 of wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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The Institution Of Electrical Engineers
The Institution of Electrical Engineers (IEE) was a British professional organisation of electronics, electrical, manufacturing, and information technology professionals, especially electrical engineers. It began in 1871 as the Society of Telegraph Engineers. In 2006, it merged with the Institution of Incorporated Engineers and the new organisation is Institution of Engineering and Technology (IET). Notable past presidents have included Lord Kelvin (1889), Sir Joseph Swan (1898) and Sebastian de Ferranti (1910–11). Notable chairmen include John M. M. Munro (1910–11). History The IEE was founded in 1871 as the Society of Telegraph Engineers, changed its name in 1880 to the Society of Telegraph Engineers and Electricians and changed to the Institution of Electrical Engineers in 1888. It was Incorporated by a Royal Charter in 1921. In 1988 the Institution of Electrical Engineers (IEE) merged with the Institution of Electronic and Radio Engineers (IERE), originally the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Springer Verlag
Springer Science+Business Media, commonly known as Springer, is a German multinational publishing company of books, e-books and peer-reviewed journals in science, humanities, technical and medical (STM) publishing. Originally founded in 1842 in Berlin, it expanded internationally in the 1960s, and through mergers in the 1990s and a sale to venture capitalists it fused with Wolters Kluwer and eventually became part of Springer Nature in 2015. Springer has major offices in Berlin, Heidelberg, Dordrecht, and New York City. History Julius Springer founded Springer-Verlag in Berlin in 1842 and his son Ferdinand Springer grew it from a small firm of 4 employees into Germany's then second-largest academic publisher with 65 staff in 1872.Chronology ". Springer Science+Business Media. In 1964, Springer expanded its business internationally, op ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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IEEE Transactions On Information Theory
''IEEE Transactions on Information Theory'' is a monthly peer-reviewed scientific journal published by the IEEE Information Theory Society. It covers information theory and the mathematics of communications. It was established in 1953 as ''IRE Transactions on Information Theory''. The editor-in-chief is Venugopal V. Veeravalli (University of Illinois Urbana-Champaign). As of 2007, the journal allows the posting of preprints on arXiv. According to Jack van Lint, it is the leading research journal in the whole field of coding theory. A 2006 study using the PageRank network analysis algorithm found that, among hundreds of computer science-related journals, ''IEEE Transactions on Information Theory'' had the highest ranking and was thus deemed the most prestigious. ''ACM Computing Surveys'', with the highest impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact factor values are consid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Xilinx
Xilinx, Inc. ( ) was an American technology and semiconductor company that primarily supplied programmable logic devices. The company is renowned for inventing the first commercially viable field-programmable gate array (FPGA). It also pioneered the first fabless manufacturing model.Jonathan Cassell, iSuppli.A Forgettable Year for Memory Chip Makers: iSuppli releases preliminary 2008 semiconductor rankings." December 1, 2008. Retrieved January 15, 2009.John Edwards, EDN." June 1, 2006. Retrieved January 15, 2009. Xilinx was co-founded by Ross Freeman, Bernard Vonderschmitt, and James V. Barnett II, James V Barnett II in 1984. The company went public on the Nasdaq in 1990. In October 2020, AMD announced its acquisition of Xilinx, which was completed on February 14, 2022, through an all-stock transaction valued at approximately $60 billion. Xilinx remained a wholly owned subsidiary of AMD until the brand was phased out in June 2023, with Xilinx's product lines now branded under AMD. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Space Network
Space Network (SN) is a NASA program that combines space and ground elements to support spacecraft communications in Earth vicinity. The SN Project Office at Goddard Space Flight Center (GSFC) manages the SN, which consists of: * The geosynchronous Tracking and Data Relay Satellites (TDRS), * Supporting ground terminal systems, * The Bilateration Ranging and Transponder System (BRTS), * Merritt Island Launch Annex (MILA) relay, * Network Control Center Data System (NCCDS). Satellite generations Tracking and Data Relay Satellite (TDRS) currently consists of first-generation (F1–F7), and second-generation (F8–F10) satellites. The space segment of the SN consists of up to six operational relay satellites in geosynchronous orbit. These communications satellites are allocated longitudes for relaying forward and return service signals to and from customers, any entity with an Earth-orbiting satellite that has an agreement with SN to use its communications services, for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complementary Sequences
: ''For complementary sequences in biology, see complementarity (molecular biology). For integer sequences with complementary sets of members see Lambek–Moser theorem.'' In applied mathematics, complementary sequences (CS) are pairs of sequences with the useful property that their out-of-phase aperiodic autocorrelation coefficients sum to zero. Binary complementary sequences were first introduced by Marcel J. E. Golay in 1949. In 1961–1962 Golay gave several methods for constructing sequences of length 2''N'' and gave examples of complementary sequences of lengths 10 and 26. In 1974 R. J. Turyn gave a method for constructing sequences of length ''mn'' from sequences of lengths ''m'' and ''n'' which allows the construction of sequences of any length of the form 2''N''10''K''26''M''. Later the theory of complementary sequences was generalized by other authors to polyphase complementary sequences, multilevel complementary sequences, and arbitrary complex complementary sequences. C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Zadoff–Chu Sequence
A Zadoff–Chu (ZC) sequence is a complex-valued mathematical sequence which, when applied to a signal, gives rise to a new signal of constant amplitude. When cyclically shifted versions of a Zadoff–Chu sequence are imposed upon a signal the resulting set of signals detected at the receiver are uncorrelated with one another. Description Zadoff–Chu sequences exhibit the useful property that cyclically shifted versions of themselves are orthogonal to one another. A generated Zadoff–Chu sequence that has not been shifted is known as a ''root sequence''. The complex value at each position ''n'' of each root Zadoff–Chu sequence parametrised by ''u'' is given by : x_u(n)=\text\left(-j\frac\right), \, where : 0 \le n < N_\text, : and , : , : , : . Zadoff–Chu sequences are CAZAC sequences ( [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JPL Code
JPL sequences or JPL codes consist of two linear feedback shift registers (LFSRs) whose code sequence lengths ''L''a and ''L''b must be prime (relatively prime). In this case the code sequence length of the generated overall sequence ''L''c is equal to: :L_c = L_a \cdot L_b = (2^n - 1)(2^m - 1) It is also possible for more than two LFSRs to be interconnected through multiple XORs at the output for as long as all code sequence lengths of the individual LFSR are relatively prime to one another. JPL sequences were originally developed in the Jet Propulsion Labs, from which the name for these code sequences is derived. Areas of application include distance measurements utilizing spread spectrum signals for satellites and in space technology. They are also utilized in the more precise military P/Y code used in the Global Positioning System The Global Positioning System (GPS) is a satellite-based hyperbolic navigation system owned by the United States Space Force and oper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Telecommunications
Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information over a distance using electronic means, typically through cables, radio waves, or other communication technologies. These means of transmission may be divided into communication channels for multiplexing, allowing for a single medium to transmit several concurrent Session (computer science), communication sessions. Long-distance technologies invented during the 20th and 21st centuries generally use electric power, and include the electrical telegraph, telegraph, telephone, television, and radio. Early telecommunication networks used metal wires as the medium for transmitting signals. These networks were used for telegraphy and telephony for many decades. In the first decade of the 20th century, a revolution in wireless communication began with breakthroughs including those made in radio communications by Guglielmo Marconi, who won the 1909 Nobel Prize in Physics. Othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |