theory of spread spectrum

Ngày tải lên: 20/01/2014, 06:20

Ngày tải lên: 27/06/2014, 09:20

Ngày tải lên: 21/06/2014, 19:20

... dùng cho thông tin vệ tinh trong CDMA. Trải phổ nhảy tần Frequency Hopping Spread Spectrum  Frequency Hopping Spread Spectrum (FHSS)  Được phát minh bởi nữ diễn viên Hollywood Hedy Lamarr, ... thu và máy phát đều có bộ tạo mã PN gồm k chíp mã tương ứng với 1 từ tần số Direct Sequence Spread Spectrum Transmitter Vídụ CDMA Các ưu nhược điểm FHSS  Ưu điểm :  Giảm fading đa đường do ... phát hiện Nhảy tần nhanh (Fast FHSS) (M=4, k=2) Điều chế và giải điều chế Direct Sequence Spread Spectrum Transmitter Trải phổ nhảy tần  Dẫy PN dùng để điều khiển (xác định) mẫu nhảy. Tốc...

Ngày tải lên: 13/09/2012, 11:16

... 43 OFDM February 2005 Copyright 2005 All Rights Reserved 3 Spread Spectrum ● Spread spectrum is a communication technique that spreads a narrowband communication signal over a wide range of ... which employs OFDM in the 2.4 GHz range February 2005 Copyright 2005 All Rights Reserved 6 Spread Spectrum Use ● In the 1980s FCC implemented a set of rules making Spread Spectrum available ... the imaginary or quadrature axis of the complex plane. February 2005 Copyright 2005 All Rights Reserved 4 Narrowband vs Spread Spectrum Frequency Power Spread Spectrum (Low Peak Power) Narrowband (High...

Ngày tải lên: 13/09/2012, 11:16

... which are seen as a form of market imperfection. The mainstream theory of the firm evolved under the paradigm of the agency theory and the transaction costs theory as a theory of economic organization rather ... amendment of the existing theory of financial intermediation. The structure of this paper is as follows. First, we introduce the foundations of the modern literature of financial intermediation theory. ... review the doctrines of the theory of financial intermediation. 2 These are specifications, relevant to the financial services industry, of the agency theory, and the theory of imperfect or asymmetric...

Ngày tải lên: 24/10/2012, 09:11

... efficiently, the reputational capital of an agent must equal the present value of the stream of future profits, or franchise value, of her business. The concept of reputational capital is meaningful ... Structural implications of CTF Circuit theory of finance (CTF) bears important implications in terms of financial market structure, microeconomic imbalances, and the role of saving for economic ... on the basis of verifiable and tested information. Information providers might be either profit or non-profit outfits. Providers of customized information might operate for a profit and sell...

Ngày tải lên: 24/10/2012, 09:33

... domain, X(f )issimplyacopyofthe spectrum ˜ X(f) shifted to a center frequency of f =+f c and a mirror copy of ˜ X(f)shifted to a center frequency of f = −f c . The operation of modulation can be defined ... SummaryofAngleSpectrumConcepts 124 5.2 FadingRateVariance 127 5.2.1 DefinitionofaRateVariance 127 5.2.2 Fundamental Spectral Spread Theorem . . . 129 5.3 MultipathShapeFactors 130 5.3.1 DefinitionofShapeFactors ... ProperLimitingBehavior 117 4.B.4 PreservationoftheSecondMoment 117 5 The Angle Spectrum 118 5.1 AngleSpectrumConcepts 119 5.1.1 DefinitionoftheAngleSpectrum 119 5.1.2 MappingAnglestoWavenumbers...

Ngày tải lên: 20/11/2012, 11:36

... multi-carrier, spread spectrum and multi-carrier spread spectrum systems. We hope that this book will contribute to a better understanding of the principles of multi-carrier and spread spectrum and ... is essential for a better understanding of the idea behind the combination of OFDM with the spread spectrum technique, which is briefly introduced in the last part of this chapter. 1.1 Radio Channel ... 1.(1.28) −1 −0.5 0 0.5 1 Normalized frequency 10 0 −10 −20 −30 Power spectral density spectrum of 1st sub-channel OFDM spectrum Figure 1-5 OFDM spectrum with 16 sub-carriers Contents ix 4.3.8 Blind and Semi-Blind...

Ngày tải lên: 02/03/2013, 16:58

Ngày tải lên: 29/09/2013, 20:20

... behavior of the number of multiplications is also quadratic. Convolution algebras are derived from algebras of polynomials. Given a polynomial P (u) of degree D, one can define an algebra of dimension ... Introduction Complexity theory of computation attempts to determine how “inherently” difficult are certain tasks. For example, how inherently complex is the task of computing an inner product of two vectors of length ... original proof); the reference I like best is Adrian Albert’s book [1]. The theorem asserts that the tensor product of fields is isomorphic to a direct sum of fields, and the proof of the theorem...

Ngày tải lên: 25/10/2013, 02:15

... number of collisions per particle (a measure of time), given by τ ≡  t 0 T 1/2 (t  )  dt  . The use of this measure of time renders the equations of motion linear. The three eigenvalues of this ... of the linearised Boltzmann equation, at each order in the expansion. Since the solution of equations of the type of Eq. (12.22) is determined up to the addition of an arbitrary combination of ... sheared system is of a much higher granular temperature than that expected on the basis of steady-state solutions of the corresponding hydrodynamic equations. In this case the 208 Theory of rapid granular...

Ngày tải lên: 01/11/2013, 08:20

... into a theory of inventive problem solving which he named TRIZ. 3.0 TRIZ: The Theory of Inventive Problem Solving There are a number of laws in the theory of TRIZ. One of them is the Law of Increasing ... Xerox Corporation 7.0 TRIZ Software Because TRIZ is built on a database of hundreds of thousands of patents, principles, operators, contradictions, etc. use of software helps engineers with ... nonmoving object 3. Length of moving object 4. Length of nonmoving object 5. Area of moving object 6. Area of nonmoving object 7. Volume of moving object 8. Volume of nonmoving object 9. Speed...

Ngày tải lên: 10/12/2013, 03:15

... gr qrw h{lvw  Wkh sk|vlfdo phfkdqlvpv gulylqj wkh sureohp duh vr frpsolfdwhg wkdw wkh gluhfw fdofxodwlrq ri wkh sureohp lv qrw ihdvleoh  Wkhuh h{lvwv vrph edvlf lqghwhuplqdf| lq wkh sk|vlfdo...

Ngày tải lên: 12/12/2013, 04:15

... use of OVSF codes is thus a key factor in the high degree of service flexibility of the W- CDMA air interface. Let C N be a matrix of size NxN and denote the set of N binary spreading codes of ... requiring spread spectrum modulation: DSSS (Direct Sequence Spread Spectrum) and FHSS (Frequency Hopping Spread Spectrum) . Only the RF transmission has significant presence in the market. 1Mbps Spreading d t pn t DBPSK 11 ... Sint-Katelijne-Waver Belgium www.denayer.be Spread Spectrum (SS) applications ir. J. Meel jme@denayer.wenk.be Studiedag Spread Spectrum 6 okt. ’99 In the period of nov. 1997 - nov. 1999 a Spread Spectrum project was...

Ngày tải lên: 13/12/2013, 00:15

... EFFICIENCY OF CAPITAL 12. THE STATE OF LONG-TERM EXPECTATION 13. THE GENERAL THEORY OF THE RATE OF INTEREST 14. THE CLASSICAL THEORY OF THE RATE OF INTEREST o APPENDIX ON THE RATE OF INTEREST ... advantages of private and national thrift, the traditional attitude towards the rate of interest, the classical theory of unemployment, the quantity theory of money, the unqualified advantages of laissez-faire ... and of the trade cycle. Another feature, especially characteristic of this book, is the theory of the rate of interest. In recent times it has been held by many economists that the rate of current...

Ngày tải lên: 15/12/2013, 21:15

Ngày tải lên: 17/12/2013, 15:18

... gr qrw h{lvw  Wkh sk|vlfdo phfkdqlvpv gulylqj wkh sureohp duh vr frpsolfdwhg wkdw wkh gluhfw fdofxodwlrq ri wkh sureohp lv qrw ihdvleoh  Wkhuh h{lvwv vrph edvlf lqghwhuplqdf| lq wkh sk|vlfdo...

Ngày tải lên: 20/12/2013, 19:15

Ngày tải lên: 23/12/2013, 02:19

Ngày tải lên: 30/12/2013, 10:45