Lossless Transfer Research Articles

Increased Value of Video Assets: New Technologies for the Automatic Transfer and Digital Preservation of Analog Videocassettes

Millions of videocassettes are still stored on shelves, carrying valuable content waiting to be transferred into files before decomposing. Time is running short: not only does tape stock decay, but videotape recorder (VTR) availability becomes critical, and VTR service experts are becoming rare. As it is the final transfer, a technology for highly automated large-scale and lossless transfer that recovers and retains the original signal on tape is required. Direct tape transfer is a new technology that directly converts the off-tape signal from analog videotapes into digital files without passing through conventional playback circuits and its quality-degrading multiple analog-to-digital and digital-to-analog conversions of standard video playback equipment. By digitizing the radio frequency (RF) tape signal directly, all subsequent signal processes can be done by software with a much higher resolution than any that conventional VTR allows. Intelligent signal regeneration by smart dropout prevention and digital concealment algorithms allows signal recovery far beyond the possibilities of traditional dropout compensation circuitry. The paper explains the technical details of direct tape transfer technology, which was developed in a joint research project by the Fraunhofer Institute for Integrated Circuits IIS and Cube-Tec International GmbH.

Design of an Image Transfer System Based on the USB Interface

To realize images high speed and real-time transfer, the high speed USB2.0 interface which is based on TMS320DM642’sHPI and the CY7C68013A’sGPIF was designed. The projects of the hardware interface, firmware and application program were also presented. The interface implements the Bulk transfer mode, which makes the throughput meet requirement. The system makes the lossless transfer of the images possible, write speed of which is up to 30.7MB/s and read speed is up to 25.6MB/s. The result shows the design can meet powerful data transfer requirements.

A Minimal State Map for Strictly Lossless Positive Real Behaviors

In this paper, behaviors with equal input and output cardinalities and with lossless positive real transfer functions corresponding to certain input-output partitions are considered. Based on Cauer synthesis method, an algorithm to obtain a minimal state map of such behaviors starting from an observable image representation is given. This algorithm makes use of polynomial algebraic methods to arrive at a minimal state map. It is shown that the algorithm has application in synthesis and analysis of lossless electrical networks.

Study of radiofrequency radiation by means of optical effect of electromagnetically induced transparency

We propose a method of all-optical investigation of radiofrequency (RF) radiation based on the coherent effect of electromagnetically induced transparency (EIT). It is shown that if the atomic coherence is perturbed by an RF field, the shape of probe pulse propagating in a three-level Λ-type atomic medium under EIT conditions is modified correspondingly to the temporal structure of the RF pulse. The effect is sensitive to the parameters of the pulse which enables measuring the intensity and the spectrum of the RF pulse. The method can be used for storage and lossless transfer of RF information over long distances using optical pulses.

On lossless negative imaginary systems

The paper is concerned with the notion of lossless negative imaginary systems and their stabilization using strictly negative imaginary controllers through positive feedback. Firstly, the concept of lossless negative imaginary transfer functions is introduced and some properties of such transfer functions are studied. Secondly, a Lossless Negative Imaginary Lemma is given which establishes conditions on matrices appearing in a minimal state-space realization that are necessary and sufficient for a transfer function to be lossless negative imaginary. Thirdly, a necessary and sufficient condition is provided for the stabilization of a lossless negative imaginary system by a strictly negative imaginary controller. Finally, a flexible structure example is presented to illustrate the theory.

New Isolation Optimization Method of RF MEMS Capacitive Switches

A new isolation optimization method of radio frequency (RF) microelectromechanical systems (MEMS) capacitive switches is carried out in this paper. We simplified the coplanar waveguide and the top movable electrode as two-port network. The existence of the maximum isolation of single switch is proved theoretically based on circuit model and S-parameters model. The isolation of the distributed switches with lossless transfer lines, which is the function of the transfer lines length and the impedance of metal beams, is described by mathematic expressions and simulated in a numerical method. We find that the isolation varies periodically with θ and f, which are the electrical length between metal beams of the distributed switches and the signal frequency. It achieves the maximum value 83dB at θ=π/2 for 2-beams switch. However, different from single beam switches, the distributed switches maximum isolation is near but not precisely at the resonance frequency f0. The bandwidth of RF signal can be widened to about 200% for 5-beams switch by using the proposed design method. The results will be useful for Resistance-Inductance- Capacitance parameters optimization of RF MEMS Capacitive switches.

Coupling matrix synthesis of dissipative microwave filters

This study reviews the coupling matrix synthesis of dissipative microwave filters. It compares it to the synthesis of lossless transfer functions and shows that by correctly interpreting the mathematical operations in the lossless case, that is especially the matrix product of vectors and matrices, the same procedure can be adopted for the case including losses. Beyond this, necessary and sufficient conditions are provided guaranteeing that a proper coupling matrix, that is which is symmetric, is obtained at the end. Two examples show the application of the procedure and demonstrate that the correct filter transfer functions are indeed obtained.

Excess-noise-free recording and uploading of nonclassical states to continuous-variable quantum memory

A deterministic excess-noise-free recording of unknown quantum states to continuous-variable quantum atomic memory is proposed. To reach this, the memory experiment is extended by the presqueezing of the recorded state of light and deterministic squeezing post-correction of the recorded state. To upload highly nonclassical resources to the memory, such as single-photon state or superposition of coherent states, a probabilistic method is suggested. With the help of presqueezing of the resource state of light and probabilistic squeezing post-correction, this probabilistic upload approaches a lossless transfer of these highly nonclassical states into the quantum memory. Without the squeezing post-correction, the highly nonclassical state can still be probabilistically uploaded in the limit of a weak light-atom coupling.

Canonical lossless state-space systems: Staircase forms and the Schur algorithm

A new finite atlas of overlapping balanced canonical forms for multivariate discrete-time lossless systems is presented. The canonical forms have the property that the controllability matrix is positive upper triangular up to a suitable permutation of its columns. This is a generalization of a similar balanced canonical form for continuous-time lossless systems. It is shown that this atlas is in fact a finite sub-atlas of the infinite atlas of overlapping balanced canonical forms for lossless systems that is associated with the tangential Schur algorithm; such canonical forms satisfy certain interpolation conditions on a corresponding sequence of lossless transfer matrices. The connection between these balanced canonical forms for lossless systems and the tangential Schur algorithm for lossless systems is a generalization of the same connection in the SISO case that was noted before. The results are directly applicable to obtain a finite sub-atlas of multivariate input-normal canonical forms for stable linear systems of given fixed order, which is minimal in the sense that no chart can be left out of the atlas without losing the property that the atlas covers the manifold.

A Bandwidth Monitoring Mechanism Enhancing SNMP to Record Timed Resource Reservations

The efficient use of resources and the lossless transfer of data bursts in future optical networks requires the accurate knowledge of the available bandwidth for each network link. Such information is important in monitoring congestions and can be used by appropriate load balancing and congestion avoidance mechanisms. In this paper we propose a mechanism for monitoring and subsequently managing bandwidth resources, using the Simple Network Management Protocol (SNMP). In the proposed mechanism, link bandwidth availability is not a scalar parameter, but a function of time that records the future utilization of the link. For every output port, each agent-node maintains a simple data structure in the form of a table that records the utilization profile of that outgoing link. With the addition of new objects in the Management Information Base (MIB) of each agent-node and proper synchronization, SNMP can be used to update and retrieve the reservations made on the links in order to obtain an instant picture of the network traffic situation.

Interaction of exchange and differential relaxation in the saturation recovery behavior of the binary spin-bath model for magnetization transfer

Most closed-form analytical solutions of the binary spin-bath are difficult to interpret in terms of underlying physics. The key notions are the presence of a kinetic and a thermal equilibrium and that the time course of saturation recovery under conditions of fast exchange can be understood as conjoint relaxation and lossless transfer. By introducing a suitable parameter, it is shown how exchange and differential relaxation counteract each other: the amount of transferred saturation (transfer term) is altered and the kinetic equilibrium appears slightly disturbed (difference term). Although the factorization formally represents the general solution of saturation recovery in the binary spin-bath, this interpretation applies only to the case of fast exchange and slow relaxation. By calculating the set of parameters for a wide range of hypothetical relaxation rates, it was shown that the difference term is crucial to describe the transition to the slow-exchange limit. The transfer term vanishes as the two pools appear decoupled in this approximation. © 2006 Wiley Periodicals, Inc. Concepts Magn Reson Part A 28A: 291–298, 2006.

Canonical Lossless State-Space Systems: Staircase Forms and the Schur Algorithm

A new finite atlas of overlapping balanced canonical forms for multivariate discrete-time lossless systems is presented. The canonical forms have the property that the controllability matrix is positive upper triangular up to a suitable permutation of its columns. This is a generalization of a similar balanced canonical form for continuous-time lossless systems. It is shown that this atlas is in fact a sub-atlas of the infinite atlas of overlapping balanced canonical forms for lossless systems that is associated with the tangential Schur algorithm; such canonical forms satisfy certain interpolation conditions on a corresponding sequence of lossless transfer matrices. The connection between these balanced canonical forms for lossless systems and the tangential Schur algorithm for lossless systems is a generalization of the same connection in the SISO case that was noted before. The results are directly applicable to obtain a finite atlas of multivariate input-normal canonical forms for stable linear systems of given fixed order, which is minimal in the sense that no chart can be left out of the atlas without losing the property that the atlas covers the manifold of stable linear systems of fixed given order.

Synthesis of predistorted reflection‐mode hybrid prototype networks with symmetrical and asymmetrical characteristics

AbstractA new technique for predistorting filter transfer functions to compensate for the dissipative losses present in the resonator elements is introduced. The method is based on the formation of two admittances from lossless transfer functions. Each admittance is then individually predistorted and connected to a 3‐dB hybrid coupler. A simulated numerical example demonstrates that the method is capable of designing network prototypes with a combined predistorted reflection and transmission functions. Tables of prototype element values for elliptic lowpass/highpass functions are also provided. Copyright © 2001 John Wiley & Sons, Ltd.

Parametrized Family of 2-D Non-factorable FIR Lossless Systems and Gröbner Bases

The factorability of one-dimensional (1-D) FIR lossless transfer matrices [1] in terms of Givens rotations produces the parameters that can be used for an optimal design of filter banks with prespecified filtering characteristics. Two dimensional (2-D) FIR lossless systems behave quite differently, however. Venkataraman-Levy [2] and Basu-Choi-Chiang [3] have constructed 2-D FIR paraunitary matrices of McMillan degrees (2,2) that are not factorable. Because of the state-space realization used in the construction, they are floating-point approximations, and they do not produce explicit parametrizations that can be used for optimal design process. In this paper, we formulate the lossless condition and nonfactorability condition of a 2-D FIR paraunitary matrix using multivariate polynomials in the coefficients. The resulting polynomial system can be explicitly solved with Grobner bases. By studying the polynomial system, we obtain a continuous one parameter family of 2-D 2×2 non-factorable paraunitary matrices. As an example, we get a closed-form expression for a 2-D 2×2 paraunitary matrix that is not factorable into rotations and delays.

State space representations of 2-D FIR lossless transfer matrices

This paper examines the properties of state-space realizations of square 2-D FIR lossless transfer matrices. Such matrices have found applications for the design of 2-D orthogonal perfect reconstruction filter banks. It is shown that 2-D FIR lossless matrices admit a minimal first-level realization with respect to one transform variable, where the dynamics are FIR and lossless in the other variable. This result is then employed to prove that 2-D FIR lossless transfer matrices admit a minimal 2-D Roesser realization whose dynamics are parametrized by a single constant orthonormal matrix, which satisfies constraints ensuring that the resulting transfer matrix is FIR. This parametrization is used to compute the number of degrees of freedom available for the synthesis of a 2-D FIR lossless transfer matrix of fixed McMillan degree in each variable. It is also shown that 2-D lossless FIR transfer matrices cannot necessarily be represented as a product of lossless FIR factors of lower degree, and conditions for the existence of such factorizations are given.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

State-space approach to factorization of lossless transfer functions and structured matrices

The concept of J -lossless triangular state-space models is reviewed, and its relation to Lyapunov equations and to matrices with a displacement structure is characterized in detail. A new recursive procedure for cascade synthesis of such state-space models is introduced. In contrast to previous state-space-based techniques for cascade decomposition (factorization) of J -lossless transfer functions, which require conversion of a given state-space representation into an equivalent balanced form , our new procedure recursively determines a sequence of unbalanced J -lossless state-space models. The cascade decomposition of a given J -lossless transfer function obtained by the new procedure is the same as the one obtained by the previous techniques, but the attendant computational requirements are significantly reduced. Furthermore, the final computational formulation of our procedure subsumes many previous methods for efficient triangular factorization of structured matrices—the so-called “generalized Schur” or “generalized fast Cholesky” algorithms.

Rational subspace estimation using adaptive lossless filters

Rational models have been studied as a tractable attempt to account for frequency dependencies using a finite parameter description. In this context, the following problem is addressed: Given time-domain measurements, estimate rational orthonormal spanning vectors for the signal and noise subspaces. It is shown that the problem can be rephrased as adapting a lossless transfer matrix so as to maximize the power split between two sets of output bins. An efficient and numerically robust adaptive filtering algorithm is derived for lossless multivariable lattice filters, and the system can be programmed in real time using CORDIC processors. The adaptive filter equations are consistent with the proper subspace identification if the subspace filter satisfies a sufficient order condition. In under-modeled scenarios the stable stationary points are characterized by a minimized Rayleigh quotient which leads to good subspace fits. The proposed adaptive filter makes real-time rational subspace estimation an accessible alternative to computationally expensive offline techniques.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

On coefficient-quantization and computational roundoff effects in lossless multirate filter banks

It is shown that FIR lossless transfer matrices in multirate analysis/synthesis systems having the perfect reconstruction property can be implemented such that the lossless property (and hence perfect reconstruction) can be retained regardless of coefficient quantization. Such a result was previously shown to be true only for two-channel filter banks. A noise gain result is presented for lossless systems which finds application in analyzing roundoff noise in multirate filter banks. >

On factorization of a subclass of 2-D digital FIR lossless matrices for 2-D QMF bank applications

The role of one-dimensional (1-D) digital finite impulse response (FIR) lossless matrices in the design of FIR perfect reconstruction quadrature mirror filter (QMF) banks has been explored previously. Structures which can realize the complete family of FIR lossless transfer matrices, have also been developed, with QMF application in mind. For the case of 2-D QMF banks, the same concept of lossless polyphase matrix has been used to obtain perfect reconstruction. However, the problem of finding a structure to cover all 2-D FIR lossless matrices of a given degree has not been solved. Progress in this direction is reported. A structure which completely covers a well-defined subclass of 2-D digital FIR lossless matrices is obtained. >

Minimal structures for the implementation of digital rational lossless systems

Digital lossless transfer matrices and vectors (power-complementary vectors) are discussed for applications in digital filter bank systems, both single rate and multirate. Two structures for the implementation of rational lossless systems are presented. The first structure represents a characterization of single-input, multioutput lossless systems in terms of complex planar rotations, whereas the second structure offers a representation of M-input, M-output lossless systems in terms of unit-norm vectors. This property makes the second structure desirable in applications that involve optimization of the parameters. Modifications of the second structure for implementing single-input, multioutput, and lossless bounded real (LBR) systems are also included. The main importance of the structures is that they are completely general, i.e. they span the entire set of M*1 and M*M lossless systems. This is demonstrated by showing that any such system can be synthesized using these structures. The structures are also minimal in the sense that they use the smallest number of scalar delays and parameters to implement a lossless system of given degree and dimensions. A design example to demonstrate the main results is included. >