Jonas Lundstedt - Academia.edu (original) (raw)

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Papers by Jonas Lundstedt

Proceedings of ISSE'95 - International Symposium on Signals, Systems and Electronics

In this paper the applicability of the compact Green functions technique in the problems of signa... more In this paper the applicability of the compact Green functions technique in the problems of signal restoration and device characterization is discussed. It is shown that the compact Green functions, in a straightforward way, can be used to restore the incident signal from the distorted signal which is received at the other end of the line. Further, an exact method to reconstruct two of the electrical parameters of a nonuniform transmission line from the transient response is presented. This method may be used to characterize a microwave device in terms of transmission line parameters.

2017 IEEE International Conference on Communications Workshops (ICC Workshops), 2017

This paper presents a novel network slicing management and orchestration architectural framework.... more This paper presents a novel network slicing management and orchestration architectural framework. A brief description of business scenarios and potential customers of network slicing is provided, illustrating the need for ordering network services with very different requirements. Based on specific customer goals (of ordering and building an end-to-end network slice instance) and other requirements gathered from industry and standardization associations, a solution is proposed enabling the automation of endto-end network slice management and orchestration in multiple resource domains. This architecture distinguishes between two main design time and runtime components: Network Slice Design and Multi-Domain Orchestrator, belonging to different competence service areas with different players in these domains, and proposes the required interfaces and data structures between these components.

Mathematics and Computers in Simulation, 1999

Inverse problems are considered for the linear one-way one-dimensional wave equation or transport... more Inverse problems are considered for the linear one-way one-dimensional wave equation or transport equation. In particular the wave speed reconstruction problem for a medium is discussed. Inverse problems for non-stationary, but also non-dispersive, media are examined; this means problems for which the slab medium parameters are both spatially and temporally varying are considered. Both theoretical and numerical results are given for the methods presented. Theoretical results obtained for this equation can be generalised to second order equations.

Journal of Electromagnetic Waves and Applications, 1996

We quantify the mean asymmetry of 54 face-on, early type disk galaxies (S0 to Sab) using the ampl... more We quantify the mean asymmetry of 54 face-on, early type disk galaxies (S0 to Sab) using the amplitude of the m = 1 azimuthal Fourier component of the R-band surface brightness. We find that the median lopsidedness, A 1 /A 0 , of our sample is 0.11 and that the most lopsided 20% of our galaxies have A 1 /A 0 ≥ 0.19. Asymmetries in early type disks appear to be of similar frequency and strength as in late type disk galaxies (Zaritsky and Rix 1997.) We have observed our early type disks in a bandpass (R-Band) in which the light is dominated by stars with ages greater than 10 9 yrs, and therefore are seeing azimuthal asymmetries in the stellar mass distribution. The similar degree of lopsidedness seen in disks of very different star formation rates indicates that the lopsidedness in all galactic disks is primarily due to azimuthal mass asymmetries. Hence, 20% of all disk galaxies (regardless of Hubble Type) have azimuthal asymmetries, A 1 /A 0 ≥ 0.19, in their stellar disk mass distribution, confirming lopsidedness as a dynamical phenomenon.

Journal of Electromagnetic Waves and Applications, 2003

ABSTRACT In this paper, we present two methods for the inverse problem ofreconstructing a paramet... more ABSTRACT In this paper, we present two methods for the inverse problem ofreconstructing a parameter profile ofa nonunif orm and dispersive transmission line — one frequency domain and one time domain method. Both methods are based on the wave splitting technique, but apart from that the methods are mathematically very different. The time domain analysis leads to hyperbolic partial differential equations and an inverse method based on solving implicit equations. The frequency domain analysis leads instead to Riccati differential equations and an inverse method based on optimization. The two methods are compared numerically by simulating a reconstruction ofa soil moisture profile along a flat band cable. A heuristic model ofthe dispersion characteristics ofa flat band cable in moist sand is derived. We also simulate the effect parasitic capacitances at the cable ends has on the reconstructions. The comparison shows that neither method outperforms the other. The time domain method is numerically much faster whereas the frequency domain method is much faster to implement. An important conclusion is also that it is crucial to model the connector parasitic capacitances correctly — especially ifthere are impedance mismatches at the connectors.

IEEE Transactions on Microwave Theory and Techniques, 1994

In the present paper, signal restoration after transmission through a nonuniform LCRG line is tre... more In the present paper, signal restoration after transmission through a nonuniform LCRG line is treated by means of a compact Green function approach. These Green functions are characteristic of the nonuniform line and independent of the incident signal. The compact Green functions map the signal which is received after transmission through a nonuniform LCRG line to split components of the

IEEE Transactions on Microwave Theory and Techniques, 1995

The well-known condition for distortionless signal propagation on a dissipative transmission line... more The well-known condition for distortionless signal propagation on a dissipative transmission line with constant impedance is generalized to the case of nonuniform impedance. The result is based on a time-domain wave-splitting formulation of the Telegraphist's equations. It is shown that an appropriate choice of the resistance and the conductance can eliminate the distortion caused by the varying characteristic impedance. A nonuniform transmission line that satisfies the given condition is distortionless in both directions, but reflectionless for signals propagating in one direction only. >

Inverse problems are considered for the linear one-way wave equation or transport equation. In pa... more Inverse problems are considered for the linear one-way wave equation or transport equation. In particular a number of inverse source reconstruction problems are considered. Problems which have both spatially and temporally varying coefficients are discussed. Both theoretical and numerical results are given for the methods examined. In particular it is shown that the source reconstruction is unique for the inverse problems discussed.

Ericsson review, 2005

... Outdoor cabinets The RBS 3106 outdoor cabinet has the same footprint as the GSM 2106 and WCDM... more ... Outdoor cabinets The RBS 3106 outdoor cabinet has the same footprint as the GSM 2106 and WCDMA RBS 3101. ... Ericsson Review No. 2, 2005 79 has the potential to improve cost-effective-ness in the radio access network. ... TX chain linearity; and fast congestion control. ...