| 1. |
- Höök, Anders, 1962, et al.
(författare)
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Soliton instabilities and pulse compression in minimum dispersion fibers
- 1994
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Ingår i: IEEE Journal of Quantum Electronics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9197 .- 1558-1713. ; 30:8, s. 1831-1841
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Tidskriftsartikel (refereegranskat)abstract
- A new stability of ultrashort pulses in optical fibers is demonstrated which, together with a recently discovered modulation instability, is shown to deteriorate a pulse compression mechanism. The pulse compression is analyzed in detail by means of a perturbation technique.
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| 2. |
- Karlsson, Magnus, 1967, et al.
(författare)
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Soliton-like pulses governed by fourth order dispersion in optical fibers
- 1994
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Ingår i: Optics Communications. - : Elsevier BV. - 0030-4018. ; 104:4-6, s. 303-307
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Tidskriftsartikel (refereegranskat)abstract
- The properties of pulse propagation in a nonlinear fiber including negative fourth order dispersion added to anomalous second order dispersion are analyzed numerically and analytically. An exact localized analytical solution is presented, and using an approximate variational method, an entire family of stationary approximate solutions is also obtained. These solutions are found to be in excellent agreement with numerical simulations.
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| 3. |
- Ottersten, Björn, 1961-, et al.
(författare)
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Robust Source Localization Based on Local Array Response Modeling
- 1992
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Ingår i: Proceedings of the 1992 IEEE International Conference on Acoustics, Speech and Signal Processing. - Linköping : IEEE. - 0780305329 ; , s. 441-444 vol.2
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Konferensbidrag (refereegranskat)abstract
- Many practical applications of signal processing require accurate determination of signal parameters from sensor array measurements. Most estimation techniques are sensitive to errors in the array response model. Thus, reliable array calibration schemes are of great importance. A paradigm for generating an array model from noise corrupted calibration vectors is developed. The key idea is to use a local parametric model of the sensor responses. The potential improvement using the suggested scheme is demonstrated on real data collected from a full-scale hydroacoustic array.
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| 4. |
- Smeets, Ben
(författare)
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Bounds on the probability of deception in multiple authentication
- 1994
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Ingår i: IEEE Transactions on Information Theory. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9448. ; 40:5, s. 1586-1591
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Tidskriftsartikel (refereegranskat)abstract
- The frequently assumed "freshness" constraint on the source states in multiple authentication schemes is not necessary if one allows the encoding rule to change between subsequent transmissions. In the paper it is shown that the main existing lower bounds on the probabilities of successful attack on multiple authentication schemes also hold for this new setup. Furthermore, Stinson's (1988) bound for the substitution attack is strengthened
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| 5. |
- Viberg, Mats, et al.
(författare)
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Source Localization in the Presence of Model Uncertainties
- 1992
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Ingår i: Proceedings of the 2nd Workshop on Adaptive Algorithms in Communications.
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Konferensbidrag (refereegranskat)abstract
- In many signal processing applications high accuracy signal parameter estimation from sensor array data is a significant problem. Much of the recent work in array processing has focused on methods for high-resolution location estimation. Model based estimation techniques requre accurate knowledge of the so-called array manifold. In practise, the array response is often determined by measuring the array response when only one emitter is radiating and the signal parameters of which are allowed to vary in a known way. This paper addresses some of the practical issues that arise in generating the so-called array manifold from a finite collection of caibration vectors. For high-resolution signal parameter estimation techniques to be successful, the interpolated array manifold has to satisfy certain smoothness conditions. A paradigm for generating an array model from noise corrupted calibration vectors is developed. The key idea is to use a local parametric model of the sensor responses. The potential improvement using the suggested scheme rather than an ideal array model is demonstrated on real data collected from a full-scale hydro-acoustic array.
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| 6. |
- Goobar, E., et al.
(författare)
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Broadband measurements of frequency noise spectrum in two section DBR laser
- 1991
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 27, s. 289-291
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Tidskriftsartikel (refereegranskat)abstract
- The dependence of the frequency noise on the output power, the tuning current and the current modulation has been measured in a two electrode DBR laser from 30 MHz to 8 GHz. The frequency noise spectrum was fairly flat and decreased with increased output power at a rate faster than 1/P. At certain biasing levels, the noise increased and the relaxation peak was shifted towards lower frequencies when current was injected into the passive waveguide. Furthermore, the frequency noise was not affected by the current modulation.
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| 7. |
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| 8. |
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| 9. |
- Karlsson, Anders, et al.
(författare)
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Modulation and Noise Properties of Multi-element Semiconductor Lasers
- 1991
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In this report a previously presented theory for the modulation and noise properties of multi-element lasers is revised. Explicit formulas for modulation response, amplitude and frequency noise are found. The theory is illustrated by numerical examples.
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| 10. |
- Karlsson, A., et al.
(författare)
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On the modulation bandwidth of semiconductor microcavity lasers
- 1994
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Ingår i: IEEE Photonics Technology Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1041-1135 .- 1941-0174. ; 6, s. 1312-1314
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Tidskriftsartikel (refereegranskat)abstract
- The small signal injection current modulation bandwidth of vertical cavity microlasers in the conventional macroscopic regime and in the microscopic regime of "controlled spontaneous emission" is investigated. A microlaser, under constraint of nonlinear gain or current density limitations, is found to have the same intrinsic modulation bandwidth as conventional edge-emitting lasers with the same cavity losses and photon density.<>
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