# April 2008, Volume 17, Number 1

**N. Yannopoulou, P. Zimourtopoulos**
[references] [full-text]
[Download Citations]

S-Parameter Uncertainties in Network Analyzer Measurements with Application to Antenna Patterns

An analytical method was developed to estimate uncertainties in full two-port Vector Network Analyzer measurements, using total differentials of S-parameters. System error uncertainties were also estimated from total differentials involving two triples of standards, in the Direct Through connection case. Standard load uncertainties and measurement inaccuracies were represented by independent differentials. Complex uncertainty in any quantity, differentiably dependent on S-parameters, is estimated by the corresponding Differential Error Region. Real uncertainties, rectangular and polar, are estimated by the orthogonal parallelogram and annular sector circumscribed about the Differential Error Region, respectively. From the user\'s point of view, manufactures\' data may be used to set the independent differentials and apply the method. Demonstration results include: (1) System error differentials for Short, matching Load and Open pairs of opposite sex standards; (2) System error uncertainties for VNA extended by two lengthy transmission lines of opposite sex end-connectors; (3) High uncertainties in Z-parameters against frequency of an appropriately designed, DC resistive, T-Network; (4) Moderate uncertainties in amplitude and phase patterns of a designed UHF radial discone antenna (azimuthally rotated by a built positioner, under developed software control of a built hardware controller) polarization coupled with a constructed gain standard antenna (stationary) into an anechoic chamber.

- BALLO, D. Network Analyzer Basics. Hewlett-Packard, 1998, p.58.
- FITZPATRICK, J. Error models for systems measurement. Microwave Journal, May 1978, vol. 21, p. 63-66.
- STUMPER, U. Influence of TMSO calibration standards uncertainties on VNA S-parameters measurements. IEEE Transactions on Instrumentation and Measurements, April 2003, vol. 52, no. 2, p. 311 - 315.
- YANNOPOULOU, N., ZIMOURTOPOULOS, P. Total differential errors in one-port network analyzer measurements with application to antenna impedance. Radioengineering, June 2007, vol. 16, no. 2, p. 1-8.
- BEATTY, R. W., KERNS, D. M. Relationships between different kinds of network parameters, not assuming reciprocity or equality of the waveguide or transmission line characteristic impedances. Proceedings of the IEEE, Jan. 1964, vol. 52, issue 1, p. 84.
- BEATTY, R. W., KERNS, D. M. Correction to "Relationships ..." Proceedings of the IEEE, Apr. 1964, vol. 52, issue 4, p. 426.
- YANG, R. F. H. A proposed gain standard for VHF antennas. IEEE Transactions on Antennas and Propagation, November 1966, vol. 14, no. 6, p. 792.
- LYSOUDIS, G. Study and construction of a gain standard. Diploma Thesis #2, Antennas Research Group, DUTh, 1987 (in Greek).
- IEEE Standard Test Procedures for Antennas. IEEE Std 149-1979.
- BOWMAN, R. R. Field strength above 1 GHz: Measurement procedures for standard antennas. Proceedings of the IEEE, June 1967, vol. 55, no. 6, p. 981-990.
- High Performance RF Network Analyzer. Hewlett-Packard, Technical Data 1, Jan 1979, p.15.

Keywords: Microwave Measurements, Network Analyzer, Uncertainty, S-parameters, Z-parameters, Antenna Patterns

**Z. Elhadj**
[references] [full-text]
[Download Citations]

Analysis of a New Three-Dimensional Quadratic Chaotic System

This paper has reported the finding of a new simple three dimensional quadratic chaotic system with three nonlinearities obtained by adding a cross-product nonlinear term to the first equation of the Lu system. Basic properties of the system have been analyzed by means of Lyapunov exponent spectrum and bifurcation diagram of an associated Poincare map. This analysis shows that the system has complex dynamics with some interesting characteristics in which there are several periodic regions, but each of them has quite different periodic orbits. Shilnikov’s criterion is included and discussed.

- LORENZ, E. N. Deterministic nonperiodic flow. J. Atoms. Sc., 1963, vol. 20, p. 130 - 141.
- ROSSLOR, O. E. An equation for continuous chaos. Phys. Lett. A , 1976, vol. 57, p. 397 - 398.
- CHEN, G., UETA, T. Yet another chaotic attractor. Int. J. Bifur. Chaos, 1999, vol. 9, p. 1465 - 1466.
- LU, J. H., CHEN, G. A new chaotic attractor coined. Int. J. Bifurcat. Chaos, 2002, vol. 12, p. 659 - 661.
- LU, J. H., CHEN, G., CHENG, D., CELIKOVSKY, S. Bridge the gap between the Lorenz system and the Chen system. Int. J. Bifur. Chaos, 2002, vol. 12, no. 12, p. 2917 - 2926.
- QI, G., CHEN, G., DU, S. Analysis of a new chaotic system. Physica A, 2005, vol. 352, p. 295 - 308.
- CHEN, G. Controlling Chaos and Bifurcations in Engineering System. CRC Press, Boca Raton, FL, 1999.
- ELHADJ, Z., EDDINE, H. N. A generalized model of some Lorenz-type and quasi-attractors type strange attractors in three-dimensional dynamical systems. International Journal of Pure & Applied Mathematical Sciences, 2005, vol. 2, no. 1, p. 67 - 76.
- CHEN, G., DONG, X. From Chaos to Order: Methodologies, Perspectives and Applications. (World Scientific, Singapore), 1998.
- YU, W. W., CAO, J., WONG, K. W., LU, J. New communication schemes based on adaptive synchronization. Chaos, 2007, vol. 17, no. 3, p. 033 - 114.
- SPROTT, J. C. Chaos and Time-Series Analysis. Oxford University Press, Oxford, 2003.
- PARKER, T.S., CHUA, L.O. Practical Numerical Algorithms for Chaotic Systems. Springer Verlag, New York, 1989.
- YU, S. M., LU, J., CHEN, G. Theoretical design and circuit implementation of multi-directional multi-torus chaotic attractors. IEEE Trans. on Circuits and Systems I, 2007, vol. 54, no.9, p. 2087 - 2098.
- AULBACH, B., FLOCKERZI, D. The past in short hypercycles. J. Math. Biol, 1989, vol. 27, p. 223 - 231.
- BALMFORTH, N. J. Solitary waves and homoclinic orbits. Annual review of fluid mechanics, 1995, vol. 27, p. 335 - 373, Annual Reviews, Palo Alto, CA.
- SHILNIKOV, L. P. A case of the existence of a countable number of periodic motions. Sov. Math. Doklady, 1965, vol. 6, p. 163 - 166 (translated by S. Puckette).
- SHILNIKOV, L. P. A contribution of the problem of the structure of an extended neighborhood of rough equilibrium state of saddle-focus type. Math. U.S.S.R.Sbornik, 1970, vol. 10, p. 91-102 (translated by F. A. Cezus).

Keywords: New chaotic attractors, three quadratic nonlinearities, modified Lu system; Lyapunov exponent spectrum, bifurcation diagram, Poincare map

**R. Zajicek, L. Oppl, J. Vrba**
[references] [full-text]
[Download Citations]

Broadband Measurement of Complex Permittivity Using Reflection Method and Coaxial Probes

This paper describes and evaluates a method for determining complex permittivity, and presents results of permittivity measurement of some substances. Complex permittivity of a phantom of biological muscle tissue, of some industrial chemicals and dielectrics is found. A non-destructive and non-invasive method based on reflection coefficient measurement of an open-ended coaxial line attaching the material under test is used. Two coaxial probes are under investigation. Vector measurement of the reflection coefficient on the interface between probes and measured samples is performed with the aid of network analyzer in the frequency range from 300 kHz to 3 GHz. Numerical modeling (FDTD) is compared with measurement. The results indicate that using the coaxial probe with dimensions of N connector the method is suitable in the frequency range approximately from 30 MHz to 1 GHz and using the probe with dimensions of SMA connector in range approximately from 30 MHz to 3 GHz.

- VRBA, J. Medical Applications of Microwave Technique. Press CTU in Prague, 2003. (in Czech)
- GABRIEL, S., LAU, R. W., GABRIEL, C. The dielectric properties of biological tissues: III. Parametric models for the dielectric spectrum of tissues. Phys. Med. Biol., 1996, 41, p. 2271-2293.
- STUCHLY, M. A., et al. Measurement of radio frequency permittivity of biological tissues with open-ended coaxial line: Part I IEEE Trans. Microwave Theory Tech., 1982, vol. MTT30, pp. 82-92.
- OPPL, L. Measurement of Dielectric Properties. Dissertation Thesis, CTU in Prague, Dept. of EM field, 2001. (in Czech)
- NOVOTNY, K. Theory of Electromagnetic Field. Press CTU in Prague, 1997. (in Czech)
- HUDLICKA, M., HAZDRA, P. Finite Integration Technique. In: Modeling of Fields. IEEE Czechoslovak Section, 2006, p. 58-77.
- http://niremf.ifac.cnr.it/tissprop/ Dielectric properties of body tissues developed by C.Gabriel and colleagues.

Keywords: Complex permittivity measurement, vector reflection coefficient measurement, coaxial probes.

**R. Galuscak, M. Watanabe, P. Hazdra, S. Takeda, K. Seki, M. Prochazka, Y. Uchiyama**
[references] [full-text]
[Download Citations]

Design of Primary Feeds for 32m KDDI Antenna System IBA-4 in Cassegrain Configuration

Physically large dimensional dish antennas in Cassegrain configuration have played an important role in satellite communications during the past several decades. Recently, however, emerging new technologies have begun to displace these elegant antennas in professional telecommunication service due to their lower operating costs. A beneficial aspect of this transitional situation is that it has created opportunities for amateur radio enthusiasts to use these soon-to-be-retired dish antenna systems for limited experimental testing. Adaptation of these professionally designed antennas to bands allocated for amateur radio service presents excellent educational opportunities in using antenna engineering skills and the use of modern electromagnetic simulation software provides a novel perspective for these antenna design and transformation tasks.

- ICARA, Induced Current Analysis of Reflector Antennas-software, www.com.uvigo.es/ant/icara_english.htm
- MILLIGAN, T. A. Modern Antenna Design. Wiley-IEEE Press, 2nd edition, July 11, 2005.
- FEKO EM systems-Software & SS.A. (Pty) Ltd, www.feko.info
- Computer Simulation Technology, www.cst.de
- PROCHAZKA, M. Vypocet antenni soustavy Cassegrain s tvarovou korekci zrcadel. Slaboproudy obzor, 1983, no. 12. (In Czech.)
- KILDAL, P.S. The effects of subreflector diffraction on the aperture efficiency of a conventional Cassegrain antenna-An analytical approach. IEEE Trans AP, 1983, vol. 31, no. pp 903 – 909.
- GALUSCAK, R., HAZDRA, P. Prime-focus circular waveguide feed with septum polarization transformer. DUBUS, 1/2007.
- CARTER, D. Phase centers of microwave antennas. IRE Transactions on Antennas and Propagation, 1956, pp. 597 – 600.
- PROCHAZKA, M. Kelvin Sum software. Privately developed software program, 1999.
- BUI-HAI: Antennes Micro-Ondes, 08/01/1999 MASSON.
- Project BIG DISH, http:// 8N1EME.jp
- WADE, P. Multiple Reflector Dish Antennas. www.w1ghz.org/antbook/conf/conf.htm

Keywords: Cassegrain antenna, EME communication, Primary feed, Circular polarization, Dish antenna, Project Big Dish, KDDI antenna

**M. Pokorny, J. Horak, Z. Raida**
[references] [full-text]
[Download Citations]

Planar Tri-Band Antenna Design

The paper briefly uncovers techniques used for a design of compact planar antennas in order to achieve the wideband and the multi-band capability. The main topic is aimed to the multi-objective optimization using genetic algorithms.

A quarter-wavelength planar inverted-F antenna (PIFA) using a slot and shorted parasitic patches is chosen to cover GSM900, GSM1800 and ISM2400 bands.

A global multi-objective optimization uses a binary genetic algorithm with a composite objective function to tune this antenna. The impedance match and the direction of maximum gain are desired parameters to improve.

- CIAIS, P., STARAJ, R., KOSSIAVAS, G., LUXEY, C. Design of an internal quad-band antenna for mobile phones. IEEE Microwave and Wireless Components Letters, April 2004, Vol. 14, no. 4, p. 148 - 150.
- KHOO, C. W. Multiband Antenna for Handheld Transceivers. Bachelor thesis. Ipswich: The University of Queensland, Online: http://innovexpo.itee.uq.edu.au/2002/projects/s4000751/thesis.pdf.
- RAIDA, Z. Optimization in Electrical Engineering. Online: http://www.urel.feec.vutbr.cz/~raida/optimalizace/index.htm.en
- CERNOHORSKY, D., RAIDA, Z., SKVOR, Z., NOVACEK, Z. Analyza a optimalizace mikrovlnnych struktur (Analysis and Optimization of Microwave Structures). Brno: VUTIUM Publishing, 1999. (In Czech.)
- Arlon Product Datasheets. Rancho Cucamonga: Arlon-MED., 2006.
- HERAS, E., RAIDA, Z., LAMADRID, R. Quad-band U-slot antenna for mobile applications. Radioengineering, 2006, vol. 15, no. 2, p. 22 to 29.
- IE3D Reference Manual. Fremont: Zeland Software Inc., 2006.
- DEB, K. Multi-Objective Optimization using Evolutionary Algorithms. New York: John Wiley & Sons, 2001.

Keywords: Multi-objective optimization, multi-band antenna, planar antenna, genetic algorithm, GSM, ISM, Matlab, IE3D

**J. Jilkova, Z. Raida**
[references] [full-text]
[Download Citations]

Ultra-Wideband Coplanar-Fed Monopoles: A Comparative Study

The paper provides an experimental comparison of four types of ultra-wideband coplanar-fed planar monopole antennas. Parameters of the open stub completed by an L-shaped monopole and the cross monopole were adopted from the literature. The forked monopole and the coplanar monopole were fabricated and measured.

Monopoles were compared from the viewpoint of the impedance bandwidth, gain, directivity patterns and dimensions.

- KIM, J. I., JEE, Y. Design of ultra-wideband coplanar waveguide-fed LI-shape planar monopole antennas. Antennas and Wireless Propagation Letters. 2007, vol. 6, p. 383–387.
- DEEPU, V. D. V., RAJ, R. K., JOSEPH, M., MOHANAN, P. Compact asymmetric coplanar strip fed monopole antenna for multiband applications. IEEE Transactions on Antennas and Propagation. 2007, vol. 55, no. 8, p. 2351–2357.
- LIN, Y. F., LIN, C. H., CHEN, H., M., HALL, P. S. A miniature dielectric loaded monopole antenna for 2.4/5 GHz WLAN applications. Microwave and Wireless Components Letters. 2006, vol. 16, no. 11, p. 591–593.
- ZACHOU, V., CHRISTODOULOU, C. G., CHRYSSOMALLIS, M. T., ANAGNOSTOU, D., BARBIN, S. Planar monopole antenna with attached sleeves. IEEE Antennas and Wireless Propagation Letters. 2006, vol. 5, p. 286–289.
- KIM, J., YOON, T., JAEMOUNG, K., CHOI, J. Design of an ultra wide-band printed monopole antenna using FDTD and genetic algorithm. Microwave and Wireless Components Letters. 2005, vol. 15, no. 6, p. 395–397.
- LIU, W. C. Design of a multiband CPW-fed monopole antenna using a particle swarm optimization approach. IEEE Transactions on Antennas and Propagation. 2005, vol. 53, no. 10, p. 3273–3279.
- CHEN, H. D., CHEN, H. T. A CPW-fed dual-frequency monopole antenna. IEEE Transactions on Antennas and Propagation. 2004, vol. 52, no. 4, p. 978–982.
- CST Microwave Studio User’s Guide. Darmstadt: CST Gmbh, 2007.
- ROBINSON, J., RAHMAT-SAMII, Y. Particle swarm optimization in electromagnetics. IEEE Transactions on Antennas and Propagation. 2004, vol. 52, no. 2, p. 397–407.

Keywords: Ultra-wideband monopole antennas, coplanar feeding, planar antennas, numerical modeling

**J. Holis, P. Pechac**
[references] [full-text]
[Download Citations]

Provision of 3G Mobile Services in Sparsely Populated Areas Using High Altitude Platforms

This paper deals with the application of High Altitude Platforms for the provision of third generation mobile services in sparsely-populated areas or in developing countries. It focuses on the behavior of large cells provided via a multiple HAP deployment and shows the possibilities of using small cells located inside these large cells to serve hot-spot areas. The impact of the different types of HAP antenna masks and their adjustment on cell capacity and the quality of coverage is presented. The main parameter of the antenna radiation pattern under investigation is the power roll-off at the cell edge. Optimal values of this parameter are presented for different scenarios. Simulations of system level parameters were based on an iteration loops approach.

- HOLMA, H., TOSKALA, A. WCDMA for UMTS – HSPA Evolution and LTE. 4th ed., John Wiley & Sons, 2007.
- LAIHO, J., WACKER, A. NOVOSAD, T., Radio Network Planning and Optimization for UMTS. 2nd ed., John Wiley & Sons, 2005.
- HOLMA, H., TOSKALA, A. HSDPA/HSUPA for UMTS: High Speed Radio Access for Mobile Communications. John Wiley & Sons, 2006.
- TOZER, T. C., GRACE, D. High-altitude platforms for wireless communications. IEE Electron. Commun. Eng. J., June 2001, vol. 13, no. 3, pp.127-137.
- Preferred characteristics of systems in the fixed service using high- altitude platform stations operating in the bands 47.2–47.5 GHz and 47.9–48.2 GHz. Int. Telecommunications Union, Recommendation ITU-R F.1500, 2000.
- Minimum performance characteristics and operational conditions for high altitude platform stations providing IMT-2000 in the Bands 1885–1980 MHz, 2010–2025 MHz and 2110–2170 MHz in the Regions 1 and 3 and 1885–1980 MHz and 2110–2160 MHz in Region 2. Int. Telecommunications Union, Recommendation ITU- R M.1456, 2000.
- HOLIS, J., PECHAC, P., Simulation of UMTS networks provided via HAP stations using elliptical and circular beam antennas in urban and suburban areas. In Proceedings of the 9th International Symposium Wireless Personal Multimedia Communications – WPMC’06. San Diego (USA), September 2006, p. 348-351.
- SAUNDERS, S. R., ARGO-ZAVALA, A. Antennas and Propagation for Wireless Communication Systems. 2nd ed., John Wiley & Sons, 2007.
- PARKS, M. A. N., EVANS, B. G., BUTT, G. High elevation angle propagation results applied to a statistical model and an enhanced empirical model. IEE Electronics Letters, September 1993, vol.29, no.19, p. 1723-1725.
- AXIOTIS, D. I., THEOLOGOU, M. E. An empirical model for predicting building penetration loss at 2 GHz for high elevation angles. IEEE Antennas and Wireless Propagation Letters, 2003, vol. 2, pp. 234-237.
- THORTON, J., GRACE, D., CAPSTICK, M. H., TOZER, T. C. Optimizing an array of antennas for cellular coverage from a high altitude platform. IEEE Trans. Commun., May 2003, vol. 2, pp. 484-to 492.
- BALANIS, C. A. Antenna Theory, Analysis and Design. 2nd ed., John Wiley & Sons, 1997.
- HOLIS, J., PECHAC, P. Simulation of UMTS capacity and quality of coverage in urban macro- and microcellular environment. Radioengineering, December 2005, vol. 14, no. 4, pp. 21-26.
- Guidelines for evaluation of radio transmission technologies for IMT-2000. Int. Telecommunications Union, Recommendation ITU-R M.1225, 1997.

Keywords: High Altitude Platforms (HAPs), UMTS, Antennas, 3G Mobile services

**K. Ulovec**
[references] [full-text]
[Download Citations]

Recognition of OFDM Modulation Method

This contribution deals with asynchronous noncoherent recognition of modulation types. The main aim is to recognize OFDM modulation method from some other single-carrier analog and digital modulation types in the presence of AWGN noise. The described solution of recognizer uses key features of the received signal. The signal amplitude is observed at the output of the quadrature intermediate-frequency stage. The properties of the recognizer are verified by simulations using Matlab.

- DUBUC, C., BOUDREAU, D., PATENAUDE, F., INKOL, R. An automatic modulation recognition algorithm for spectrum monitoring applications. In International Communications Conference, Vancouver, 1999.
- OCTAVIA, A. D., WEI, S. On the classification of linearly modulated signals in fading channels. In Conference on Information Science and Systems, Princeton University, 2004.
- AZZOUZ, E. E., NANDI, A, K. Automatic identification of digital modulation types. Signal Processing, 1995, vol.47, no.1, pp. 55-69.
- SWAMI, A., SADLER, B. Hierarchical digital modulation classification using cumulants. IEEE Transactions on Communication, 2000, vol. 48, no. 3, p. 416–429.
- NANDI, A. K., AZZOUZ, E. E. Automatic analog modulation recognition. Signal Processing, 1995, vol. 46, p.211-222.
- AKMOUCHE, W. Detection of Multicarrier Modulations Using 4th-Order Cumulants. IEEE, 1999.

Keywords: Noncoherent asynchronous recognition, OFDM modulation method, AWGN noise, quadrature intermediate-frequency signal, signal key feature, correct recognition, false alarm, simulation

**M. Khelladi, O. Seddiki, F. T. Bendimerad**
[references] [full-text]
[Download Citations]

Time-Frequency Decomposition of an Ultrashort Pulse: Wavelet Decomposition

An efficient numerical algorithm is presented for the numerical modeling of the propagation of ultrashort pulses with arbitrary temporal and frequency characteristics through linear homogeneous dielectrics. The consequences of proper sampling of the spectral phase in pulse propagation and its influence on the efficiency of computation are discussed in detail. The numerical simulation presented here is capable of analyzing the pulse in the temporal-frequency domain. As an example, pulse propagation effects such as temporal and spectral shifts, pulse broadening effects, asymmetry and chirping in dispersive media are demonstrated for wavelet decomposition.

- CHRITOV, I. P. Propagation of femtosecond light pulses. Opt. Commun., 1985, vol. 53, no. 6, pp. 364- 366.
- ZIOLKOWSKI, R. W., JUDKINS, J. B. Propagation characteristics of ultrawide bandwidth pulsed Gaussian beams. J. Opt. Soc. Am. A, 1992, vol. 11, pp. 2021-2030.
- SHEPPARD, C. J. R., GAN , X. Free-space propagation of femto-second light pulses. Opt. Commun., 1997, vol. 133, pp. 1-6.
- AGRAWAL, G. P. Spectrum-induced changes in diffraction of pulsed beams. Opt. Commun., 1998, vol. 157, pp. 52-56.
- KAPLAN, A. E. Diffraction-induced transformation of near cycle and subcycle pulses. J. Opt. Soc. Am. B, 1998, vol. 15, pp. 951-956.
- AGRAWAL, G. P. Far-field diffraction of pulsed optical beams in dispersive media. Opt. Commun., 1999, vol. 167, pp. 15-22.
- PORRAS, M.A. Propagation of single-cycle pulse light beams in dispersive media. Phys. Rev. A, 1999, vol. 60, no. 6, pp. 5069-5073.
- ICHIKAWA, H. Analysis of femtosecond-order optical pulses diffracted by periodic structure. J. Opt. Soc. Am. A, 1999, vol. 16, pp. 299-304.
- PIESTUN, R., MILLER, D. B. Spatiotemporal control of ultrashort optical pulses by refractive-diffractive-dispersive structured optical elements. Opt. Let., 2001, vol. 26, pp. 1373-1375.
- KEMPE, M., STAMM, U., WILHELMI, B., RUDOLPH, W. Spatial and temporal transformation of femtosecond laser pulses by lenses systems. J. Opt. Soc., 1999, vol. 38, pp. 1058-1064.
- MATTEI, G. O., GILI, M. A. Spherical aberration in spatial and temporal transformation of femtosecond laser pulses by lenses and lens systems. J. Opt. Soc. Am. B, 1992, vol. 9, pp. 1158-1165.
- FUCHSS, U., ZEITNER, U. D., TUNNERMENN, A. Ultrashort pulse propagation in complex optical systems. Opt. Express, 2005, vol. 13, pp. 3852-3861.
- LEONID, S., FERRARI, A., BERTOLOTTI, M. Diffraction of a time Gaussian-shaped pulsed plane wave from a slit. Pure. Appl. Opt., 1996, vol. 5, pp. 349-353.
- HWANG, H .E., YANG, G. H. Far-field diffraction characteristics of a time variant Gaussian pulsed beam propagation from a circular aperture. Opt. Eng., 2002, vol. 41, pp. 2719-2727.
- LIU, Z., LU, B. Spectral shifts and spectral switches in diffraction of ultrashort pulsed beams passing through a circular aperture. Optik, 2004, vol. 115, pp. 447-454.
- HWANG, H.E., YANG, G. H. Near-field diffraction characteristics of a time dependent Gausian pulsed beam propagating from a circular aperture. Opt. Eng., 2003, vol. 42, pp. 2719-2727.
- WYROWSKI, F., TURUNEN, J. Wave-optical engineering. In International Trends in Applied Optics. A. H.Guenther, ed. SPIE Press, 2002.
- RULLIERE, C. Femtosecond Laser Pulses: Principles and Experiments. Springer Ed., 1998.
- MARCUSE, D. Light Transmission Optics. New York: Van Nostrand Reinhold, 1982. Chaps. 8 and 12.
- COHEN, L.G. J. Light Wave Technol. LT-3, 958 (1985).
- ADAMS, M. J. An Introduction to Optical Waveguides Theory. London: Chapman and Hall, 1983.
- KHELLADI, M. Ultra-short Laser Pulses Characterizations: Wavelet Decomposition. Thesis, University of Tlemcen. Algeria, 2005.
- MEYER, Y., JAFFORT, S., RIOUL, O. Wavelet Analysis. Edition Francaise de scientifique American, 1987.

Keywords: Refraction index, femtosecond pulse, chromatic dispersion, chirp, Fourier analysis, wavelet decomposition

**S. P. Maity, S. Maity**
[references] [full-text]
[Download Citations]

Wavelet Based Hilbert Transform with Digital Design and Application to QCM-SS Watermarking

In recent time, wavelet transforms are used extensively for efficient storage, transmission and representation of multimedia signals. Hilbert transform pairs of wavelets is the basic unit of many wavelet theories such as complex filter banks, complex wavelet and phaselet etc. Moreover, Hilbert transform finds various applications in communications and signal processing such as generation of single sideband (SSB) modulation, quadrature carrier multiplexing (QCM) and bandpass representation of a signal. Thus wavelet based discrete Hilbert transform design draws much attention of researchers for couple of years. This paper proposes an (i) algorithm for generation of low computation cost Hilbert transform pairs of symmetric filter coefficients using biorthogonal wavelets, (ii) approximation to its rational coefficients form for its efficient hardware realization and without much loss in signal representation, and finally (iii) development of QCM-SS (spread spectrum) image watermarking scheme for doubling the payload capacity. Simulation results show novelty of the proposed Hilbert transform design and its application to watermarking compared to existing algorithms.

- PROAKIS, J. G., MANOLAKIS, D. G., SARMA, D. Digital Signal Processing. New Delhi: Pearson Education, 2006.
- HAYKIN, S. Communication Systems. 3rd ed. Singapore: John Wiley & Sons, 1995.
- BURRUS, C. S., GOPINATH, R. A., GUO, H. Introduction to Wavelets and Wavelet Transforms, A Primer. New Jersey: Prentice Hall, 1997.
- PENNEC, E. L., MALLAT, S. Sparse geometric image representations with bandelets. IEEE Transactions on Image Processing, 2005, vol. 14, no. 4, p. 423-438.
- MEERWALD, P., UHL, A. A survey of wavelet domain watermarking. In Proceedings of SPIE, Electronic Imaging, Security and Watermarking of Multimedia Contents III, vol. 4314, 2001.
- COX, I. J., KILIAN, J., LEIGHTON, F. T., SHAMOON, T. Secure spread spectrum for multimedia. IEEE Transaction on Image Processing, 1997, vol. 6, p. 1673–1687.
- LANGELAAR, G. C., SETYAWAN, I., LAJENDIJK, R. L. Watermarking in digital images and video data. IEEE Signal Processing Magazine, 2000, vol. 17, p. 20–46.
- GROBOIS, R., EBRAHIMI, T. Watermarking in JPEG 2000 domain. In Proc. of the IEEE Workshop on Multimedia Signal Processing, 2001, p. 3–5.
- MAITY, S. P., KUNDU, M. K. A blind CDMA image watermarking scheme in wavelet domain. In Proceedings of IEEE International Conference on Image Processing, 2004, p. 2633–2636.
- ABRY, P., FLANDRIN, P. Multiresolution transient detection. In Proc. of IEEE-SP Int. Symp. Time-Frequency, Time-Scale Analysis, 1994, p. 225–228.
- ABRY, P. Ondelettes et Turbulences. Paris, France: Diderot, 1997.
- OZTURK, E., KUCUR, O., ATKIN, G. Waveform encoding of binary signals using a wavelet and its Hilbert transform. In Proc. of IEEE Int. Conf. on Acoust., Speech, Signal Process., June 5–9, 2000.
- SELESNICK, I. W. Hilbert transform pairs of wavelet bases. IEEE Signal Processing Letter, 2001, vol. 8, p. 170–173.
- FREEMAN, W. T., ADELSON, E. H. The design and use of steerable filters. IEEE Transaction on Pattern Analysis and Machine Intelligence, 1991, vol. 13, p. 891–906.
- SIMONCELLI, E. P., FREEMAN, W. T. The steerable pyramid: A flexible architecture for multi-scale derivative computation. In Proc. of IEEE International Conference on Image Processing, 1995.
- KINGSBURY, N. G. The dual-tree complex wavelet transform: A new technique for shift invariance and directional filters. In Proceedings of the Eighth IEEE DSP Workshop, 1998.
- KINGSBURY, N. G. A dual-tree complex wavelet transform with improved orthogonality and symmetry properties. In Proceedings of IEEE Int. Conference on Image Processing, 2000.
- MAITY, S. P., MAITY, S. Design of Hilbert transform using discrete wavelet. In Proceedings of Int. Conference on Computers and Devices for Communication (CODEC-2006), Kolkata (India), 2006.
- MAITY, S. P., KUNDU, M. K., MAITY, S. Capacity improvement in digital watermarking using QCM scheme. In Proc. of the 12th National Conf. on Communications, IIT Delhi, 2006, p. 511-515.
- CHENG, L., WANG, H. The solution of III- conditioned stoeplitz systems via two-grid and wavelet method. Comp. Math. Appl., 2003, vol. 46, no. 6.
- CHENG, L., XIANG, D. General construction of 9/7 wavelet filter and its application in image compression. Optical Engineering, 2003, vol. 42, no. 8.
- BAUDRY, S., DELAIGLE, J. F., SANKUR, B., MAITRE, H. Analysis of error correction strategies for typical communication channel in watermarking. Signal Processing, 2001, vol. 81, no. 6, p. 1239-1250.
- MAITY, S. P., KUNDU, M. K., DAS, T. S. Robust SS watermarking with improved capacity. Pattern Recognition Letters, 2007, vol. 28, p. 350-356.
- GONZALEZ, R. C., WOODS, R. E. Digital Image Processing. 2nd ed. Singapore: Pearson Education Inc., 2002.
- SCHONER, B., VILLASENOR, J., MOLLOY, S., JAIN, R. Techniques for FPGA implementation of video compression systems. In Proc. of ACM/SIGBA International Symposium on FPGA, 1995.
- WANG, Z., BOVIK, A. C., SHEIKH, H. R., SIMONCELLI, E. P. Image quality assessment: From error measurement to structural similarity. IEEE Trans. on Image Processing, 2004, vol. 13, p. 1–14.
- KUNDUR, D., HATZINAKOS, D. A robust digital image watermarking method using wavelet based fusion. In Proceedings of IEEE International Conf. on Image Processing, 1997, p. 544-547.

Keywords: Hilbert transform, wavelets, biorthogonal wavelets, hardware design, QCM-SS watermarking

**E. Chromy, I. Baronak**
[references] [full-text]
[Download Citations]

Common Virtual Path and Its Expedience for VBR Video Traffic

The paper deals with utilization of common Virtual Path (VP) for variable bit rate (VBR) video service. Video service is one of the main services for broadband networks. Research is oriented to statistical properties of common and separate VPs. Separate VP means that for each VBR traffic source one VP will be allocated. Common VP means that for multiple VBR sources one common VP is allocated. VBR video traffic source is modeled by discrete Markov chain.

- Video Traces for Network Performance Evaluation. Arizona State University, http://trace.eas.asu.edu/tracemain.html
- ROSE, O. Traffic Modeling of Variable Bit Rate MPEG Video and its Impacts on ATM Networks. Bayerische Julius-Maximilians-Unversitat Wurzburg, 1997.
- ALHERAISH, A. Autoregressive video conference models. International Journal of Network Management, September, 2004, vol. 14, p. 329-337.
- CSELENYI, I.., MOLNAR, S. VBR video source characterization and a practical hierarchical model. Telecommunication Systems, 2001.
- SARKAR, U., RAMAKRISHNAN, S., SARKAR, D. Modeling full-length video using Markov-modulated gamma-based framework. IEEE/ACM Transactions on Networking (TON), 2003, vol. 11, p. 638-649.
- LU, Y. Q., PETR, D., FROST, V. Survey of Source Modeling Technique for ATM Networks. Technical Report TISL-10230-1, University of Kansas, September 1993.
- ZHANG, X., SHIN, K. Markov-chain modeling for multicast signaling delay analysis. IEEE/ACM Transactions on Networking, August, 2004, vol. 12, p. 667-680.
- LUCANTONI, D., NEUTS, M., REIBMAN, A. Methods for performance evaluation of VBR video traffic models. IEEE/ACM Transactions on Networking, April, 1994, vol. 2 , no. 2, p. 176-180.
- BOLCH, G., GREINER, S., MEER, H., TRIVEDI, K. Queueing Networks and Markov Chain, Modeling and Performance Evaluation with Computer Science Applications. Second Edition, John Wiley & Sons, Inc., Hoboken, New Jersey, 2006, ISBN-10: 0-471-56525-3.
- KAVACKY, M. Connection admission control methods in ATM networks. In 7th International Conference Research in Telecommunication Technology RTT 2006. Brno (Czech Republic), September 11 - 13, 2006.

Keywords: NGN, ATM, Quality of Service, common Virtual Path, VBR video traffic, Markov model

**B. Tsankov, R. Pachamanov, D. Pachamanova**
[references] [full-text]
[Download Citations]

Resource Planning for Voice over Wireless Both-Way Transmission Media

The medium in IEEE 802.11- and IEEE 802.16-based networks for voice communications can be considered “both-way” - for transmission and reception. Therefore, the packet arrivals for voice dialogue services in such networks are not strictly independent. In this paper, we discuss the traffic capacity in the call (network) layer and suggest accounting for the impact of the correlated nature of two-way voice conversations on performance estimation. We present analytical results and numerical examples.

- SONG, J.-Y. et al. Performance comparison of 802.16d OFDMA, TD-CDMA, cdma2000 1xEV-DO and 802.11a WLAN on voice over IP service. In IEEE 61st Vehicular Technology Conf., VTC 2005, vol. 3, pp. 1965 – 1969.
- ZHAO, D., SHEN, X. Performance of packet voice transmission using IEEE 802.16 protocol. IEEE Wireless Communications, Feb. 2006, vol. 13, pp. 44-51.
- WANG, W., LIEW, S. C., LI, V. O. K. Solutions to performance problems in VoIP over a 802.11 wireless LAN. IEEE Trans. Vehicular Techn., Jan. 2005, vol. 54, pp. 366-384.
- GOODE, B. Voice over internet protocol (VoIP). Proc. of the IEEE, Sep. 2002, vol. 90, pp. 1495-1517.
- SZE, H. P., LIEW, S. C., LEE, J. Y. B., YIP, D. C. S. A multiplexing scheme for H.323 voice over IP applications. IEEE J. on Selected Areas in Comms., Sep. 2002, vol. 20, pp. 1360-1368.
- LEE, H., KWON, T., CHO, D.-H. An enhanced uplink scheduling algorithm based on voice activity for VoIP services in IEEE 802.16d/e system. IEEE Communications Letters, Aug. 2005, vol. 9, pp. 691–693.
- WANG, P., JIANG, H., ZHUANG, W. IEEE 802.11e enhancement for voice service. IEEE Wireless Communications, Feb. 2006, vol. 13, pp. 30-33.
- MALONE, D., CLIFFORD, P., LEITH, D. On buffer sizing for voice in 802.11 WLAN. IEEE Communications Letters, Oct. 2006, vol. 10, pp. 701–703.
- HEGDE, N., PROUTIERE, A., ROBERTS, J. Evaluating the voice capacity of 802.11 WLAN under distributed control. Proc. IEEE LANMAN 2005, 18-21 Sept. 2005, pages: 6 pp.
- DUFFY, K., MALONE, D., LEITH, D. J. Modeling the 802.11 distributed coordination function in non-saturated conditions. IEEE Communications Letters, Aug. 2005, vol. 9, pp. 715–717.
- SCHAAR, M. van der, SHANKAR, N. S. Cross-layer wireless multimedia transmission: challenges, principles, and new paradigms. IEEE Wireless Communications, Aug. 2007, vol. 14, pp. 50-58.
- CHENG, Y. et al. A cross-layer approach for WLAN voice capacity planning. IEEE J. on Selected Area in Communications, May 2007, vol. 25, no. 4, pp. 678-688.
- HUI, D. S. W., LAU, V. K. N., LAM, W. H. Cross-layer design for OFDMA wireless systems with heterogeneous delay requirements. IEEE Transactions on Wireless Communications, 2007, vol. 6, no. 8, pp. 2872-2880.
- PITTS, J. M., SCHORMANS, J. A. Introduction to IP and ATM Design and Performance. Chichester, England: John Wiley, 2000.
- MAKROPOULOU, A. P., TOBAGI, F. A., KARAM, M. J. Assessing the quality of voice communications over Internet backbone. IEEE/ACM Transactions on Networking, Oct. 2003, vol. 11, no. 5, pp. 747-760.

Keywords: IEEE 802.11, IEEE 802.16, voice call capacity, WLAN, WMAN