Jacques Beneat

Performance of TOA estimation techniques in indoor multipath channels

The problem of TOA (time of arrival) estimation in multipath channels is discussed. Brief introductions of TOA estimation techniques that can be used to improve the performance in multipath channels are presented. Some simulation results based on channel measurement data in the indoor environment is presented to demonstrate and compare the performance of different TOA estimation techniques.

Advanced Design Techniques and Realizations of Microwave and RF Filters: Jarry/Design Techniques

Foreword. Preface. Part I: Microwave Filter Fundamentals. 1. Scattering Parameters and ABCD Matrices. 2. Approximations and Synthesis. 3. Waveguides and Transmission Lines. 4. Categorization of Microwave Filters. Part II: Minimum-Phase Filters. 5. Capacitive-Gap Filters for Millimeter Waves. 6. Evanescent-Mode Waveguide Filters with Dielectric Inserts. 7. Interdigital Filters. 8. Combline Filters Implemented In SSS. Part III: Non-Minimum-Phase Symmetrical Response Filters. 9. Generalized Interdigital Filters with Conditions on Amplitude and Phase. 10. Temperature-Stable Narrowband Monomode TE 011 Linear-Phase Filters. Part IV: Non-Minimum-Phase Asymmetrical Response Filters. 11. Asymmetrical Capacitive-Gap Coupled Line Filters. 12. Asymmetrical Dual-Mode TE 102 / TE 301 Thick Iris Rectangular In-Line Waveguide Filters with Transmission Zeros. 13. Asymmetrical Cylindrical Dual-Mode Waveguide Filters with Transmission Zeros. 14. Asymmetrical Multimode Rectangular Building Block Filters Using Genetic Optimization. Appendix 1: Lossless Systems. Appendix 2: Redundant Elements. Appendix 3: Modal Analysis of Waveguide Step Discontinuities. Appendix 4: Trisections with Unity Inverters on the Inside or on the Outside. Appendix 5: Reference Fields and Scattering Matrices for Multimodal Rectangular Waveguide Filters. Index.

Design of analog and digital data transmission filters

This work presents a design technique for continuous-time and discrete-time data transmission filters. These are pulse shaping networks allowing transmission with minimum intersymbol interference in the time domain, while providing high amplitude selectivity and a close approximation to a constant group delay over the band of interest in the frequency domain. The technique gives the denominator of the filter transfer function in analytic closed form, while its numerator is determined by solving a set of linear algebraic equations. This results in a very powerful, yet simple and straightforward design method, in contrast to existing techniques which usually require the solution of nonlinear equations. Furthermore, all the frequency- and time-domain requirements appear simultaneously in the design without any need for subsequent corrections or equalization. >

Measurement of TOA using frequency domain characteristics for indoor geolocation

Frequency domain techniques have been widely used for indoor radio propagation measurements and modeling for telecommunication applications. This paper addresses measurement of the time of arrival (TOA) of the first path for geolocation application using results of frequency domain channel measurements. First, we analyze the effect upon TOA measurement accuracy due to: sampling period of the radio channel in the frequency domain, sampling period in the time domain used for detection of the TOA and the windowing filter used before transformation to time domain. Then we provide some results of measurement in line of sight (LOS) and obstructed LOS (OLOS) indoor environments to compare the characteristics of the measured TOA in these two important scenarios for indoor geolocation applications.

Radio propagation modelling for indoor geolocation applications

A mathematical framework is introduced for statistical modelling of the wideband characteristics of the frequency selective multipath indoor radio channel for geolocation applications. The multipath characteristics of the channel are divided into three classes according to the availability and strength of the direct line-of-sight (DLOS) path with respect to the other paths. The distributions of the occurance of these classes as a function of distance are presented. The effects of the presence of an external wall between the transmitter and receiver are investigated.

Modeling of the wideband indoor radio channel for geolocation applications in residential areas

The wideband indoor radio channel has been characterized at a variety of center frequencies and building architectures for the purpose of evaluating the performance of communications systems. Emerging position location applications, both civilian and military, require information relevant to evaluate the performance of geolocation receivers that is significantly different from the information used for communications applications. In this paper, the differences in radio channel modeling for communications and geolocation applications are elaborated. Characterization of the radio channel for geolocation purposes is examined. The results of modeling for geolocation undertaken at four different radio frequencies in a residential area based on enhancements to the JTC model using radio channel measurements are presented.

Radio channel characterization for geolocation at 1 GHz, 500 MHz, 90 MHz and 60 MHz in SUO/SAS

In this paper, the results of measurements to characterize the radio channel for geolocation applications are presented. Measurements were made at 1 GHz, 500 MHz, 90 MHz and 60 MHz, in three different environments-commercial, office and residential areas-representative of SUO/SAS (small unit operation/situation awareness systems) scenarios. The characterization of the radio channel is provided through the cumulative distribution function (CDF) of the relative received power and the errors in estimated distances based on the first and strongest paths extracted from the channel impulse responses (CIR). These results are used to evaluate the corresponding performance of a RAKE type receiver that can extract the first path and a traditional type receiver that locks onto the strongest signal.

Miniaturized RF/microwave filters using fractals

The analysis and design of miniaturized fractal filters is presented in this paper. It is shown that fractal resonators can be significantly smaller than conventional planar resonators for the same resonant frequency requirements. It is seen that when increasing the number of fractal iterations, the size of the resonators decreases and the quality factor increases. The filter design method is based on the synthesis of an inline prototype with symmetrical or asymmetrical pseudo-elliptic characteristics and coupling factor simulations using a commercial electromagnetic simulator. The fractal filters were designed using suspended substrate technology and fabricated in house and with the services of a regular PCB company.

Fractal microwave filters

In order to meet the ever increasing demand for miniaturization of RF and microwave filters, the suitability of fractal resonators has been examined and a complete design method of miniaturized fractal filters has been developed.

Miniaturized Microwave Fractal Filters (M2F2)

The analysis and design of miniaturized fractal filters is presented in this article. It is shown that fractal resonators can be significantly smaller than conventional planar resonators for the same resonant frequency requirements. It is observed that when increasing the number of fractal iterations (typically 3), the size of the resonators decreases and the quality factor increases. The filter design method is based on the synthesis of an inline prototype with symmetrical or asymmetrical pseudo-elliptic characteristics and coupling factor simulations using a commercial electromagnetic simulator. The fractal filters were designed using suspended substrate technology and fabricated in-house and with the services of a regular printed circuit board company. Keywords: microwave filters; fractal filters; meandered line filters; Hilbert filters; Minkowski filters