L. de Haro

Comparative study of LMS and RLS adaptive algorithms in the optimum combining of uplink W-CDMA

The performance of LMS and RLS adaptive algorithms for optimum combining applied to the reverse link of W-CDMA is studied in terms of SINR and computational load. Results are shown for different antenna array configurations in the base station site (number and separation between antenna elements, individual radiation patterns) and system scenarios (number and azimuthal distribution of users). Special emphasis is made on the antenna structure, and on the algorithm complexity, practical implementation and performance.

Shaped compact dual reflector antenna for Ku-band satellite pico-terminals

Pico-terminals for digital communications satellite systems need compact reflector antennas with a high aperture efficiency but with a controlled side lobe level. Shaped reflectors with an also shaped splash-plate meet both conditions satisfactorily. Such a solution was selected for the antenna of the remote user terminal of a CDMA satellite system (PRODAT project). This paper discusses its design and features.

A wideband OFDM MIMO measurement system for antenna evaluation

An OFDM-MIMO testbed based on a SDR platform with very flexible antenna positioning system has been designed and presented for WLAN applications. Antenna positioning allows the proper spatial characterization of radio channel links in real scenarios where future wireless networks will be deployed. Some measurements in real indoor scenarios proving reconfigurable antennas are been carried out leading to some interesting results that will be presented in the conference.

Experiences on tuned multiband fractal antennas

This paper presents a study of reconfigurable fractal antennas employing capacitance variations in the fractal structure. The input characteristics of this kind of antenna can be made frequency-agile using capacitive elements in a manner that partially modify an iteration or a group of iterations. By modifying that capacitance, a wideband via tuning could be achieved.

Development of a Cantor fractal array

Fractal antennas and fractal arrays are usually designed to have a multiband performance. However, in the case where the array elements are fractals, the design of a fractal array may have some problems. Moreover, array feeder bandwidth is usually limited, not allowing a real multiband performance. This abstract proposes a solution to get a real multiband bandwidth. Criteria for the design techniques are here described and results from theoretical analysis using MoM are presented.

A novel 3D hybrid FEM high-frequency technique for the analysis of scattering problems

A novel hybrid finite element method (FEM) and high frequency technique for the efficient analysis of scattering problems is presented. The hybrid method proposed makes use of an iterative FEM for open region problems that allows the easy hybridization with other numerical techniques. Results of the analysis of 2D scattering problems using physical optics (PO) as the high frequency technique are given showing some of the features of the method.

Antennas feasibility study for a LMDS communication system

Some antennas solutions are presented for new LMDS systems at 42 GHz. For the terminal antennas multiflare horns with dielectric lens and shaped Gregorian splash reflectors are presented. For the base stations omnidirectional single and dual shaped reflector solutions are described. Although the specifications are tentative, they are representative enough to the obtained results.

DOA measurements on indoor channel based on music and MDL processing

In indoor communications, the multipath propagation is fundamental. Generally, several replicas of the signal impinge in the receiving antenna. When there is line of sight, the received energy will be centered in a single wave. In the opposite case, the energy received in the array, is divided in several directions of the multipath, the signal simulates to have arrived from several sources of signal. In our case, using the results of a measurement campaign of the radio channel frequency response in an indoor scattered environment, we esteem the direction of arrival (DOA) of our signal, using MUSIC algorithm (multiple signal classification) associated with smoothing pre-processing and using MDL (minimum description length) approach proposed by Wax and Kailath for the detection of the number of multipath rays arrived at the antenna.

Assessing the integration of smart antenna systems in UMTS networks

This paper presents the methodology for the integration of smart antennas in UMTS networks. Preliminary results in a typical deployment scenario are provided. This contribution generalizes the methodology proposed by the authors in other works and provides new results on system-level parameters such as load factor and statistics for power dimensioning.

Frequency and time response of different polarization on indoor ISM band

The unlicensed Industrial Scientific and Medical (ISM) band at 2.4 GHz has gained increased attention recently due to the high data rate communication systems developed to operate in this band. The research presented in this work consists of measurement campaigns made in indoor environments of different polarization signals, to obtain frequency and time response of the radio channel.