L. de Haro Ariet

Capacity and interference statistics of highways W-CDMA cigar-shaped microcells (uplink analysis)

The capacity and the interference statistics of the sectors of the shaped W-CDMA cell are studied. A model of five cells is used to analyze the uplink. The cells are assumed to exist in rural zones. The capacity and the interference statistics of the cell are studied using a two-slope propagation model. The expected value and the variance of the interference are given for different propagation exponent.

Comments on the hybrid model for propagation loss prediction in tunnels

The hybrid model for propagation-loss prediction in tunnels is discussed and its limitations are given. The values from the waveguide model with /spl gamma//sub 2/<2 are applicable for only short distances and for tunnels with low specific attenuation factor (/spl alpha/). In general, /spl gamma//sub 2/ can take any value higher than two.

Preliminary analysis of the calibration procedures for a geodesic antenna array (GEODA)

In this contribution, we have presented a preliminary analysis for the implementation of the calibration algorithm to a geodesic antenna array (GEODA) and propose a new algorithm for the on-line calibration. Some simulations was presented in order to allow us explain the scope of this project and the importance of compensate the errors presented at the uncalibrated antenna.

Implementation of a setup module for a plug-and-play UMTS smart antenna

Although UTRA-UMTS foresees smart antennas operation, they have not been applied yet, due to their complexity and cost. This paper describes the implementation of a smart antenna prototype, focusing on the set-up module that allows the system to have a transparent behaviour regarding the Node-B. The implemented set-up module identifies the new users in the system, and it obtains the parameters that are needed by other processing modules. This paper describes the implemented steps for the identification and acquisition of user data. Furthermore, the results for a real time implementation in a DSP platform are presented, showing that the data are properly obtained and real time requirements are fulfilled

On the capacity and interference statistics of street W-CDMA cross-shaped micro cells in Manhattan environment (uplink analysis)

The capacity and the interference statistics of the sectors of the shaped W-CDMA cell are studied. A model of 17 cells is used to analyze the uplink. The cells are assumed to be those of Manhattan like streets. The capacity and the interference statistics of the sectors are studied for different sector ranges, and different side lobe levels of base station antenna pattern.

Microcellular propagation modeling including antenna pattern and polarization

In digital radio channels, where multipath propagation takes place, antenna polarization and radiation pattern influence important channel parameters such as the received power and the delay spread. To study these effects in an urban microcellular propagation environment, a ray tracing three dimensional model has been developed. The buildings and ground are characterized as dielectric planar surfaces. Each ray can suffer multiple reflections and/or diffractions that are analyzed using geometrical optics and the uniform theory of diffraction (UTD). Both transmitter and receiver antenna patterns and polarization are included in the model. This requires to calculate the electric field direction along the whole ray tracing process.In digital radio channels, where multipath propagation takes place, antenna polarization and radiation pattern influence important channel parameters such as the received power and the delay spread. To study these effects in an urban microcellular propagation environment, a ray tracing three dimensional model has been developed. The buildings and ground are characterized as dielectric planar surfaces. Each ray can suffer multiple reflections and/or diffractions that are analyzed using geometrical optics and the uniform theory of diffraction (UTD). Both transmitter and receiver antenna patterns and polarization are included in the model. This requires to calculate the electric field direction along the whole ray tracing process.

Statistical characterization of the antenna and wireless multipath virtual channel interaction

The proposed procedure allows us to remark easily the interaction between the antenna and the simulated channel. The procedure not only permits to simulate the interaction between ideal antennas and channels but it could make to interact real antennas with the simulated channel by using a file with measured pattern. Moreover, it is applicable to evaluate radiation systems orientated to MIMO (multiple input and multiple output), because it allows the calculation of the spatial correlation of the different types of antennas with virtual ratio channels. In the case of real antennas, in the lack of the file of the measurements of their directional characteristics, the same results can be obtained from approximately through electromagnetic simulation. Then you can use the program MatLab to obtain the behavior of a real antenna in a dispersive environment.

OFDM-MIMO system using optimized differential Cayley unitary space time coding

In this paper, we optimize the OFDM-MIMO system using Cayley differential unitary space-time coding. The overall system combines the advantages of the OFDM modulation, MIMO channel and Cayley codes. A high transmission rate is one of the main advantages of the Cayley code, in addition to the simplicity of the encoder-decoder design, without the need for channel information. The mapping parameters and the basis matrices are the main components of the Cayley code. The optimization process of the Cayley code, with respect to the mapping parameters, is performed for the MIMO channel model represented by the downlink from a base station (BS) to a given user, with the scatterers arranged in the form of circular rings around the transmitter and the receiver.

The overlay of intelligent FDSS system on N-CDMA system

The capacity gain of a frequency diversity spread spectrum system (FDSS) overlaid on top of a narrowband code division multiplexing access (N-CDMA) system is estimated. The carrier to interference ratios (CIR) of both the FDSS and N-CDMA systems are evaluated. It is assumed that the base stations of both systems are unilocated and that the power control of the uplink and downlink of both systems is imperfect. The number of the FDSS users that can be overlaid on the N-CDMA system is 140 low bit rate users (9.6 kbit/sec.) or 11 data users (144 kbit/sec.).