VII International Telecommunications Symposium

Tomography is a non-invasive exam technique that provides a great amount of visual information of virtually inaccessible areas of the body. This paper analyses the quality of a set of tomographic images taken with different irradiated power, controlled by current value, searching for the smaller current that can provide sufficient quality images.

The Texas eZ430-RF2500 is a new device developed for wireless networking applications. This paper analyzes the propagation features of this device for the several operating modes.

Gunshot detection finds application in the fields of law enforcement, forensic science, and defense (military applications). The first task of a sniper detector, aiming to estimate the direction of arrival of a given gunshot, is to detect automatically the presence of this audio event. Since it is a typical on-line application where a fast response...

Documents digitalized by portable cameras or flatbed scanners may exhibit some blurred areas. Most deblurring algorithms are hard to implement and slow. Often they try to solve the problem for any kind of image. In the case of text document images, the transition between characters and the paper background has a high contrast. With that in mind, a...

We propose a new method to model the effect of finite-precision arithmetic in infinite impulse response (IIR) digital filters. As an application, we use the proposed model to compute the probability of saturation or overflow in IIR filters implemented in fixed-point arithmetic. The transition from the current filter output to the next output is...

The purpose of this paper is to evaluate the performance of fixed-WiMAX (IEEE 802.16-2004) operating in seven propagation channel models, by implementing a WirelessMAN-OFDM physical layer simulator. Through comparative analysis of BER and throughput, the performance of the specified modulation and coding schemes and adaptive control actions were...