基于GPS、GSM以及GIS技术的城市交通动态监控系统的设计及关键技术研究

随着城市交通日益繁忙，如何开发出一套定位精度高、价格低廉的车辆导航与定位系统，成为目前工TS（智能交通系统）中一个重要的研究部分。本文将GPS（全球定位系统）、GSM（全球移动通信系统）以及GIS（地理信息系统佩技术结合起来，开发出一套适合社会需求的车辆导航与定位系统，并对系统的设计、建立、系统功能、实现过程以及实验结果做了详尽的说明，提出了系统需要进一步改进的地方。系统总体工作的总体思路是使用安装在车辆上的GPS车载终端接收GPS卫星的定位信息、以GSM网络的短消息业务方式传回监控中心，在监控中心，GSM控制器将接收到的信息通过标准串口发送给监控计算机，监控计算机对信息、进行伪距一位置集中差分处理以及卡尔曼滤波，使定位精度由原来的100米左右提高到10米左右，然后使用集成地图的方法将其显示在地图上，以便作出合理的决策。

Sistema automático de medida usando o sistema GSM

Este artigo apresenta um sistema automático de aquisição de dados com aplicação na monitorização da qualidade da água, não só do mar mas também de rios, lagos e lagoas. É um instrumento ambiental bastante útil, baseado numa estação de medida situada numa bóia que envia os dados via GSM para uma estação em Terra.

Previsão de desempenho para redes móveis LTE e UMTS baseadas em redes GSM co-localizadas

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Electrónica e Telecomunicações

Estimação de cobertura rádio em GSM-R através de redes neuronais

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia de Eletrónica e Telecomunicações

A Multi-Mode Sigma-Delta ADC for GSM/WCDMA/ WLAN Applications

The demand for new telecommunication services requiring higher capacities, data rates and different operating modes have motivated the development of new generation multi-standard wireless transceivers. In multistandard design, sigma-delta based ADC is one of the most popular choices. To this end, in this paper we present cascaded 2-2-2 reconfigurable sigma-delta modulator that can handle GSM, WCDMA and WLAN standards. The modulator makes use of a low-distortion swing suppression topology which is highly suitable for wide band applications. In GSM mode, only the first stage (2nd order Σ-Δ ADC) is used to achieve a peak SNDR of 88dB with oversampling ratio of 160 for a bandwidth of 200KHz and for WCDMA mode a 2-2 cascaded structure (4th order) is turned on with 1-bit in the first stage and 2-bit in the second stage to achieve 74 dB peak SNDR with over-sampling ratio of 16 for a bandwidth of 2MHz. Finally, a 2-2-2 cascaded MASH architecture with 4-bit in the last stage is proposed to achieve a peak SNDR of 58dB for WLAN for a bandwidth of 20MHz. The novelty lies in the fact that unused blocks of second and third stages can be made inactive to achieve low power consumption. The modulator is designed in TSMC 0.18um CMOS technology and operates at 1.8 supply voltage

A Triple-Mode Feed-Forward Sigma-Delta Modulator Design For Gsm / Wcdma / Wlan Applications

This paper presents a cascaded 2-2-2 reconfigurable sigma-delta modulator that can handle GSM, WCDMA and WLAN standards. The modulator makes use of a low-distortion swing suppression topology which is highly suitable for wide band applications. In GSM mode, only the first stage (2nd order Σ-Δ ADC) is turned on to achieve 88dB dynamic range with oversampling ratio of 160 for a bandwidth of 200KHz; in WCDMA mode a 2-2 cascaded structure (4th order) is turned on with 1-bit in the first stage and 2-bit in the second stage to achieve 74 dB dynamic range with oversampling ratio of 16 for a bandwidth of 2MHz and a 2-2-2 cascaded MASH architecture with a 4-bit in the last stage to achieve a dynamic range of 58dB for a bandwidth of 20MHz. The novelty lies in the fact that unused blocks of second and third stages can be switched off taking into considerations like power consumption. The modulator is designed in TSMC 0.18um CMOS technology and operates at 1.8 supply voltage.

Sistema de localización mediante GSP y GSM aplicado al seguimiento y monitorización de personas con discapacidades físicas y mentales.

En este artículo se presenta un desarrollo cuya finalidad es poner a disposición de personas con discapacidad un servicio que les permita, ante situaciones de alarma enviar la información de su ubicación geográfica a un centro de control, a la vez que se les ofrece una comunicación de voz y también un seguimiento automático de su posición. Este servicio está pensado para aumentar el grado de autonomía de colectivos con discapacidades psíquicas, físicas o simplemente de personas mayores, que frente a una situación de indisposición, desorientación o pérdida puedan contactar con una mínima intervención con un centro de control.