Fast prototyping of an SDR WLAN 802.11b receiver for an indoor positioning system

Indoor positioning systems (IPS) are emerging technologies due to an increasing popularity and demand in location based service (LBS). Because traditional positioning systems such as GPS are limited to outdoor applications, many IPS have been proposed in literature. WLAN-based IPS are the most promising due to its proven accuracy and infrastructure deployment. Several WLAN-based IPS have been proposed in the past, from which the best results have been shown by so-called fingerprint-based systems. This paper proposes an indoor positioning system which extends traditional WLAN fingerprinting by using received signal strength (RSS) measurements along with channel estimates as an effort to improve classification accuracy for scenarios with a low number of Access Points (APs). The channel estimates aim to characterize complex indoor environments making it a unique signature for fingerprinting-based IPS and therefore improving pattern recognition in radio-maps. Since commercial WLAN cards offer limited measurement information, software-defined radio (SDR) as an emerging trend for fast prototyping and research integration is chosen as the best cost-effective option to extract channel estimates. Therefore, this paper first proposes an 802.11b WLAN SDR beacon receiver capable of measuring RSS and channel estimates. The SDR is designed using LabVIEW (LV) environment and leverages several inherent platform acceleration features that achieve real-time capturing. The receiver achieves a fast-rate measurement capture of 9 packets per second per AP. The classification of the propose IPS uses a support vector machine (SVM) for offline training and online navigation. Several tests are conducted in a cluttered indoor environment with a single AP in 802.11b legacy mode. Finally, navigation accuracy results are discussed

A Reduced Complexity Cross-correlation Interference Mitigation Technique on a Real-time Software-defined Radio GPS L1 Receiver

The U.S. global position system (GPS) is one of the existing global navigation satellite systems (GNSS) that provides position and time information for users in civil, commercial and military backgrounds. Because of its reliance on many applications nowadays, it's crucial for GNSS receivers to have robustness to intentional or unintentional interference. Because most commercial GPS receivers are not flexible, software-defined radio emerged as a promising solution for fast prototyping and research on interference mitigation algorithms. This paper provides a proposed minimum mean-squared error (MMSE) interference mitigation technique which is enhanced for computational feasibility and implemented on a real-time capable GPS L1 SDR receiver. The GPS SDR receiver SW has been optimized for real-time operation on National Instruments' LabVIEW (LV) platform in conjunction with C/C++ dynamic link libraries (DLL) for improved efficiency. Performance results of said algorithm with real signals and injected interference are discussed. The proposed SDR receiver gains in terms of BER curves for several interferers are demonstrated

GPS system implementation using software defined radio platform

Every day new technologies are being developed and introduced to the market, shaping people's daily life. The principal aim of our society is making up an ecosystem that provides anything, anytime, anywhere. For this purpose, more powerful and efficient devices, improved devices are being designed as the key ingredients. In this report it is shown the study and the implementation of a Global Positioning Service device, a technology that is used by more than four thousand millions of users. The present work explores the Global Positioning System development using a Software Radio Defined Platform. The implementation of this development is divided into four main parts: GPS signal acquisition and treatment carried out by the receptor, GPS received signal demodulation using Binary Phase Shift Keying, decoding through Direct Sequence Spread Spectrum of the previous demodulated signal, and finally, once the necessary data from the message was obtained, the position estimation. In order to perform all the process it was used as working tool a device known as Universal Software Radio Peripheral. This device allows for analysing from a visual point of view more accurate the four different phases explained previously. These phases represent the basis to be able to achieve the necessary knowledge about proper operation ot the Global Positioning System. The whole application was developd using LabVIEW software, a data ow visual programming language and environment designed by National Instruments.Cada día nuevas tecnologías son desarrolladas e introducidas en el mercado, modelando así la vida diaria de la sociedad. El principal objetivo de nuestra sociedad es conseguir crear un ecosistema que proporcione lo que sea necesario, en cualquier momento y en cualquier lugar. Para ello, equipos más potentes, eficientes y mejorados son diseñados como los ingredientes claves de este nuevo ecosistema. En este trabajo se presenta el estudio y la implementación de un receptor de señales GPS, tecnología que hoy en día es utilizada por más de cuatro mil millones de usuarios. Para ello se lleva a cabo el desarrollo del Sistema de Posicionamiento Global (GPS) mediante la utilización de una plataforma de radio definida por software. La implementación del desarrollo se divide en cuatro procesos principales: adquisición y el tratamiento de la señal GPS por parte del receptor, demodulación por desplazamiento de fase binaria (BPSK) de la señal GPS recibida, decodificación en espectro ensanchado por secuencia directa (DSSS) de la señal demodulada y por último, una vez obtenidos los datos necesarios del mensaje, la estimación de la posición. Para la realización de todo el proceso se utilizó como herramienta de trabajo un dispositivo conocido como Universal Software Radio Peripheral (USRP). Este aparato permite analizar desde un punto de vista visual más preciso las cuatro fases indicadas anteriormente. Estas fases suponen la base para lograr adquirir el conocimiento necesario sobre el funcionamiento del Sistema de Posicionamiento Global (GPS). El desarrollo completo de la aplicación fue implementado utilizando LabVIEW, un entorno de desarrollo integrado diseñado por la conocida compañía National Instruments.Ingeniería en Tecnologías de Telecomunicació

A Software Defined Radio based UHF Digital Ground Receiver System for Flying Object using LabVIEW

This study demonstrates the design and implementation of a software defined radio based digital ground receiver system using LabVIEW. In flight testing centre, command transmission system is used to transmit specific commands to execute some operation inside the flight vehicle. One ground receiver system is needed to monitor the transmitted command and monitor the presence of the command in air. The newly implemented ground receiver system consists of FPGA, RTOS and general processing unit. The analog to digital conversion and RF down conversions are carried out in high speed PCI extension for instrumentation express cards. The communication algorithms, digital down conversion are implemented in FPGAs. The communication system uses digital demodulation and decoding scheme and realised by NI PXI-7966R with Xilinx Virtex 5, SXT, FPGA. The performance of the receiver system has been analysed by linearity measurement of pre-amplifier Gain, Noise figure, frequency, power and also measurement of sensitivity. The results show successful implementation of the ground receiver system

Effectiveness of OPC for systems integration in the process control information architecture

A Process is defined as the progression to some particular end or objective through a logical and orderly sequence of events. Various devices (e.g., actuators, limit switches, motors, sensors, etc.) play a significant role in making sure that the process attains its objective (e.g., maintaining the furnace temperature within an acceptable limit). To do these things effectively, manufacturers need to access data from the plant floor or devices and integrate those into their control applications, which maybe one of the off the shelf tools such as Supervisory Control and Data Acquisition (SCADA), Distributed Control System (DCS), or Programmable Logic Controllers (PLC). A number of vendors have devised their own Data Acquisition Networks or Process Control Architectures (e.g., PROFIBUS, DEVICENET, INTERBUS, ETHERNET I/P, etc.) that claim to be open to or interoperable with a number of third party devices or products that make process data available to the Process or Business Management level. In reality this is far from what it is claimed to be. Due to the problem of interoperability, a manufacturer is forced to be bound, either with the solutions provided by a single vendor or with the writing of a driver for each hardware device that is accessed by a process application. Today\u27s manufacturers are looking for advanced distributed object technologies that allow for seamless exchange of information across plant networks as a means of integrating the islands of automation that exist in their manufacturing operations. OLE for Process Control (OPC) works to significantly reduce the time, cost, and effort required in writing custom interfaces for hundreds of different intelligent devices and networks in use today. The objective of this thesis is to explore the OLE for Process Control (OPC) technology in depth by highlighting its need in industry and by using the OPC technology in an application in which data from a process controlled by Siemens Simatic S7 PLC are shared with a client application running in LabVTEW6i

Development of an Integration Sensor and Instrumentation System for Measuring Crop Conditions

Precision agriculture requires reliable technology to acquire accurate information on crop conditions. Based on this information, the amount of fertilizers and pesticides for the site-specific crop management can be optimized. A ground-based integrated sensor and instrumentation system was developed to measure real-time crop conditions including Normalized Difference Vegetation Index (NDVI), biomass, crop canopy structure, and crop height. Individual sensor components has been calibrated and tested under laboratory and field conditions prior to system integration. The integration system included crop height sensor, crop canopy analyzer for leaf area index, NDVI sensor, multispectral camera, and hyperspectroradiometer. The system was interfaced with a DGPS receiver to provide spatial coordinates for sensor readings. The results show that the integration sensor and instrumentation system supports multi-source information acquisition and management in the farming field