International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Sensor technology is continually advancing to meet demands of a wide range of potential applications. Many of these applications could be better served by distributed sensing than by traditional centralized sensing. To support these emerging applications, it is important to design and develop a unified framework for communication and network infrastructure capable of supporting various sensing functions. A research prototype operating in the 915 MHz Industrial, Scientific, and Medical band (ISM band) has been developed as potentially the core component of this infrastructure. In this paper, we will present the design and optimization of the system, data processing procedures, system parameters, network protocols, and experimental results.

The Communications industry is currently involved in a wireless revolution. Consequently, there is a need for a wide variety of wireless solutions to replace existing wired systems. The major systems, such as cellular and satellite, are costly to put in place and require a low BER (bit error rate) to be successful for their real-time applications. In contrast to this are those systems that can tolerate a higher BER as a trade off for cost (<$50.00) and complexity. A typical application for these lower cost systems is monitoring non-critical data that is not required to be delivered real-time. The work presented here focused on designing, building and testing a Proof of Concept Prototype (POCP) for a low-cost wireless data link (WDL). In a typical WDL application, problems arise when too large a data rate attempts to travel the allotted channel bandwidth in the frequency band of interest. Also, limitations imposed by current radio transceiver technology tend to limit WDL design. The existing sponsor's wired system operates at a 9600 Baud, and presented the opposite problem: the data rate was too low for the RF Microdevices RF2905 used for the POCP. This challenge necessitated the development of a low-cost encoding scheme using standard digital logic gates in place of more costly Manchester Encoding. For the digital logic encoding scheme to work, the crystal oscillators had to be modified. This resolved the problem with the low frequency limitations of the RF2905 phase locked-loop. In addition, the polled, asynchronous, and unbalanced RS485 connections of the wired system had to be adapted to interface with the single-ended data connections of the WDL. Finally, the successful design of a timing scheme, using standard TTL components and balanced to unbalanced drivers, resolved the interface problems resulting in a low-cost WDL designed to operate with an existing wired system without requiring modifications to that system. The WDL is transparent in connection and operation and can be inserted without disrupting the current wired system. / Master of Science

This thesis includes two topics, which are a Self-sampled ALL-MOS ASK Demodulator and a Synchronous DAC with Self-calibration. An all-MOS ASK demodulator with a wide bandwidth for lower ISM band applications is presented in the first half of this thesis. The chip area is reduced without using any passive element. It is very compact to be integrated in an SOC (system-on-chip) for wireless biomedical applications, particularly in biomedical implants. Because of low area cost and low power consumption, the proposed design is also easily to be integrated in other mobile medical devices. The self-sampled loop with a MOS equivalent capacitor compensation mechanism enlarges the bandwidth, which is more than enough to be adopted in any application using lower ISM bands. To demonstrate this technique, an ASK demodulator prototype is implemented and measured using a TSMC 0.35 £gm standard CMOS process. The second topic reveals a synchronous DAC with self-calibration. The main idea is to use a calibration circuit to overcome large error of output voltage caused by the variation of the unit capacitor. When DAC is not calibrated, INL is larger than 1.7 LSB. After calibrated, INL is improved to be smaller than 0.5 LSB. To demonstrate this technique, a DAC prototype is implemented and measured using a TSMC 0.18 £gm standard CMOS process.

Cette thèse présente l’étude d’un réseau de capteurs pour la surveillance en temps réel de la qualité des eaux souterraines. L’objectif est de réussir à communiquer dans la bande de fréquences libre à 433MHz sur plusieurs dizaines de kilomètres. Le problème majeur des bandes libres est la présence de transmissions parasites (brouilleurs). Nous avons donc, en premier lieu, mis en évidence de la présence de ces brouilleurs et étudier leur impact sur les communications. Après analyse, il s’avère que les brouilleurs sont très nombreux et puissants mais que leur répartition dans la bande est inégale. Une étude spectrale de la bande semble nécessaire, avant la mise en place du réseau, afin de transmettre dans les canaux les moins pollués. Des communications nocturnes sont également à privilégier car les brouilleurs sont moins nombreux la nuit. Nous présentons ensuite une architecture réseau, adaptée au cahier des charges et à cette bande de fréquences. Nous avons également testé un composant RF dédié aux transmissions en bande ISM. Les résultats montrent que les performances de ce composant sont faibles pour des communications longues distances en présence de brouilleurs. Un récepteur radiofréquence simple ne permet donc pas de réaliser des communications fiables dans ces conditions. Le prototype complet du réseau, développé durant ces travaux, est ensuite décrit. Pour finir, nous proposons un nouveau concept de récepteur, utilisant un réseau d’antennes phasé et un détecteur cyclostationnaire, pour pallier au problème des brouilleurs. Le but est de stocker les signaux reçus pour les traiter en temps différé à l’aide d’algorithmes de filtrage spatial. Des simulations montrent l’efficacité de ce concept. / This thesis presents the study of a wireless sensor network for real-time monitoring of groundwater quality. The aim is to successfully communicate in the free 433MHz frequency band over tens of kilometers. The main issue of free bands is the presence of radio frequency interferences (RFI). First, we have studied the properties of these RFI and there impacts on communications. This analysis shows numerous and powerful jammers but with an irregular distribution in time and frequency. In consequence, the network set-up should be based on prior analysis of the time-frequency context. In particular, night communications should be preferred. Then, we present a network architecture adapted to the given industrial specifications and the mentioned frequency band constraint. We have also tested a RF component suitable for ISM band transmissions. Results show that the component performances are low for longue range communications with RFI. With a simple radio frequency receiver, reliable communications are not possible in these conditions. Then the complete network prototype, developed during this thesis, is described. Finally, to overcome the problem due to jammers, we propose a new receiver concept. It is based on a phased antenna array and a cyclostationary detector. The aim is to detect the signal of interest among RFI and to store it for further signal processing. In particular, off-line spatial filtering techniques can used to remove RFI. Simulations show the efficiency of this concept.

The aim of this master’s thesis is analysis of wireless communication between mikroprocesors. The first part of the work are analysed the problems the wireless free ISM band. Mainly RFM12B and ZigBee module, which i these band work and ZigBee standart. The second part are described relazation board for both module. Further how programming ZigBee module. And at last programs for tested module.

The wideband channel has been analyzed at the University of Gävle by using millimeter-wave (mm-Wave) frequency for improving the fifth-generation (5G) in Radio-frequency (RF) characterization. The proposed mm-Wave frequency is 24GHz, which is carried out from measurement testbed at the Robotics Lab. To explore the channel behaviors of the ISM band and mobile radio, three typically environments have been created inside of the Robotics Lab at the University of Gävle in which are Higher reflection (HR), natural reflection (NR), and Ultra reflection (UR). The relative motion of the transmitter (Tx) is carried out by adjoining the omnidirectional antenna to a KUKA robot's arm inside the Robotics lab at the University of Gävle, Sweden. The radio channel behavior is observed at different circumstances with two different movements of KUKA’s arm e.g., higher speed (2m/s) and slower speed (1m/s) for the Line of sight (LOS) and Non-Line of sight (NLOS) condition. We then achieve the time-varying power delay profile (PDP) and frequency-varying Doppler spectral density (DSD) from scattering components of the experiment environment. The Wide-band channel characteristics have been based on the (PDP) and (DSD), we analyze the root-mean-square of the (RMS) delay spread, RMS Doppler spread, Coherence time, Coherence bandwidth, and mean delay, Doppler shift from 24 different scenarios for behaviors of the mobile radio channels and indoor wireless application. / <p>Actually, My thesis title is '' A Study of Multipath Propagation and Doppler Effect at 24GHz ISM band''. I have generated mm-wave frequency from my testbed which is 24GHz. For better analysis, i was designed and created a Multipath environment inside of the  Robotics Lab at University of Gävle, I also used KUKA Robot and designed two diffrient motion for the Transmitter,such as ''C'' type and '' inverse ''type .</p>

In this paper, at the beginning, we focused our studies on the practical planar antenna designs for wireless communication. We also proposed several antenna designs operating at the widely used bands, such as the ISM, GSM, GPS, 3G bands and their combinations. For the antenna designs at these bands, the circularly polarized wide slot antenna and planar monopole antenna with the conducting plate loading for ISM band application, shorted stacked mircostrip antenna for 3G band application, and the low cost high gain 8&#x00CD;8 stacked patch array for dual ISM band application have been presented. To provide mobile communication and the accurate position of the user as well, the GSM/GPS dual-band antenna suitable for vehicle application is presented. Finally, the GSM/ISM dual-band antenna designed for the personal communication and wireless local area network is also shown. The performance we have achieved in these antenna designs not only satisfy the specific requirements of the system, but also show good antenna pattern, and gain.

This diploma thesis deals with the study and measurement of coexistence scenarios that can occur between the LTE and LoRa systems in the unlicensed ISM band 2.4 GHz. A common radio frequency band in which LTE and LoRa systems can coexist is defined. An appropriate laboratory measurement is proposed and realized, allowing automatized measurement of the defined coexistence scenarios. For this purpose, a personal computer, professional measurement equipment and software MATLAB are utilized. Functionality of the proposed concept is verified by extensive measurements. The obtained results are graphically shown and discussed in detail.

Wireless extension of serial communication of RS232 standard, with using RF transceivers RFM12BP type, with transmissions errors correction. Device will be batery powered and low power consumption is required.

This thesis deals with the design and the realization of the radiocommunication monitor for the 868 MHz band. In the thesis, a description of licence-free radio bands complying ITU recommendations and ETSI standards is given. A special attention is paid to the 863 MHz - 870 MHz band. The transceiver CC1020 that forms the base for the monitor is described in detail. The circuit design, the monitor assembly and the firmware creation are presented step by step. The radiocommunication monitor is portable and battery powered. The monitor is able to display RF signals in the 868 MHz band, to indicate the frequency error of the transmitter and to receive FSK modulated signal. Demodulated data can be transferred to the personal computer via the USB.