<p>This work is focused on the CORDIC algorithm for wireless LAN. The primary task is to create a VHDL description for CORDIC vector rotation algorithm. </p><p>The basic research has been carried out in MATLAB. The VHDL implementation of the CORDIC algorithm is based on the results obtained from the MATLAB simulation. Mentor Graphics FPGA Advantage© for Xilinx 4010XL FPGA has been used for the hardware implementation.</p>

Large-scale deployment of IEEE 802.11 wireless LANs (WLANs) remains a significant challenge. Many access points (APs) must be deployed and interconnected without a-priori knowledge of the demand. We consider that the deployment should be iterative, as follows. At first, access points are deployed to achieve partial coverage. Then, usage statistics are collected while the network operates. Overloaded and under-utilized APs would be identified, giving the opportunity to relocate, add or remove APs. In this thesis, we propose extensions to the WLAN architecture that would make our vision of iterative deployment feasible. One line of work focuses on self-configuration, which deals with building a WLAN from APs deployed without planning, and coping with mismatches between offered load and available capacity. Self-configuration is considered at three levels. At the network level, we propose a new distribution system that forms a WLAN from a set of APs connected to different IP networks and supports AP auto-configuration, link-layer mobility, and sharing infrastructure between operators. At the inter-cell level, we design a load-balancing scheme for overlapping APs that increases the network throughput and reduces the cell delay by evenly distributing the load. We also suggest how to reduce the handoff time by early detection and fast active scanning. At the intra-cell level, we present a distributed admission control that protects cells against congestion by blocking stations whose MAC service time would be above a set threshold. Another line of work deals with self-deployment and investigates how the network can assist in improving its continuous deployment by identifying the reasons for low cell throughput. One reason may be poor radio conditions. A new performance figure, the Multi-Rate Performance Index, is introduced to measure the efficiency of radio channel usage. Our measurements show that it identifies cells affected by bad radio conditions. An additional reason may be limited performance of some AP models. We present a method to measure the upper bound of an AP’s throughput and its dependence on offered load and orientation. Another reason for low throughput may be excessive distance between users and APs. Accurate positioning of users in a WLAN would permit optimizing the location and number of APs. We analyze the limitations of the two most popular range estimation techniques when used in WLANs: received signal strength and time of arrival. We find that the latter could perform better but the technique is not feasible due to the low resolution of the frame timestamps in the WLAN cards. The combination of self-configuration and self-deployment enables the autonomic operation of WLANs.

Cooperative traffic safety applications such as lane change or overtaking assistance have the potential to reduce the number of road fatalities. Many emerging traffic safety applications are based on IEEE 802.11p and periodic position messages, so-called cooperative awareness messages (CAM) being broadcasted by all vehicles. In Europe, ETSI defines a periodic report rate of 2 Hz for CAMs. Although a high report rate is the key to early hazard detection, the 2 Hz rate has been chosen to avoid congestion in settings where the vehicle density is high, e.g., on major highways and in urban scenarios. However, on rural roads with a limited number of communicating vehicles, a report rate of 2 Hz leads to unnecessary delay in cooperative awareness. By adapting the CAM report rate depending on the specific application and road traffic density, and by making use of the priority levels provided by the 802.11p quality of service mechanism, we show that hazards can be detected earlier and the available bandwidth is used more efficiently, while not overexploiting the network resources. / <p>©2011 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.</p><p></p><p>Category number CFP11VTF-ART; Code 87844</p>

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This dissertation focuses on the problem of providing mechanisms for routing point to point and multipoint connections in ATM networks. In general the notion of multipoint connection refers to connections that involve a group of users with more than two members. The main objective of this dissertation is to contribute to design efficient routing protocols with alterative routes in fully connected VP-based ATM Networks for call establishment of point to point and multipoint VC connections. An efficient route should be computed during this connection establishment phase.

The result of this master thesis report describes the advantages and the drawbacks that will arise when implementing an Ethernet based intercommunication system in military vehicles. The report presents a possible solution and describes how different sound applications will be implemented into the suggested solution. The report show that IP LAN in vehicles leads to more advantages than drawbacks. The main advantages are that all kind of media can share the same LAN and that there is a lot of knowledge of this technique in the civil area. The main drawback is about delay. The drawbacks are otherwise well known and methods are known to decrease the impact of them. In the suggested intercommunication system the processing delay gives the largest impact on not deliver data in real time. The suggested solution, with separate connections for intercom unit and PC platform to the switch at each crew member gives good reliability and security.

This work is focused on the CORDIC algorithm for wireless LAN. The primary task is to create a VHDL description for CORDIC vector rotation algorithm. The basic research has been carried out in MATLAB. The VHDL implementation of the CORDIC algorithm is based on the results obtained from the MATLAB simulation. Mentor Graphics FPGA Advantage© for Xilinx 4010XL FPGA has been used for the hardware implementation.

Att konstruera ett tidtagningssystem för enduro i skogen leder till flera frågor som måste undersökas och besvaras. Vilken kommunikationsteknik ska användas och vilken systemarkitekturisk lösning passar bäst? Att dra kabel ute i skogen är ett bra sätt att lösa det kommunikationstekniska problemet, lösningen är säker och relativt billig. Visst påverkas priset av distansen mellan olika klienter ute i skogen, men alla positiva egenskaper hos tekniken gör denna kostnad värd sitt pris. De geografiska variationer som kan finnas är de som kan spela ut de övriga teknikerna i form av stabilitet. En snabb resultatförmedling kräver ett system som har en väl uppbyggd systemarkitektur. Vid tidtagning kommer data i form av tider skickas från klienterna direkt till huvudservern, ingen mellanlagring sker utan data lagras centralt vilket förespråkas i IRM. Dessutom kommer ingen redundans att accepteras, vilket även det förespråkas av IRM. Det finns även flera andra parametrar som väger för att välja IRM, vilket är det som rekommenderas utifrån den analys som gjorts i denna uppsats.

Along with the rise of smart phones, Google announced a mobile platform named Android, having the advantages of open source, free, etc, had become one of the popular mobile development platforms. But there are following restrictions on the file sharing of the smart phones: 1. The File Sharing between mobiles is used frequently, but the APP of the File Sharing in Google play contains user sharing their files on the same LAN, can¡¦t share on the WAN. 2. The cloud storage space has the file sharing strategy on WAN, but doesn¡¦t on LAN. 3. File sharing of mobile devices always hope to be able to share file through one-to-many Push, delivery to the nearby users but the app of the smart phone file sharing don¡¦t have this function. Therefore, this thesis architects a File Sharing platform, which is based on social networks, passing through pub/sub pattern to sharing files.In the File Sharing System, if users are on the same LAN can share files directly. We implement one-to-many file sharing system, so that users can obtain files automatically. If on the WAN, files are delivered by the intermediary server. This System also supports Multimedia streaming, users can play media from Server; need not download files in the local device. This paper use protocol buffer to the communication between devices, compared with the current common XML, JSON and other common file formats, there is a better package rates and privacy, and provides a convenient user interface to share files.

This thesis proposes a variety of antenna designs suitable for modern of mobile products, such as mobile phones, PDAs and so forth, on both the 2G and 3G communication systems according to the mobile communication development. Based on the integration of monopole or planar inverted-F antenna with the system ground planes, multi-frequency, broadband, and high radiation efficiency can be achieved, which is very promising to be adapted into communication products. Furthermore, an antenna capable of WLAN and UWB is proposed for future wireless communication applications.