In recent years, the worldwide progress of wireless communication technology has bringing great benefit and convenience to our people¡¦s life. Nowadays, people can use appliances of wireless communication in many fields, such as family-monitoring, automatic system, and smart-type device¡Ketc. However, in order to dealing with the need of low cost and low power communication, the researcher spend many years on developing the specification of IEEE 802.15.4 Low Rate-Wireless Personal Area Network (LR-WPAN) expected be applied in widespread use. In this thesis, we focus on the baseband signal processing for the physical layer specification of the 868/915MHz mode of the IEEE 802.15.4 LR-WPAN. Our design blocks include packet detection, sampling point detection (energy detection), carrier frequency offset (CFO) compensation, carrier phase offset (CPO) compensation, and despreading algorithms. During the process of simulation, we¡¦ll examine whether our design match the criteria of standard such as sensitivity, packet format, and modulation. While our designs achieve the requirement of the standard, we start on quantization. Finally, we¡¦ll realize the algorithm in VHDL and examine it.

Thèse de doctorat : Informatique : INPL : 2007. / Titre provenant de l'écran-titre. Bibliogr.

Thèse doctorat : Informatique : Strasbourg 1 : 2006. / Titre provenant de l'écran-titre. Bibliogr. 9 p.

Thesis (M.S. in Computer Science)--Naval Postgraduate School, December 2003. / Thesis advisor(s): William J. Ray, Man-Tak Shing. Includes bibliographical references (p. 115). Also available online.

The potential end of Moore's law has caused the semiconductor industry to investigate 3D integrated circuits as a way to continue to increase transistor density. Solutions must be put in place to allow each 3D IC die layer to be tested thoroughly on its own at wafer level to unsure adequate yield on assembled 3D devices. This paper details the testability of a 3D implementation of the Open Cores or1200 architecture. IEEE 1500 is used to signi cantly improve wafer level testability of the 3D IC die layers while maintaining a low test pin count requirement. / text

Σκοπός της παρούσης διπλωματικής εργασίας είναι η προσομοίωση των λειτουργικών χαρακτηριστικών του ασύρματου δικτύου ΙΕΕΕ 802.16. Στο 1ο κεφάλαιο επιχειρείται μια εισαγωγή στην ασύρματη πρόσβαση ευρείας ζώνης. Στο 2ο κεφάλαιο γίνεται περιληπτική αναφορά στην εξέλιξη του WiFi, τον τρόπο λειτουργίας του και τη σημασία του ως πρόγονος του WiMAX. Στο 3ο κεφάλαιο γίνεται εισαγωγή στο WiMAX, τα διάφορα υποπρότυπα που κυκλοφορούν, τις τεχνολογίες που χρησιμοποιούν και σύγκριση με άλλες υπάρχουσες ασύρματες τεχνολογίες. Στο 4ο κεφάλαιο γίνεται σε βάθος εξερεύνηση του φυσικού στρώματος του WiMAX. Στο 5ο κεφάλαιο μελετούμε το στρώμα πρόσβασης μέσου του προτύπου. Στο 6ο κεφάλαιο αναλύουμε την αρχιτεκτονική του δικτύου WiMAX. Για το πρακτικό μέρος της διπλωματικής στο 7ο κεφάλαιο έγινε προσομοίωση του φυσικού στρώματος ενός ασύρματου ευρυζωνικού πομποδέκτη του υποπροτύπου IEEE 802.16-2004, με χρήση κεραιών ΜΙΜΟ, για σταθερή (fixed) πρόσβαση. Στο 8ο κεφάλαιο βρίσκονται τα συμπεράσματα από τις προσομοιώσεις. / --

The IEEE 802.15.4 standard defines the implementation of a Low-Rate Wireless Personal Area Network (WPAN). While the current version of the standard was ratified in 2006, there is still no readily available Medium Access Control (MAC) layer and/or Physical (PHY) layer for Altera Field Programmable Gate Arrays (FPGAs) in the public domain. This research investigates the implementation of the standard using an Altera FPGA for the MAC layer and PHY layer drivers. The Freescale MC13192 transceiver was used for the physical portion of the PHY layer, which includes the RF front end of the system. The purpose of this research was to implement a basic full function device (FFD), which is capable of acting as a node in the network, as well as co-ordinating it. This allows a simple network to be tested by loading the same code on two FPGA boards, with one configured to act as a coordinator and the other as a device. The flexibility of the standard means that there are several implementation choices to be made, each of which limits the compatibility with devices using other implementation options. The implementation and design decisions made in producing a preliminary core are described in detail. The implementation of the MAC layer primitives is discussed at length as these were not available as source code. These primitives are the building blocks for the core functions of the system. Specifically, the functionality of the Energy Detection (ED) scan, stream transmit and stream receive functions are explored in detail. The code has been implemented using C and is run on the Altera Nios II soft-core processor. The work presented here is an initial implementation meant to serve as a foundation for further research. Additional functionality defined by the standard could be added, or optimization of individual functions could be explored. The current implementation also has the potential to serve as the foundation for research into various sensors which may be part of end devices in the network.

This thesis investigates various aspects of bandwidth allocation and scheduling in the Medium Access Control (MAC) layer of IEEE 802.16 systems. We highlight the important aspects of designing a scheduler and describe the scheduler design problem from a general perspective. That is, we provide a scheduler design framework driven by a set of objectives defined for the systems. In addition, we include Subscriber Station differentiation into our scheduler design. This approach is comprehensive, as it covers the requirements of both the network provider and the end users. In developing the framework, we discuss the importance of achieving customer satisfaction. This leads to an interesting objective that maximises the number of satisfied customers, rather than network centric objectives, such as fairness. We contend that providing fairness to customers does not necessarily achieve the best outcome for customer satisfaction and artificially limits the choices available to service providers. In order to maximise the number of satisfied customers, we analyse in detail the Dual-Queue (DQ) scheduling discipline proposed by Hayes et al. [2]. The DQ algorithms of Hayes’ work are focused on wireline networks, and are not directly deployable in an 802.16 environment, as we discuss in this thesis. We propose a modified DQ implementation for 802.16 systems to handle real-time services. In 802.16 systems, there are two scheduling processes that we need to consider: Downlink (DL) scheduling for data transmission from the Base Station to the Subscriber Stations and Uplink (UL) scheduling for data transmission from the Subscriber Stations to the Base Stations. We investigate the DL and UL implementations separately because the UL scheduling process is more complicated due to the fundamentally distributed nature of the problem. We demonstrate that our proposed approach is able to operate effectively in an 802.16 system. We then compare the performance of our proposed DL and UL Dual- Queue schedulers to a Weighted Fair Queue scheduler in noisy environments, where re-transmissions are required. In addition, we also compare our proposed schedulers to an enhanced Weighted Fair Queue scheduler with an Explicit Packet Dropping mechanism. Furthermore, we show that our Dual-Queue system can handle mixed traffic profiles, such as video and voice. Having proposed a DQ implementation that maximises the number of satisfied customers, we investigate alternative objectives that the DQ scheduler may try to achieve. We find that our proposed DQ implementation may fail to achieve these alternative objectives, and hence, we remedy this shortfall by proposing the Priority- Based Dual-Queue scheduler, which is made up of multiple DQs differentiated by the priority classes of connections. That is, each priority class is handled in a separate DQ. The Priority-Based Dual-Queue scheduler ensures connections that belong to the highest priority class are served ahead of connections that belong to lower priority classes at all times, even when there are changes in the priority class of connections in the system. Lastly, we investigate the benefits of carrying out the DQ scheduling for both the DL and UL of an 802.16 network jointly. We first investigate a scenario where the network consists of only one-directional connections. We propose a joint scheme that is able to maximise the number of satisfied one-directional connections in the network. We then extend our investigation to another scenario where the network consists of bi-directional sessions, such as Voice over IP and video conferencing. In this case, we propose two joint schemes, which are able to maximise the number of satisfied bi-directional sessions. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1363601 / Thesis (Ph.D.) -- University of Adelaide, School of Electrical and Electronic Engineering, 2009

Thesis (M.S.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 49-50). Also available on the World Wide Web.

Thesis(M.S.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references (p.63-67).