Because using the perfect orthogonal code in CDMA system means elimination of multi-path interference and multiple access interference, we will discuss this aspect in this thesis. At first, we address a algorithm to how to search a flock of perfect orthogonal code, which consisting of many codes have a characteristic of perfect auto-correlation and perfect cross-correlation to each other. Following, we will compare perfect orthogonal code we find with the present complementary codes include complete complementary code (CCC), super complementary code (SCC), and two-dimensional orthogonal variable spreading code (2D-OVSF code). Considering that the run time of searching perfect orthogonal code is long in case of high processing gain (PG), we construct a PC cluster based Linux O.S or Windows O.S for the operation of parallel program to faster our production of perfect orthogonal code.

Das HERA-$B$-Experiment am Deutschen Elektronen-Synchrotron (DESY) in Hamburg dient der Untersuchung der Physik von Teilchen, die $b$-Quarks enthalten. Der Schwerpunkt des Ex\-pe\-ri\-mentes liegt auf der Messung der CP-Verletzung im System der neutralen $B$-Mesonen. Es wird erwartet, dass die pr\"azise Bestimmung der CP-Asymmetrie im Zerfallskanal $B^0(\bar{B}^0)\to J/\psi K_S^0$ gro{\ss}en Einfluss auf die Weiterentwicklung des Standardmodells der Elementarteilchenphysik und g\"angiger kosmologischer Theorien haben wird. Das HERA-$B$-Experiment nutzt den Protonenstrahl des HERA-Ringes, um in Kollisionen mit einem feststehenden Target paarweise $B$-Hadronen zu erzeugen. Die Wechselwirkungen werden in einem Vorw\"artsspektrometer mit etwa 600.000 Auslesekan\"alen nachgewiesen. Aufgrund der relativ niedrigen Schwerpunktsenergie von 41.6\,GeV sind Ereignisse mit $b$-Quarks im Vergleich zu Wechselwirkungen mit leichteren Quarks um etwa sechs Gr\"o{\ss}enordnungen unterdr\"uckt. Die Selektion von Signalereignissen stellt daher eine besondere Herausforderung dar. Sie wird von einem vierstufigen Datennahme- und Triggerystem \"ubernommen, das die Ereignisrate von 10\,MHz auf etwa 20\,Hz reduziert. Neben speziell entwickelter Elektronik werden im Triggersystem mehrere hundert handels\"ubliche PCs eingesetzt. Die Computer sind in zwei so genannten PC-Farmen mit jeweils mehr als 200 Prozessoren angeordnet, die die Rechenkapazit\"at f\"ur Triggerentscheidungen und die prompte Analyse der Ereignisdaten zur Verf\"ugung stellen. Auf der einen Farm laufen schnelle Triggerprogramme mit einer Rechenzeit von etwa 1--100\,ms pro Ereignis ab. Die andere Farm rekonstruiert die Ereignisse online, bevor die Daten auf Band dauerhaft archiviert werden. Die pro Ereignis aufgewandte Rechenzeit liegt dabei im Bereich einiger Sekunden. Die vorliegende Arbeit behandelt zwei Themenkreise. Einerseits wird die technische Umsetzung der Trigger- und der Rekonstruktionsfarm beschrieben. Besonderes Augenmerk liegt dabei auf den Software-Systemen, die den Farmen erforderliche Kalibrationsdaten verf\"ugbar machen und die zentrale \"Uberwachung der Ergebnisse der ablaufenden Programme gestatten. Der Hauptteil der Arbeit besch\"aftigt sich mit Algorithmen f\"ur eine dritte Triggerstufe, die zus\"atzlich zu existierenden Programmen auf der Triggerfarm zum Einsatz kommen sollen. Der Zerfall $B^0(\bar{B}^0)\to J/\psi X$ hat eine sehr klare Signatur, wenn das $J/\psi$ in ein $e^+e^-$- oder $\mu^+\mu^-$-Paar zerf\"allt. Im Triggersystem wird nach einem Paar entgegengesetzt geladener Leptonen des gleichen Typs gesucht, deren invariante Masse der des $J/\psi$ entspricht und deren Spuren von einem gemeinsamen Vertex in der N\"ahe des Targets ausgehen. Es wird davon ausgegangen, dass die Ausnutzung aller kinematischen Zwangsbedingungen ausreicht, um diesen Zerfallskanal klar von Untergrundereignissen zu trennen. Die dritte Triggerstufe soll dagegen auf Signalprozesse mit weniger kinematischen Beschr\"ankungen angewandt werden. Solche Ereignisse entstehen zum Beispiel dann, wenn zwei in der Proton-Target-Kollision erzeugte $B$-Mesonen semileptonisch zerfallen. Das Triggersystem selektiert lediglich die beiden Leptonen, die aber hier nicht von einem gemeinsamen Vertex kommen. Die dritte Triggerstufe soll f\"ur derartige Zerfallstopologien innerhalb von 100\,ms pro Ereignis weitere Kriterien zur Unterscheidung von Signal- und Untergrundprozessen aus den Daten extrahieren. In der Arbeit wird anhand von Monte-Carlo-Studien untersucht, inwieweit die Daten des Silizium-Vertexdetektors des Experimentes zur Entscheidungsfindung einer dritten Triggerstufe beitragen k\"onnen. Dabei wird die Rekonstruktion von Spuren aus der Zerfallskaskade der $B$-Hadronen zus\"atzlich zu den von der vorhergehenden Triggerstufe selektierten Lep\-ton\-en an\-ge\-strebt. Mithilfe einer schnellen Mustererkennung f\"ur den Vertexdetektor wird gezeigt, dass das Auffinden aller Spuren und die Anwendung von Triggeralgorithmen innerhalb des vorgegebenen Zeitfensters von 100\,ms m\"oglich sind. Die Bestimmung der Spurparameter nahe der Targetregion macht von der Methode des Kalman-Filters Gebrauch, um der Vielfachstreuung im Detektormaterial Rechnung zu tragen. Dabei tritt das Problem auf, dass weder der Impuls der gefundenen Spuren bekannt ist, noch die Materialverteilung im Vertexdetektor aus Zeitgr\"unden in aller Strenge ber\"ucksichtigt werden kann. Durch geeignete N\"aherungen gelingt es, eine ausreichende Genauigkeit f\"ur die Spurparameter zu erreichen. Die aufgefundenen Teilchen bilden den Ausgangspunkt f\"ur Triggeralgorithmen. Hierbei wird untersucht, welche Methoden am besten geeignet sind, um Signal- und Unter\-grund\-ereignisse voneinander zu trennen. Es erweist sich, dass das Auffinden von Spuren mit gro{\ss}em Impaktparameter aussichtsreichere Ans\"atze als eine Suche nach Sekund\"arvertices bietet. / The HERA-$B$ experiment at Deutsches Elektronen-Synchrotron (DESY) Hamburg aims at investigating the physics of particles containing $b$ quarks. The experiment focusses on measuring CP violation in the system of neutral $B$ mesons. It is expected that the precise determination of the CP asymmetry in the channel $B^0(\bar{B}^0)\to J/\psi K_S^0$ will have an impact on the further development of the Standard Model of Elementary Particle Physics and cosmological theories. The HERA-$B$ experiment uses the proton beam of the HERA storage ring in fixed-target mode. $B$ hadrons are produced in pairs when protons from the beam halo interact with target nuclei. The interactions are recorded by a forward-spectrometer with roughly 600.000 readout channels. At the HERA-$B$ centre-of-mass energy of 42.6\,GeV, the $b\bar{b}$ cross section is only a tiny fraction of the total inelastic cross section. Only one in about 10$^6$ events contains $b$ quarks, which turns the selection of signal events into a particular challenge. The selection is accomplished by a four-stage data acquisition and trigger system reducing the event rate from 10\,MHz to about 20\,Hz. Besides custom-made electronics, several hundreds of PCs are used in the trigger system. The computers are arranged in two so-called PC farms with more than 200 processors each. The PC farms provide the computing capacity for trigger decisions and the prompt analysis of event data. One farm executes fast trigger programs with a computing time of 1--100\,ms per event. The other farm performs online reconstruction of the events before data are archived on tape. The computing time per event is in the range of several seconds. This thesis covers two topics. In the beginning, the technical implementation of the trigger and the reconstruction farm are described. In doing so, emphasis is put on the software systems which make calibration data available to the farms and which provide a centralised view on the results of the executing processes. The principal part of this thesis deals with algorithms for a Third Level Trigger. This trigger is to come into operation on the trigger farm together with existing programs. Processes of the type $B^0(\bar{B}^0)\to J/\psi X$ have a very clean signature when the $J/\psi$ decays to a $e^+e^-$ or $\mu^+\mu^-$ pair. The trigger system attempts to identify two unlike-sign leptons of the same flavour whose invariant mass matches the $J/\psi$. In later steps, the tracks are required to originate from a common vertex close to the target. It is assumed that these kinematic constraints are sufficient to pick out events of this type among the copious background processes. In contrast, the Third Level Trigger is to be applied to signal processes with fewer kinematic constraints. Such events occur for example when two $B$ mesons, which were created in a proton-target collision, decay semileptonically. The trigger system selects merely the two leptons which do not originate from a common vertex in this case. The Third Level Trigger has 100\,ms at its disposal to extract further criteria from the data which can serve to distinguish between signal and background events. This thesis investigates with the aid of Monte-Carlo simulations how the data of the experiment's silicon vertex detector can contribute to the decisions of a Third Level Trigger. The trigger aims at reconstructing tracks from the decay cascade of $B$ mesons in addition to the leptons selected by the preceding trigger levels. A fast pattern recognition for the vertex detector demonstrates that the reconstruction of all tracks and the application of trigger algorithms are possible within the given time slot of 100\,ms. The determination of track parameters in the target region exploits the Kalman-filter method to account for the multiple scattering of particles in the detector material. The application of this method is, however, made difficult by two facts. First, the momentum of the reconstructed tracks is not known. And, second, the material distribution in the detector cannot be taken into consideration in detail due to timing limitations. Adequate approximations for the momentum and the material traversed by a particle help to accomplish a sufficient accuracy of the track parameters. The reconstructed tracks constitute the starting point of several trigger algorithms, whose suitability to select signal events is investigated. Our studies indicate that the reconstruction of tracks with large impact parameters is a more promising approach than a search for secondary vertices.

The present work introduces a methodology to obtain a discrete time state space representation of an electrical network using the nodal [G] matrix of the Electromagnetic Transients Program (EMTP) solution. This is the first time the connection between the EMTP nodal analysis solution and a corresponding state-space formulation is presented. Compared to conventional state space solutions, the nodal EMTP solution is computationally much more efficient. Compared to the phasor solutions used in transient stability analysis, the proposed approach captures a much wider range of eigenvalues and system operating states. A fundamental advantage of extracting the system eigenvalues directly from the EMTP solution is the ability of the EMTP to follow the characteristics of nonlinearities. The system's trajectory can be accurately traced and the calculated eigenvalues and eigenvectors correctly represent the system's instantaneous dynamics. In addition, the algorithm can be used as a tool to identify network partitioning subsystems suitable for real-time hybrid power system simulator environments, including the implementation of multi-time scale solutions. The proposed technique can be implemented as an extension to any EMTP-based simulator. Within our UBC research group, it is aimed at extending the capabilities of our real-time PC-cluster Object Virtual Network Integrator (OVNI) simulator.

The present work introduces a methodology to obtain a discrete time state space representation of an electrical network using the nodal [G] matrix of the Electromagnetic Transients Program (EMTP) solution. This is the first time the connection between the EMTP nodal analysis solution and a corresponding state-space formulation is presented. Compared to conventional state space solutions, the nodal EMTP solution is computationally much more efficient. Compared to the phasor solutions used in transient stability analysis, the proposed approach captures a much wider range of eigenvalues and system operating states. A fundamental advantage of extracting the system eigenvalues directly from the EMTP solution is the ability of the EMTP to follow the characteristics of nonlinearities. The system's trajectory can be accurately traced and the calculated eigenvalues and eigenvectors correctly represent the system's instantaneous dynamics. In addition, the algorithm can be used as a tool to identify network partitioning subsystems suitable for real-time hybrid power system simulator environments, including the implementation of multi-time scale solutions. The proposed technique can be implemented as an extension to any EMTP-based simulator. Within our UBC research group, it is aimed at extending the capabilities of our real-time PC-cluster Object Virtual Network Integrator (OVNI) simulator.

The present work introduces a methodology to obtain a discrete time state space representation of an electrical network using the nodal [G] matrix of the Electromagnetic Transients Program (EMTP) solution. This is the first time the connection between the EMTP nodal analysis solution and a corresponding state-space formulation is presented. Compared to conventional state space solutions, the nodal EMTP solution is computationally much more efficient. Compared to the phasor solutions used in transient stability analysis, the proposed approach captures a much wider range of eigenvalues and system operating states. A fundamental advantage of extracting the system eigenvalues directly from the EMTP solution is the ability of the EMTP to follow the characteristics of nonlinearities. The system's trajectory can be accurately traced and the calculated eigenvalues and eigenvectors correctly represent the system's instantaneous dynamics. In addition, the algorithm can be used as a tool to identify network partitioning subsystems suitable for real-time hybrid power system simulator environments, including the implementation of multi-time scale solutions. The proposed technique can be implemented as an extension to any EMTP-based simulator. Within our UBC research group, it is aimed at extending the capabilities of our real-time PC-cluster Object Virtual Network Integrator (OVNI) simulator. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate