The competitions of communication systems are more drastic with the advance and implement of 3G communication systems. Because 3G communication systems can support many serves, it is necessary to provide communication quality. We will discuss the W-CDMA of 3G communication systems in this paper, and research the modify method for cell search on the environment of mutipath or muticell. Because the cell search will be affected by the communication channel, it will produce the error of received signals, long cell search time and low working efficient. Thus, we propose an interference cancellation in the original system. The proposed system can strengthen the received signal and cancel the interference of signals. It also can reduce the cell search time and accelerate the searching speed.

Cell search of Third Generation Partnership Project Long Term Evolution (3GPP LTE) includes time synchronization and frequency synchronization of frames, and the acquisition of Cell Identity (Cell ID). The LTE systems use 504 Cell IDs divided into 168 unique Cell-Identity Groups (Cell-ID Groups), and each Cell-ID Group comprises three Sector Identities (Sector IDs). After reaching synchronization of time and frequency between frames, the Cell ID acquisition scheme provided by specification of 3GPP LTE is consisted of two steps, the first step must utilize three matched filters to detect one out of three Sector IDs, and then implement coherent correlation detection between 168 Pseudo Random Noise Sequences (PN sequences) to obtain the index of Cell-ID Group. So the cell search scheme provided by LTE standard has to detect correlation of all sequences, and computed complexity brings considerable processing time to effect the delay time of services power on, standby time, energy saved, and cost of manufacture. To reduce complexity, we propose a perfect sequence with special structure as preamble, and the sequence is linear combination of two base sequences. We put the sequences within Primary Synchronization Channel (P-SCH) and Secondary Synchronization Channel (S-SCH), and we utilize the phase rotation factors of the sequences as index to generate Cell ID, instead of the current scheme to generate Cell ID with the indexes between sequences and sequences. Based on the sequences in multipath channel model, simulation results verify the detection probability of Cell IDs by proposed scheme is 100% when SNR is -8dB, and it is 98.7% by the scheme in LTE specification after perfect time and frequency compensation. Except that, Cell ID detection performance is similar without channel compensation to reduce implement complexity. Index Terms- cell search, 3GPP LTE, 16n perfect sequence.

Par définition, une métastase est la formation de foyers tumoraux secondaires liée à la capacité des cellules tumorales à se détacher de la tumeur primitive, de s’implanter dans un autre organe et de proliférer. A partir du foyer primitif, il peut y avoir une dissémination micrométastatique c’est-à-dire la libération dans le sang ou le réseau lymphatique de cellules tumorales isolées ou de petits amas cellulaires. Ces micrométastases peuvent proliférer et donner naissance à des métastases. La difficulté est de déceler ces cellules tumorales isolées ou en micro-amas, et également d’évaluer leur valeur pronostique, ainsi que leur potentiel métastatique. Dans cette étude, nous allons nous intéresser plus particulièrement au processus métastatique lié à l’acte chirurgical dans les cancers epdermoïde des voies aérodigestive supérieures (CEVADS). En effet, dans ce type de cancers, la meilleure méthode pour établir un diagnostic est l’analyse anatomo-pathologique du prélèvement réalisé par biopsie. La principale barrière physique empêchant les cellules tumorales de migrer est la membrane du tissu atteint. Lors de la chirurgie, ces barrières sont détruites, ce qui facilite l’invasion du système vasculaire. Les cellules tumorales peuvent ainsi se loger dans les vaisseaux et proliférer à distance du site primitif pour former des tumeurs secondaires. Généralement, les métastases sont détectées par imagerie ou sérologie à un stade très avancé du cancer. L’objectif de cette étude est de détecter la présence de cellules isolées ou disséminées (CTCs) de CEDVADS dans la circulation sanguine a travers trois axes de recherche des métastases : 1) Étude des marqueurs moléculaires pour le diagnostic d’envahissement ganglionnaire des carcinomes épidermoïdes des voies aérodigestives supérieures réalisée par PCR quantitative en temps réel et en OSNA. 2) Recherche des cellules tumorales disséminées dans les drains de Redon après curage cervical 3)Recherche des cellules tumorales circulantes après acte chirurgical pour carcinomes épidermoïdes des VADS stade III et IV. Ce protocole nous permettra de valider la recherche des CTCs en situation clinique et par la suite de développer des études prospectives diagnostiques et pronostiques des CTCs des CEVADS / Metastasis is defined as the development of secondary tumor sites related to the ability of tumor cells to detach from primary tumor, to implant in another organ and to proliferate. From the primary site, a micrometastatic dissemination can occur through the release in blood stream or lymph system of isolated tumor cells or of small cell clusters. These micrometastases can proliferate and grow into metastases. The detection of isolated or microclustered tumor cells, the evaluation of the prognosis value, and their metastatic potential encounter difficulties. In this study, we focused mainly on the metastatic process related to surgery in epidermoid cancers of the upper aerodigestive tract (…). Indeed, in this type of cancers, the best method to establish diagnosis is the biopsy assessed by the anatomo-pathological analysis of a sample. The main physical barrier preventing cells from migrating is the membrane of the malignant tissue. During surgery, these barriers are destroyed, facilitating the invasion of the vascular system. Therefore tumor cells can locate in vessels and proliferate at distance from the primitive site, thus forming secondary tumors. Generally, metastases are detected by imaging or serology at a very advanced stage of cancer disease. The aim of this study was to detect isolated or disseminated cells (CTCs) of CEDVADS in blood stream by three different approaches : 1) the study of molecular markers for the diagnosis of node involvement of epidermoid carcinomas of the upper aerodigestive tract using quantitative PCR in real time and OSNA. 2) Screening of tumoral cells disseminated in Redon drains after cervical curettage 3) Detection of circulating tumor cells after surgery for epidermoid carcinomas of stage III and IV VADS. This protocol will allow to validate the detection of CTCs in clinic setting and to develop prospective studies for the diagnosis and prognosis of CTCs of CEVADS

Long Term Evolution (LTE) developed by Third Generation Partnership Project (3GPP) is expected to be the standard of the Fourth-Generation (4G) of wireless communication system. LTE supports Frequency Division Duplex (FDD) and Time Division Duplex (TDD), and both of them are based on Orthogonal Frequency Division Multiplexing (OFDM) system in downlink. OFDM systems are sensitive to timing and frequency offset. Therefore, synchronization plays an important role in OFDM systems. In this thesis, we study synchronization problems of a LTE FDD baseband receiver. Particularly, we develop a complete procedure to deal with the synchronization problems. The basic design concept and procedure are as follows: The receiver estimates and compensates the timing and frequency offset by using the repetition property of the cyclic prefix. In the meanwhile, the receiver also detects cyclic prefix mode (or the length of the cyclic prefix). After the frequency offset has been compensated, the receiver then processes cell search. To this end, we multiply each subcarrier by the synchronization sequence provided by LTE specification and transform them into time domain. We then estimate the channel energy in time domain to detect the Cell Identity (Cell ID). Using computer simulations, we verify that the designed receiver performs well.

This research delves into wireless communication systems, with a particular focus on initial access processes, channel modeling, and beamforming strategies. The study involves meticulous channel data collection across diverse urban, suburban, and rural terrains, each presenting unique propagation challenges. The research also simulates a typical communication network with four base stations, adjusting their configurations to suit the varied terrains. A central focus is the implementation of the cell search methodology, including the exploration of random beamforming at both system and cell levels. The findings indicate that the cell-level system configurations do not yield significant performance improvements over the baseline configuration. Furthermore, potential increased costs associated with this strategy are noted. However, it is essential to highlight that this project serves as a critical exploration of the potential benefits of random beamforming at the cell level within non-public network scenarios. While the improvements observed are minimal, the insights gained from this research are poised to guide future research endeavors and contribute to the elimination of uncertainties in the field of wireless communication. / Denna forskning fördjupar sig i trådlösa kommunikationssystem, med särskilt fokus på initiala åtkomstprocesser, kanalmodellering och strålformningsstrategier. Studien involverade noggrann kanaldatainsamling över olika urbana, förorts- och landsbygdsterränger, var och en med unika spridningsutmaningar. Forskningen simulerade också ett typiskt kommunikationsnätverk med fyra basstationer som justerade deras konfigurationer för att passa de varierande terrängerna. Ett centralt fokus var implementeringen av cellsökningsmetoden, inklusive utforskning av slumpmässig strålformning på både system- och cellnivå. Resultaten indikerade att systemkonfigurationerna på cellnivå inte gav signifikanta prestandaförbättringar jämfört med baslinjekonfigurationen. Dessutom noterades potentiella ökade kostnader förknippade med denna strategi. Det är dock viktigt att betona att detta projekt fungerade som en kritisk utforskning av de potentiella fördelarna med slumpmässig strålformning på cellnivå inom icke-offentliga nätverksscenarier. Även om de observerade förbättringarna var minimala, är insikterna från denna forskning redo att vägleda framtida forskningsinsatser och bidra till att eliminera osäkerheter inom området trådlös kommunikation.

In dieser Bachelorarbeit wird eine LTE Cell Search Procedure auf Basis von SDR entwickelt, um eine Synchronisation mit einem LTE-System in Zeit und Frequenz zu erreichen. Dabei werden mehrere Verarbeitungsblöcke implementiert, die zur LTE Cell Search Procedure gehören. Diese beinhalten die Erkennung des Integer Frequency Offsets (IFO), Primary Synchronisation Signals (PSS), Fractional Frequency Offset (FFO) und des Secondary Synchronisation Signals (SSS). Die Arbeit umfasst eine Literaturrecherche, die Implementierung der Verarbeitungsblöcke, die Simulation verschiedener Szenarien, statistische Analysen und die Anwendung auf ein gemessenes LTE-Signal. Sie liefert Antworten auf spezifische Forschungsfragen zur Effizienz, zum Einfluss des SNR und des CFO, sowie zur Eignung für reale LTE-Systeme. Darüber hinaus wird ein Ausblick auf mögliche Anwendungen im Kontext von 5G NR, WLAN und Erweiterungen gegeben.:Kurzfassung.................................... III Abbildungsverzeichnis .............................. VII Tabellenverzeichnis................................ VIII Codeverzeichnis.................................. IX Abkürzungsverzeichnis .............................. X Symbolverzeichnis ................................ XIV 1. Einleitung................................... 1 1.1. Forschungsfragen ............................ 1 1.2. Untersuchungsdesign .......................... 2 2. Grundlagen .................................. 3 2.1. Zadoff-Chu (ZC)-Sequenzen ...................... 3 2.2. Maximum Length (M)-Sequenzen................... 5 2.3. Orthogonal Frequency-Division Multiplexing (OFDM) ................ 7 2.4. Orthogonal Frequency-Division Multiplexing (OFDM): Kanal und Equalization............................... 10 2.5. Orthogonal Frequency-Division Multiplexing (OFDM): Carrier Frequency Offset (CFO).......................... 11 2.6. Carrier Frequency Offset (CFO)-Erkennung ................... 14 2.7. Short Time Fourier Transform (STFT) und Spektrogramm ......... 16 2.8. Software Defined Radio (SDR) .................... 17 2.9. 3rd Generation Partnership Project (3GPP)-Long Term Evolution (LTE).................................. 18 3. Praktische Untersuchung ........................... 23 3.1. Simulationsumgebung ......................... 27 3.2. Software Defined Radio (SDR)-basierte Long Term Evolution (LTE)- Messung................................. 29 3.3. Integer Carrier Frequency Offset (IFO)-Erkennung ............ 30 3.4. Primary Synchronization Signal (PSS)-Erkennung .............. 38 3.5. Fractional Carrier Frequency Offset (FFO)-Erkennung ........ 44 3.6. Secondary Synchronization Signal (SSS)-Erkennung ............ 49 3.7. Simulation der gesamten Implementierung .................... 57 4. Zusammenfassung und Ausblick ....................... 62 Literaturverzeichnis................................ 65

Narrowband Internet-of-Things (NB-IoT) is a new wireless technology designed to support cellular networks with wide coverage for a massive number of very cheap low power user devices. Studies have been initiated for deployment of NB-IoT in unlicensed frequency bands, some of which demand the use of a frequency-hopping scheme with a short channel dwell time. In order for a device to connect to a cell, it must synchronize well within the dwell time in order to decode the frequency-hopping pattern. Due to the significant path loss, the narrow bandwidth and the device characteristics, decreasing the synchronization time is a challenge. This thesis studies different methods to decrease the synchronization time for NB-IoT without increasing the demands on the user device. The study shows how artificial fast fading can be combined with denser reference signalling in order to achieve improvements to the cell acquisition and synchronization procedure sufficient for enabling unlicensed operation of NB-IoT. / Narrowband Internet-of-Things (NB-IoT) är en ny trådlös teknik som är designad för att hantera mobilnät med vidsträckt täckning för ett massivt antal mycket billiga och strömsnåla användarenheter. Studier har inletts för att operera NB-IoT i olicensierade frekvensband, varav några kräver att frekvenshoppande spridningsspektrum, med kort uppehållstid per kanal, används. För att en användarenhet ska kunna ansluta till en basstation måste den slutföra synkronisingsfasen inom uppehållstiden, så att basstationens hoppmönster kan avkodas. På grund utav den stora signalförsvagningen, den smala bandbredden och användarenhetens egenskaper är det en stor utmaning att förkorta synkroniseringstiden. Detta examensarbete studerar olika metoder för att förkorta synkroniseringstiden i NB-IoT utan att öka kraven på användarenheten. Arbetet visar att artificiell snabb-fädning kan kombineras med tätare referenssignalering för att uppnå förbättringar i synkroniseringsprocessen som är tillräckliga för att möjliggöra operation av NB-IoT i olicensierade frekvensband.

Nowadays in the fifth generation (5G) communication systems, millimeter wave (mmWave) has aroused interest to not only industrial use but also network operators due to the massive amount of bandwidth available at mmWave frequencies. Initial access in cellular systems is an essential procedure in which new mobile user equipment (UE) establishes a connection with a base station (BS). However, mmWave relies on highly directional beamforming (BF) to overcome its severe path loss, while the initial access requires a wide beam to obtain sufficient information for beamforming. So the challenge is to handle the balance between highly directional mmWave and fast and reliable initial access. The high path loss of millimetre wave transmission dictates that multiple BSs may be closer and interfere more with each other. We focus our study on two BS parameters under the random search method. In our study, the beamwidth can be different for each BS, but a uniform number of slot limits needs to be chosen for all BSs. Our objective is to obtain the best parameters for each BS in a reasonable period of time. We build a systemlevel simulation in MATLAB and explored a variety of methods to select the best parameters, including reinforcement learning, supervised learning, and genetic algorithms. It is identified that the main challenge of applying reinforcement learning and supervised learning is the exponentially growing variety of BS parameters. A genetic algorithm is able to derive approximate best values in complex relational species. Therefore the genetic algorithm is considered to be able to be applied in scenarios with a high number of BSs. The result shows that reinforcement learning has great performance in a few BS cases, and the genetic algorithm is able to provide a large improvement over most of the BS methods with the same parameters. / I den femte generationens kommunikationssystem har millimetervågor väckt intresse, inte bara inom industrin utan även hos nätverksoperatörer, på grund av den enorma bandbredd som finns tillgänglig vid mmWave-frekvenser. Initial access i cellulära system är ett viktigt förfarande där ny mobil användarutrustning upprättar en anslutning till en basstation. mmWave är dock beroende av starkt riktad strålformning för att övervinna den allvarliga vägförlusten, medan den inledande åtkomsten kräver en bred stråle för att få tillräcklig information för strålformning. Utmaningen består alltså i att hantera balansen mellan mycket riktgivande mmWave och snabb och tillförlitlig initial access. Den höga vägförlusten för millimetervågsöverföring innebär att flera stationära basstationer kan vara närmare varandra och störa varandra mer. Vi fokuserar vår studie på två parametrar för BS med hjälp av metoden för slumpmässig sökning. I vår studie kan strålbredden vara olika för varje BS, men ett enhetligt antal slotgränser måste väljas för alla BS. Vårt mål är att få fram debästa parametrarna för varje BS på en rimlig tidsperiod. Vi bygger upp en simulering på systemnivå i MATLAB och utforskade en rad olika metoder för att välja de bästa parametrarna, bland annat förstärkningsinlärning, övervakad inlärning och genetiska algoritmer. Det konstateras att de största utmaningarna vid tillämpning av förstärkningsinlärning och övervakad inlärning är det exponentiellt växande utbudet av parametrar för BS. Genetisk algoritm kan härleda ungefärliga bästa värden i komplexa relationella arter. Därför anses den genetiska algoritmen kunna tillämpas i scenarier med ett stort antal BSs. Resultatet visar att förstärkningsinlärning har stor prestanda i ett fåtal BS-fall och att genetisk algoritm kan ge en stor förbättring jämfört med de flesta BS-metoder med samma parametrar.