Lte Neighborhood Search Algorithm And The Implementation Architecture Research

The3rd Generation Partnership Project Long Term Evolution (3GPP LTE) is a nextgeneration standard for wireless communicaition. Cell search is an important physicallayer procedure by which a user equipment (UE) acqutires time and frequencysynchoronization with a cell and detects the physical layer cell ID of that cell.The cell search procedure is consisted of two basic parts: detecting the primarysynchronization signal (PSS) to obtain the physical layer identity ID and5ms frametiming and detecting the secondary synchronization signal (SSS) to obtain the physicallayer identity group ID and10ms frame timing. Also, the time/frequencysynchronization, cycle prefix (CP) mode detection and frequency/time divisionduplexing (FDD/TDD) system identity are obtained during this procedure.In the thesis, we focus on the cell search performance improvement as well asimplementation complexity reduction in the LTE FDD/TDD systems. First, the systemmodel and synchronization signals are introduced. Then, an algorithm for the PSSdetection utilizes threshold and partial cross-correlation is presented. The complexity ofthis algorithm is lower than that of the conventional method. Third, the CP detectionand carrier frequency offset (CFO) estimation are proposed. Finally, we propose thecoherent method and non-coherent method for the SSS detection.In addition, the link level simulation shows the performance of proposed algorithmin difference simulation environment parameters such as signal to noise ratio, carrierfrequency offset and Doppler shift. The simulation results demonstrate that the proposedalgorithms outperform the existing methods on both performance and averageacquisition time.Farthermore, we present the architecture of cell search algorithm implementation.A new low-complexity approximation is propsed to reduce the power and square rootconsumption. Finally, the fix point simulation result shows that both architecture designand fixed-point word length satisfy the system requirements.