Coherent peak detection algorithms for utra first stage code acquisition

The first stage of UTRA code acquisition is the most crucial stage of the cell search process because it has to deal with the largest amount of uncertainty. We assume that the cell search starts when the mobile station is turned on with no prior information about the base station(s) that may be in the vicinity of the mobile station. The mobile station must acquire slot boundaries in order to obtain timing information of the detected base station. Therefore, this large amount of uncertainty gives longer mean acquisition time. In this thesis, we have devised four new peak detection algorithms for first stage code acquisition. We utilize the available base stations with few multipath signals along with the standard oversampling and pipelining utilization. We compare different coherent and non-coherent combining techniques and run simulations for different carrier frequency errors. We have developed simulation software using MATLAB, to simulate the performance of these algorithms. Our simulation results show that coherent combining for some of the new algorithms provide results close if not better than its non-coherent counterpart even at moderate carrier frequency errors especially at low signal to interference ratio