Performance analysis of fast cell search algorithms for W-CDMA systems

• Main Author: Chen, Jian Lawrence
• Language: English
• Published: 2009
• Online Access: http://hdl.handle.net/2429/12068

A 3-stage fast cell search algorithm is adopted by the 3rd Generation Partnership Project (3GPP) committee as the method for establishing initial synchronization between a base station and a mobile station. The probability of detection analyses for stage 1 using the accumulation slot synchronization technique and stage 3 for Rayleigh fading channels have been previously studied. In this thesis, the probability of detection for stage 1 using the most frequent occurrence method is analyzed and the results are compared with the accumulation technique. It is found that the accumulation scheme outperforms the most frequent occurrence scheme. The stage 2 probability of detection is also analyzed. All three stages are then analyzed in Ricean fading. As expected, it is observed that the probability of detection for all three stages in Ricean fading is better than that under Rayleigh fading channel. A theoretical model for the mean cell search time is also introduced. The results show that the mean cell search time increases more rapidly for the independent fading channel than for the block fading channel as the channel condition degrades. The performance of the fast cell search algorithm was also studied using simulation. The simulation results were obtained based on SPW™ 3GPP model. Simulation results for a vehicular speed of 3 km/h were found to closely match the theoretical results assuming block fading. Results obtained assuming independent fading were found to be significantly different from simulation results for high vehicular speeds, e.g. 120 km/h. This is primarily due to the fact that even at this speed, the fading for consecutive slots are quite correlated.