Code and Time Synchronization of the Cell Search Design Influence on W-CDMA Systems

Abstract

The large-scale statistics of an improved cell search design (improved CSD) using cyclic codes is compared with the 3GPP cell search design using comma free codes (3GPP-comma free CSD) in terms of acquisition time for different probabilities of false alarm rates and to achieve faster synchronization at lower hardware complexity is addressed in this chapter. In the chapter we also proposes design improvements in stage 2 of the 3GPP-comma free CSD. The 3GPP-comma free CSD proposed in this chapter uses a Fast Hadamard Transformer (FHT) in stage 2 that achieves lower hardware complexity and faster decoding. Furthermore, masking functions are used in stage 3 of both the improved CSD and the 3GPP-comma free CSD to reduce the number of scrambling code generators required as described in previous work. This results in a reduction in the ROM size required to store the initial phases of the scrambling code generators in stage 3. The Improved CSD proposed in this chapter aims to achieve faster synchronization between the mobile station (MS) and the base station(BS) and thus improves system performance. Our results indicate that for a channel whose signal-to-noise ratio is degraded with additive white Gaussian noise (AWGN), the improved CSD achieves faster synchronization with the base station and has lower hardware utilization when compared with the 3GPP-comma free CSD scheme under the same design constraints.