Abstract:A twice-correlate code-acquisition circuit and a rapid acquisition algorithm are proposed according to the characteristics of multi-code and time-limited acquisition for Phys-ical Random Access Channel (PRACH) preamble part in WCDMA reverse link. Compared with the conventional matched-filter and parallel acquisition methods, this scheme has lower complexity with fast series correlate calculation for multiple codes in the fcwice-correlate cir-cuit. The proposed acquisition algorithm uses the information of multiple paths to achieve higher detection probability in multi-path fading environments than that in single patli fad-ing channel. Performance analysis with theory expressions and numerical results is provided.