Patent ID: 6798758
Filing Date: 2004-09-28
Classification: H04B

Abstract:
A method of acquiring initial diffusion code synchronization after receiving in a receiver CDMA-modulated signal, down-converting the CDMA signal into an analog signal, and sampling the analog signal to produce a complex digital signal, the method comprising:(a) performing N parallel complex correlations to obtain a correlation between components of the sampled complex digital signal and N parallel complex diffusion codes generated by the receiver; (b) accumulating, in parallel, components K continuously-generated parallel complex correlation results using, in parallel, the N parallel complex correlations; (c) obtaining, in parallel, energy values of the components of the accumulating step; and (d) determining a ratio of a maximum energy value to a mean energy value using the energy values of the components, comparing the ratio with a predetermined determination threshold, and, if the ratio is greater than or equal to the determination threshold, concluding diffusion code synchronization by determining that a code phase corresponding to the maximum energy value is a correct code phase, and otherwise, determining that the code phase corresponding to the maximum energy value is an incorrect code phase.