Patent ID: 8462616
Filing Date: 2013-06-11
Classification: H04B,H04L

Abstract:
1. An apparatus for estimating a frequency shift and a time shift in a CDMA signal based on a CDMA code associated with a CDMA signal, comprising: a modulation removal stage for removing a data and CDMA code modulation from the CDMA signal to acquire a modified CDMA signal; a frequency domain transformer for transforming the modified CDMA signal to the frequency domain to acquire a modified CDMA spectrum; a frequency shift detector for detecting a group of candidate frequency shifts based on the modified CDMA spectrum; a processing stage for processing the CDMA signal and a candidate frequency shift to acquire the time shift, when a combination of the CDMA signal, the CDMA code and the candidate frequency shift fulfills an optimization criterion and for selecting the candidate frequency shift as the frequency shift; and a controller for controlling the processing stage such that candidate frequency shifts from the group of candidate frequency shifts are processed and the time shift is detected.