The present disclosure provides a method implemented in a wireless communication device for estimating a frequency offset between a carrier frequency of a received signal and a frequency of a local oscillator as well as the wireless communication device. The method comprises determining a plurality of phase change candidates for a phase change between a data symbol and a first reference symbol in the signal. The method further comprises generating a collection of constellation symbols from the data symbol and rotating the collection of constellation symbols by the plurality of phase change candidates. Then, one of the phase change candidates corresponding to one of the rotated collections of constellation symbols is selected in such a manner that said one of the rotated collections of constellation symbols matches a set of constellation points best. Next, the frequency offset is determined based on the selected phase change candidate.

The input samples transmitted by the base station are decimated and the decimated samples are correlated with the three reference PSS sequences to obtain the correlation results. The correlation results are differentially combined to obtain the hypotheses. The hypotheses are grouped into windows. The peaks across windows of multiple half frames are selected and obtained peaks are averaged over the multiple half frames to detect the half frame boundary window. Reference PSS versions are generated for ICFO estimation. The hypotheses are generated in the HFBW. The highest averaged hypothesis is selected to estimate ICFO. The ICFO error is corrected by adjusting a reference clock signal. The decimated samples are correlated and differentially combined around the HFB to determine a HFB and a FCFO from the peak value of the hypotheses. The received samples are correlated and differentially combined around the half frame boundary to further refine HFB and FCFO estimations.

Methods and apparatuses identifying a co-channel interference signal in communications systems are disclosed. An exemplary method comprises generating an interference signal by subtracting a reconstructed desired signal from an at least partially demodulated composite signal, and generating synchronization statistics of interference signal using different scrambling codes. The interference signal is identified as the signal associated with the scrambling code that was used to generate an interference signal having a desired synchronization statistic.