Elimination of Side Peaks Using Cyclostationarity of Pilots for OFDM Signals

In this paper we investigate the reason on how the side peaks of ambiguity function are generated, and propose the solution to eliminate the side peaks, the occurrence of side-peak may mask the faint targets echoes at low signal-to-noise ratio (SNR), rendering target localization difficult. By developing cyclostationarity of pilots, we prove that the side peaks care caused by the periodicity of pilots in received OFDM signals, this is quite important in cognitive radio-aided passive correlation localization (CR-PCL). After sensing pilots structure, we get rid of these side peaks from the received targets echoes, therefore, the ambiguity function shows an ideal thumbtack-like ambiguity diagram and super delay-Doppler resolutions are obtained, simulations results verify that the proposed is robust to noise power uncertainty as performing the ambiguity function in a cognitive radio fashion.