Detection of direction and number of impinging signals in array antennas using cyclostationarity

Detection of the directions of arrival (DOA) and the number of impinging si gnals is an essential function in many array antenna beamforming techniques . A new approach is presented here for estimating the DOA and the number of desired signals in array antennas. The new algorithm exploits the cyclosta tionarity of the modulated signals, which are disturbed by unknown interfer ences and noises, to suppress undesired signals. In this approach, the outp uts of antenna sensors are applied to a linear prediction model and the cyc lic correlation is calculated to utilize the cyclostationarity of the desir ed signals. Also the error of estimation of the cyclic correlation function in the linear prediction model is evaluated and the DOA of the desired sig nals is correctly estimated. Results are compared with the results of conve ntional approaches, such as cyclic MU-SIC, in the presence of interference and at low signal-to-noise ratios. Numerical examples are presented to show the effectiveness of the proposed method. (C) 1999 Scripta Technica, Elect ron Comm Jpn Pt 1, 82(10): 29-39, 1999.