Performance analysis of spectral weighting techniques for smart antenna systems

In the present paper different weighting techniques for design of linear, equally spaced smart antenna systems (SAS) are examined. The main focus of the paper is to perform comparative analysis of weighting techniques which are used in harmonic analysis to reduce undesirable effects related to spectral leakage. The weighting technique is incorporated in a SAS that adapt the beam pattern to match the incoming data and optimize in a statistical sense. The major lobe is to be steered in the desired direction and the side lobes are to be suppressed so as to reduce the unwanted signals coming from undesired directions. The performance of antenna array as spatial filter depends on the two major aspects of array design, one geometrical configuration of array and second design of complex weightings of the data at each antenna output of the array. In the present article the techniques for choosing the weighting of each antenna array output to generate desired beam pattern are analyzed for optimum performance. The main concern is on various spectral weighting approaches equivalent to various windows or tapers used in the spectral analysis of time series.