A Blind Beamforming Algorithm for Antenna Arrays in Cellular CDMA Systems

This paper presents a new blind beamforming algorithm for antenna arrays of direct-sequence code-division multiple-access (DSSS-CDMA) systems. The aim of such an algorithm is to enhance the signal-to-interference-plus-noise ratio (SINR) of the received signal by using only the signals available at the CDMA correlators. In this context, a novel formulation for the optimization problem usually considered for developing this type of beamforming algorithm is first introduced. Then, the gradient method is used to solve such optimization problem in real time, resulting in the proposed beamforming algorithm. As compared with the other algorithms available in the open literature, the proposed one leads to a better tradeoff between the amplification of the signal of interest and attenuation of the interferences, which in turn improves the SINR of the received signal. Numerical simulation results are presented aiming to demonstrate the effectiveness of the proposed algorithm.