Abstract: A fast and efficient blind beamforming algorithm for DS-CDMA systems is presented. It utilizes the Powell algorithm to determine conjugate searching directions, so as to maximize the combined output of correlators and to form a beam toward the DOA of the desired user by shifting the phase of each element. It simplifies the beamforming system and simulation results show that the proposed algorithm enhances the stability of beamforming and immensely reduces the computational load compared with available methods in literature. Furthermore, it leads to a better beampattern with fewer requirements for the convergence criteria. The number of iterations and multiplications required by this method is approximately 10％ that required by the available methods when only one path is received and this will be further reduced to 2％ that when two paths exist.

Key words: CDMA, smart antennas, array output power, beamforming, Powell algorithm