A robust adaptive algorithm for joint PN code acquisition and beamforming in DS-SS system employing antenna array

In this article, we proposed a robust adaptive algorithm for PN code acquisition and beamforming in direct sequence spread spectrum (DSSS) system with antenna arrays. Two adaptive filters are employed in the DSSS system, one is a spatial filter acting as a beamformer and the other is a temporal filter acting as a PN code-delay estimator. The cost function of LMS adaptive algorithm is given by constraining both the spatial filter weight and the temporal filter weight. A robust and fast adaptive algorithm with two different iterative step size is presented in the following. Computer simulations show that the proposed algorithm becomes more robust and faster, especially in DSSS system with a large spread spectrum gain.