PN code acquisition for DS-CDMA systems employing smart antennas .II

Recently, a smart antenna, i.e., a blind adaptive antenna array, has attracted much attention to improve the capacity of a future code-division multiple-access wireless communications system. It has been demonstrated (Tanaka et al., 2000) that there is significant improvement in data demodulation through lab simulations and field experiments by employing a smart antenna of multiple elements. However, only one element is used for the pseudonoise (PN) code acquisition process, which is a coarse PN code synchronization prior to data demodulation. This paper proposes a simple and practical PN code acquisition scheme, which employs all elements in the smart antenna. Also, this paper uses an adaptive threshold for the PN code acquisition. Simulation results demonstrate that the proposed scheme can significantly improve the PN code acquisition performance, e.g., the PN code acquisition time will be half as long by employing five elements rather than the single element at a given bit-energy-to-interference power spectral density ratio.