An initial code acquisition scheme for indoor packet DS/SS systems with macro/micro antenna diversity

In this paper, we study macro/micro diversity techniques for code acquisiti on of a direct-sequence spread-spectrum signal in an indoor packet communic ation system. In the system discussed, the base station has several radio p orts each with a cluster of antennas, and the terminal also has multiple an tennas. The performance in the uplink of this system is analyzed under Logn ormal shadowing and flat Rayleigh fading. The numerical results show great performance improvements by proposed diversity techniques. In addition, it is clarified that the mean acquisition time, which is often used as the mea sure of performance, is not suitable for packet radio systems as it underes timates the necessary preamble length for initial code acquisition.