1 research outputs found
Use of Multiple Antennas for DS/CDMA Code Acquisition
Manuscript received August 13, 2001; revised February 19, 2002; accepted
March 6, 2002. The editor coordinating the review of this paper and approving
it for publication is R. A. Valenzuela.A generalized acquisition scheme is proposed for direct
sequence code-division multiple-access systems with multiple
antennas. The proposed scheme employs grouping of multiple antennas
as a means of a tradeoff between two important factors determining
the mean acquisition time, combining gain and search
time. The performance of the proposed acquisition scheme is analyzed
in frequency-selective Rayleigh-fading channels with consideration
of spatial correlations. Numerical results show that the use
of the largest number of antenna groups is preferable to reducing
the mean acquisition time at low signal-to-interference ratio (SIR)
values. At high SIR values, on the contrary, the mean acquisition
time is found to increase in proportion to the number of antenna
groups. In a typical environment, the presence of spatial correlation
is shown to increase or decrease the mean acquisition time
within 50% compared with the uncorrelated fading case.This work was supported in part by the
Brain Korea 21 Project