Performance analysis of coherent reverse link in W-CDMA system employing adaptive array antennas

Adaptive array antennas have emerged as a promising technique to enhance the capacity of a mobile communication network by offering a unique spatial channel to each user. Also, they have the advantage of ISI (intersymbol interference) suppression by diminishing the multipath fading effect that occurs in wideband data transmission through wireless channels. In this paper, the performance of coherent reverse link W-CDMA systems using adaptive array antennas is analyzed by a statistically rigorous spatio-temporal channel model and chip-level simulator. In order to evaluate the performance of the adaptive array antenna systems accurately, the channel model used in the simulation should satisfy the spatial correlation characteristics which mainly depend on the distance between the array elements and the temporal correlation characteristics due to the mobility of the vehicle. Thus, the spatially and temporally correlated vector channel model is investigated theoretically and a channel simulator satisfying above properties is implemented. Also a chip-level simulator integrating the W-CDMA modem with a 2D-RAKE receiver is implemented. This chip-level simulator eliminates the approximation errors of the analytic approach and enables one to evaluate the performance including the effects of the forward error correction code, interleaving and channel vector estimation errors.