Patent ID: 7826417
Filing Date: 2010-11-02
Classification: H04W

Abstract:
1. A method for controlling transmit power of a preamble sequence by a Subscriber Station (SS) in an Orthogonal Frequency Division Multiple Access (OFDMA) communication system, the OFDMA communication system adapted to transmit an Adaptive Antenna System (AAS) preamble sequence and a data symbol, the method comprising: determining a transmit power used for transmitting the data symbol; and determining a transmit power used for transmitting the AAS preamble sequence to be identical to the transmit power used for transmitting the data symbol; wherein the transmit power used for transmitting the data symbol is determined by at least one of propagation path loss, Carrier-to-Interference and Noise Ratios (CINRs) of the SS, and a reception error probability of received data symbols according to a mobility index of the SS, and wherein the mobility index is a value representing mobility of the SS, which is computed by measuring a reception CINR of downlink preamble sequences or uplink pilot signals and considering a time change of the measured reception CINR; and wherein, when a power control mode of the SS is an open loop power control mode, the transmit power used for transmitting the data symbol is determined by using both an estimated value for uplink propagation path loss and BS reception interference and noise reported by a BS.