In multiple-access multicarrier systems, it is possible to serve multiple users at high data rates from a single base station. In this paper, we propose the multi-channel partial transmit sequences (MCPTS) method for multiple-access OFDM peak-to-average power ratio (PAR) reduction. By applying the PTS phase rotations to each access channel separately and assuming that the rotations can be detected by each user as a channel fading, MCPTS avoids two major disadvantages of standard PTS: i) the phase rotations can be detected without side information, and ii) the set of possible phase rotation values does not need to be finite. In addition, an iterative method of joint MCPTS and power allocation is proposed to minimize the average BER. The results show a significant BER improvement.
['Qijia Liu', 'Robert J. Baxley', 'Xiaoli Ma', 'G. Tong Zhou']
On the PTS method and BER-minimizing power allocation of the multi-channeL OFDM system