Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Space-Time Coded OFDM with Low PAPR Anand Venkataraman, Harish Reddy, and Tolga M. Duman | Hindawi Publishing Corporation EURASIP Journal on Applied Signal Processing Volume 2006 Article ID87125 Pages 1-9 DOI ASP 2006 87125 Space-Time Coded OFDM with Low PAPR Anand Venkataraman Harish Reddy and Tolga M. Duman Department of Electrical Engineering Arizona State University Tempe AZ 85287-5706 USA Received 11 January 2005 Revised 25 July 2005 Accepted 1 September 2005 Recommended for Publication by Alex Kot Recently the use of multiple-input multiple-output MIMO orthogonal frequency division multiplexing OFDM systems has been proposed for signaling over frequency-selective fading channels. Although various aspects of these systems have been considered in the literature the problem of the inherent high peak-to-average power ratio PAPR is not examined. In this paper we consider PAPR reduction for MIMO-OFDM systems and propose alternate low-complexity algorithms that can be used in conjunction with the trellis shaping method. We show that a PAPR reduction in the order of 4-5 dB can be achieved at the cost of a slight reduction in the spectral efficiency. Furthermore we compare the trellis shaping technique with other PAPR reduction techniques such as tone reservation and partial transmit sequences. Copyright 2006 Hindawi Publishing Corporation. All rights reserved. 1. INTRODUCTION Single-carrier modulation together with equalization and multicarrier modulation such as orthogonal frequency division multiplexing OFDM are used to overcome the challenges posed by dispersive channels. OFDM uses a number of subcarriers which are orthogonal to each other. Data is placed on each of the subcarriers and can be recovered at the receiver by exploiting the orthogonality among the subcarriers. Recently in addition to the single-input single-output OFDM systems space-time coded OFDM systems have been receiving significant attention. They were first proposed by Agrawal et al. in order to achieve data rates of Mbps over a bandwidth of 1 MHz 1 and it is shown that
