Peak-to-average power ratio (PAPR) reduction using OFDM null subcarriers

Abstract

The proposed schemes reduce the peak-to-average power ratio (PAPR) of multi-carrier transmission, by exploiting null subcarriers, already mandated in most OFDM wireless standards. The dissertation has two distinct but related components, which are briefly summarized as below. (1) OFDM PAPR Reduction by Switching Null Subcarriers and Data-Subcarriers. This new approach requires no channel-side information (CSI), imposes no rate hit, is distortionless, can complement most other PAPR reduction methods (such as tone injection, tone reservation, active constellation extension, partial transmit sequences), and can be compatible with existing standards. This work has already been published in K. T. Wong, Bo Wang & J. C. Chen, "OFDM PAPR Reduction by Switching Null Subcarriers and Data-Subcarriers," Electronics Letters, vol. 47, no. 1, pp. 62-63, January 6, 2011. (2) OFDM PAPR Reduction by Shifting Null Subcarriers among Data-Subcarriers This new method has low computational complexity, is distortionless, has better symbol error rate (SER) performance, requires less channel-side information (CSI), can complement most other PAPR reduction methods (such as partial transmit sequences, selective mapping, tone injection, trellis shaping, active constellation extension), and also can be compatible with existing standards.