A Convex Optimization Algorithm for Reducing the Ber and Cubic Metric in OFDM Systems
ZHANG Xiang-yin;ZHU Xiao-dong;TANG You-xi;National Key Laboratory of Science and Technology on Communications,University of Electronic Science and Technology of China;
Since cubic metric(CM) can more accurately predict the power de-rating of power amplifier(PA), it is recognized as a better metric to characterize the envelope fluctuations of orthogonal frequency division multiplexing(OFDM) signals than peak-to-average power ratio(PAPR). To improve the PA efficiency, a common scheme is minimizing the CM value of signals. However, this aggravates the in-band distortion, resulting in bit error ratio(BER) degradation of systems. This paper formulates the problem as an in-band distortion optimization subject to CM constraint, and a customized interior-point algorithm is developed to solve the optimization problem. Simulation results show that the proposed algorithm provides better BER and CM-reduction performance than existing optimization schemes.