Joint Suppression of PAPR and OOB Radiation for OFDM Systems

Orthogonal frequency division multiplexing (OFDM) systems have suffered from high peak to average power ratio (PAPR) and high out-of-band (OOB) power radiation issues, leading to degraded communication system performances. Taking advantage of the degrees of freedom (DOF) provided by time domain resources, i.e., cyclic prefix (CP), and frequency domain resources, i.e., guard subcarriers, we first cast the joint suppression of PAPR and OOB radiation as a non-convex optimization problem. Then we resort to a linearized alternative direction method of multipliers (LADMM) to deal with the problem. The proposed optimization problem and solution are completely different from the existing suppressing alignment and joint time-frequency suppressing alignment schemes, which address a convex relaxation optimization. Simulation results show that the LADMM algorithm outperforms the existing methods in reducing PAPR and OOB radiation, computational complexity, and BER performance.