A Low Complexity Improved Tone Reservation Method Based on ADMM for OFDM Systems' PAPR Reduction

Although the Orthogonal Frequency Division Multiplexing (OFDM) system has many advantages, one of its major problems as a multi-carrier system is still the high peak-to-average-power ratio (PAPR). Among many PAPR reduction technologies, tone reservation (TR) technology is widely used due to its distortionless characteristic and low complexity. Its main idea is to use reserved subcarriers to generate peak cancellation signals (PCS) to reduce PAPR. Since solving the optimal PCS signal is a quadratically constrained quadratic program problem, this paper has proposed a suboptimal solution algorithm with low computational complexity called ADMM-TR. The main idea of the proposed algorithm is to combine the variable splitting alternate direction method of multiplier with the TR method, and the main operations in each iteration process are the multiplications of matrices and vectors. The conducted simulations and results show that the ADMM-TR algorithm can achieve an effective PAPR reduction performance with low complexity, and can converge after several iterations.