PAPR Reduction of OFDM Systems Using Heuristic optimization algorithm-Based Tone Injection Schemes

High peak-to-average power ratio (PAPR) of the transmitted signal is one of the limitations to employing orthogonal frequency division multiplexing (OFDM) system. This paper considers the use of the tone injection (TI) scheme to reduce the PAPR of an OFDM signal. However, optimal TI (OTI) requires an exhaustive search over all combinations of possible constellations, which is an NP-hard problem. To reduce the computation complexity while still obtaining the desirable PAPR reduction, we introduce the harmony search algorithm (HS), an effective algorithm that solves various combinatorial optimization problems, to search the over all combinations of possible permutations of the expanded constellation with low complexity. In this work we present a novel convex optimization approach to numerically determine the TI solution based on harmony search algorithm (HSTI) for PAPR reduction. As compared to the conventional TI scheme, the proposed one achieves almost the same PAPR reduction performance with much lower computational complexity. Computer simulation results show that the proposed HSTI algorithm obtains the keeping good PAPR reduction with low computational complexity and processing time. . Keywords—Orthogonal frequency division multiplexing, Harmony search algorithm, Peak-to-average power ratio reduction, Tone injection