Partial transmit sequences for PAPR reduction of OFDM signals with stochastic optimization techniques

This paper considers the use of the partial transmit sequence (PTS) technique in reducing the peak-to-average power ratio (PAPR) of an orthogonal frequency division multiplexing (OFDM) signal. The conventional PTS technique is highly successful in PAPR reduction for OFDM signals, but the considerable computational complexity for the required search through a high-dimensional vector space is a potential problem for practical implementation. To reduce the search complexity while still improving the PAPR statistics, stochastic optimization techniques such as the simulated annealing (SA) algorithm, Cross-Entropy (CE) method, and particle swarm optimization (PSO) have recently been proposed to search for a phase factor that reduces both the PAPR statistics and the computational load. In this paper, a novel stochastic optimization approach, that is, the electromagnetism-like (EM) algorithm, is applied to reduce the PAPR of an OFDM signal. The computer simulation results show that compared with the various stochastic search techniques developed previously, the proposed EM method obtains the most desirable PAPR reduction with low computational complexity.