Key-Bits Interleaving Scheme for PAPR Reduction in OFDM Systems

Block interleaving scheme is known to improve PAPR performance of OFDM systems, but its effectiveness of PAPR performance optimization is limited due to the fact that there is a significant correlation among OFDM candidate sequences. In this paper, a key-bits interleaving scheme is proposed, which selectively interleaves only a minority of bits in the input binary sequence different from original block interleaving scheme. The main idea to construct key-bits interleaving scheme is to design the corresponding mapping constellations and select the first bit of each binary constellation point in the designed mapping constellations for interleaving, which is equivalent to employing 1 and -1 as phase weighting factors for weighting the mapped sequence in OFDM systems. Simulation results indicate that the proposed key-bits interleaving scheme can achieve better PAPR performance with the amount of interleaved data being reduced compared to original block interleaving.