POCS-based frame-theoretic approach for peak-to-average power ratio reduction in OFDM

Abstract

A new method for reducing peak-to-average power ratio (PAPR) in OFDM is proposed. The new method is based on using a projection-onto-convex-sets (POCS) algorithm in conjunction with the erasure pattern selection (EPS) method, which uses frame expansion for adding redundancy to the data. Part of the redundancy is removed by examining several patterns for erasing channels and selecting for transmission the pattern that produces the lowest PAPR. The residual redundancy in the data is exploited at the receiver to aid both the reconstruction of the erased data and correction of errors. The implementation is aided with the incorporation of a projection-onto-convex-sets (POCS) method in EPS in order to select and assign the best values to the unused subchannels and further reduce the PAPR. Two alternative methods of incorporating POCS are investigated. Complexity analysis and simulation results show that the POCS-based EPS method outperforms existing probabilistic methods while requiring lower overall complexity.