Patent ID: 7136423
Filing Date: 2006-11-14
Classification: H04L

Abstract:
1. A method for reducing the peak-to-average ratio of a single-carrier or a multi-carrier modulated signal, the method comprising: storing an original discrete time signal; extending the original discrete time signal by adding a suffix to form an original discrete time extended signal; interpolating and upsampling the original discrete time extended signal at a fractional sampling rate to form an extended interpolated signal; generating sequences basis (Q) by partitioning available bins into a number of subsets, and taking N-dimensional inverse Fourier transforms of each subset at a rate of T; locally generating a PAR lowering sub-sequence (J) at T, in a time-domain, locally combining the PAR lowering sub-sequence and highest peak source at a scale of one extended symbol for multi-carrier modulation and at one or more of symbols for single-carrier modulation; searching for a signal peak that resulted from the combination of the PAR lowering sub-sequence and highest peak source; determining if the peak that resulted from the combination of the PAR lowering sub-sequence and highest peak source is an optimal peak that yields a low PAR; and combining the optimal peak that yields a low PAR and the original interpolated and upsampled discrete time signal that has been stored.