Patent ID: 8385442

Claim:
A method for reducing a peak-to-average power ratio (PAPR), the method being applied by using N sub-carriers, L sub-carriers of the N sub-carriers being reserved sub-carriers, L being less than N, the method comprising: receiving a data signal, the envelope power of the data signal having a constant power and a fluctuant power; generating L reserved sub-carrier symbols of the L sub-carriers located in the reserved sub-carriers; modifying the L reserved sub-carrier symbols according to the data signal, and generating a to-be-combined signal accordingly; and combining the to-be-combined signal into the data signal in frequency domain; wherein the data signal has N data symbols located in the N sub-carriers, the N data symbols correspond to an aperiodic auto-correlation function (AACF) vector, the L reserved sub-carrier symbols correspond to a reserved sub-carrier symbol vector, and in the step of modifying the L reserved sub-carrier symbols, the L reserved sub-carrier symbols are modified according to a gradient or any other algorithmic methods of the square of the absolute value of the AACF vector at the reserved sub-carrier symbol vector, or modified according to the absolute value for the AACF vector to the p th power, wherein p is larger than 0.