Reducing the crest factor of a multicarrier signal

A method for reducing the crest factor of a multi-carrier signal, the method comprising:

• (a) evaluating an inverse Fourier transform of the multi-carrier signal, thereby generating a transformed multi-carrier signal;
• (b) defining a signal-to-be-corrected to be the transformed multi-carrier signal;
• (c) generating a simulated output signal;
• (d) estimating a signal maximum of the simulated output signal;
• (e) deriving a first correction variable on the basis of the estimate;
• (f) correcting the signal-to-be-corrected using at least the first correction variable, thereby generating a corrected output signal having a reduced crest factor;
• (g) defining the corrected output signal to be the signal-to-be-corrected;
• and
• (h) iteratively repeating steps (c) through (g) until the occurrence of a condition selected from the group consisting of causing the corrected output signal to have a crest factor below a predetermined threshold, and performing a predetermined number of iterations;
• the method further comprising reducing a bit width of the transformed multi-carrier signal.

A method for reducing the crest factor of a multi-carrier signal, the method comprising:

• (a) evaluating an inverse Fourier transform of the multi-carrier signal, thereby generating a transformed multi-carrier signal;
• (b) defining a signal-to-be-corrected to be the transformed multi-carrier signal;
• (c) generating a simulated output signal;
• (d) estimating a signal maximum of the simulated output signal;
• (e) deriving a first correction variable by identifying a particular sample point at which the estimate occurs;
• (f) correcting the signal-to-be-corrected using at least the first correction variable, thereby generating a corrected output signal having a reduced crest factor;
• (g) defining the corrected output signal to be the signal-to-be-corrected;
• and
• (h) iteratively repeating steps (c) through (g) until the occurrence of a condition selected from the group consisting of causing the corrected output signal to have a crest factor below a predetermined threshold, and performing a predetermined number of iterations.

A method for reducing the crest factor of a multi-carrier signal, the method comprising:

• (a) evaluating an inverse Fourier transform of the multi-carrier signal, thereby generating a transformed multi-carrier signal;
• (b) defining a signal-to-be-corrected to be the transformed multi-carrier signal;
• (c) generating a simulated output signal by simulating either a high-pass filter followed by a low-pass filter, or a fourth order IIR high pass filter and an FIR interpolation filter;
• (d) estimating a signal maximum of the simulated output signal;
• (e) deriving a first correction variable on the basis of the estimate;
• (f) correcting the signal-to-be-corrected using at least the first correction variable, thereby generating a corrected output signal having a reduced crest factor;
• (g) defining the corrected output signal to be the signal-to-be-corrected;
• and
• (h) iteratively repeating steps (c) through (g) until the occurrence of a condition selected from the group consisting of causing the corrected output signal to have a crest factor below a predetermined threshold, and performing a predetermined number of iterations.

A method for reducing the crest factor of a multi-carrier signal, the method comprising:

• (a) evaluating an inverse Fourier transform of the multi-carrier signal, thereby generating a transformed multi-carrier signal;
• (b) defining a signal-to-be-corrected to be the transformed multi-carrier signal;
• (c) generating a simulated output signal by stimulating an effect of a downstream filtering-and-interpolating system on the corrected output signal;
• (d) estimating a signal maximum of the simulated output signal;
• (e) deriving a first correction variable on the basis of the estimate;
• (f) correcting the signal-to-be-corrected using at least the first correction variable, thereby generating a corrected output signal having a reduced crest factor;
• (g) defining the corrected output signal to be the signal-to-be-corrected;
• and
• (h) iteratively repeating steps (c) through (g) until the occurrence of a condition selected from the group consisting of causing the corrected output signal to have a crest factor below a predetermined threshold, and performing a predetermined number of iterations.