Patent ID: 7949059

Claim:
A method of processing an Orthogonal Frequency-Division Multiplex (OFDM) signal having a plurality of data carriers and a plurality of unused carriers, the method comprising: (a) transforming an original frequency-domain OFDM signal into a time domain signal; (b) simulating the effect of a non-linear amplifier on the time-domain signal to provide a potentially distorted time domain signal; (c) transforming the potentially distorted time domain signal into a potentially distorted frequency domain signal; (d) restoring at least some of any values of the data carriers in the potentially distorted frequency domain signal with corresponding values from said original frequency domain signal; (e) scaling at least some of the unused carriers in the at least partially restored frequency domain signal with a scaling factor; (f) transforming the scaled frequency domain signal into a temporary time domain signal; (g) analysing the temporary time domain signal for the presence of a peak or near zero amplitude value that would lead to distortion by said amplifier; and (h) responsive to said signal including such a peak or near zero value, repeating steps (e), (f) and (g) with an increased scaling factor.