摘要 |
A method and associated apparatus for preserving frequency spectrum in a linear modulation scheme, by adding a compensation signal to a modulated signal, the compensation signal having the same spectrum as the modulated signal. In the present invention, peaks above a pre-determined maximum threshold and/or minima below a pre-determined minimum threshold are searched. When a peak is found, the amount by which the signal peak exceeds the maximum threshold, as well as the signal phase at the peak is calculated. A compensation signal is generated with the same peak amplitude as the signal exceeds the maximum threshold, and with opposite phase. Then the shape of the compensation signal is chosen to be the same as the transmitter pulse of the modulated signal. Finally, the compensation signal is added to the modulated signal.
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