Patent ID: 7016431

Claim:
A transmitter for sending a signal over a wireless channel, comprising: a modulator for modulating the signal to produce a modulated signal that is distributed over a subcarrier; a predistorter for predistorting the modulated signal distributed over the subcarrier according to an amplifier transfer property in order to produce a predistorted signal; a mixer for converting the predistorted signal from a baseband frequency into an intermediate frequency in order to produce a converted signal; an amplifier for amplifying the converted signal in order to produce an amplified signal; an antenna for sending a first portion of the amplified signal; a mixer for mixing a second portion of the amplified signal down from the intermediate frequency to the baseband frequency in order to produce a mixed-down signal; a measurement module for comparing the mixed-down signal with the predistorted signal to determine the amplifier transfer property and for notifying the predistorter of the amplifier transfer property; a signal generator for generating a test signal; and an input element for inputting at preset times the test signal into one of the modulated signal, the predistorted signal, and the converted signal, wherein: the measurement module compares the test signal in the mixed-down signal with the test signal in the one of the modulated signal, the predistorted signal, and the converted signal to obtain the amplifier transfer property, and the signal generator generates the test signal having an envelope that is not dependent on time.