Patent ID: 8224268

Claim:
A communication system comprising: a tone generator configured to generate a first tone, a second tone, and a third tone, the third tone having a frequency that is a harmonic product of at least one of the frequencies of the first tone and the second tone, the first tone, the second tone, and the third tone conveyed into an amplifier of a transmitter from the tone generator; a transmitter configured to transmit a test signal comprising the first, second, and third tones, the transmitter comprising a predistortion system; a receiver that is communicatively coupled to the transmitter and is configured to receive and process a received test signal corresponding to the test signal; and a controller configured to generate a set of correction coefficients based on a measured interaction of the third tone with a non-linear signal component in the received test signal, the set of correction coefficients being provided to program the predistortion system of the amplifier for substantially linearizing communication signals transmitted via the transmitter; wherein the tone generator generates the third tone, the third tone conveyed into the amplifier, at a frequency that is selected as the harmonic product of at least one of the frequencies of the first and second tones, and wherein the controller is configured to generate a set of correction coefficients for a corresponding harmonic of the communications signals transmitted via the transmitter to prelinearize the amplifier; wherein the tone generator further comprises a phase adjuster that is configured to rotate a phase of the third tone relative to the first and second tones through a range of phases, wherein the controller controls the phase adjuster to rotate the phase of the third tone; and wherein the measured interaction of the third tone with the non-linear signal component varies as a function of a phase relationship of the third tone relative to the first and second tones.