Patent ID: 8989250
Filing Date: 2015-03-24
Classification: H03F,H04L

Abstract:
1. A method for equalizing a digital pre-distorted signal for a linear complex response of an observation path of a digital pre-distorter, the method comprising: (a) generating a first multi-tone test transmit signal comprising multiple sinusoidal signal components separated in frequency by a first separation value; (b) generating first and second observed signals in the observation path based on observing the first multi-tone test transmit signal; (c) down-converting, using a first local oscillator (LO), the first observed signal into a first intermediate frequency signal and the second observed signal into a second intermediate frequency signal using a different local oscillator (LO) frequency for each of the first and second observed signals, a difference between the LO frequency for the first observed signal and the LO frequency for the second observed signal being equal to the first separation value; (d) calculating a first ratio between the first intermediate frequency signal and the second intermediate frequency signal; and (e) equalizing the digital pre-distorted signal for the linear complex response of the observation path using the first ratio.