Patent ID: 7457586
Filing Date: 2008-11-25
Classification: H03F,H04B,H04L

Abstract:
1. A method for calibrating Amplitude Modulation to Phase Modulation (AM/PM) predistortion of a transmitter of a mobile terminal comprising: transmitting a predetermined data pattern in a transmit burst to provide an output signal; changing a variable supply voltage controlling an output power of power amplifier circuitry of the transmitter from a first value to a second value during the transmit burst; measuring a phase shift caused by changing the variable supply voltage to the second value, wherein the phase shift is a phase shift between a phase of the output signal before changing the variable supply voltage to the second value and a phase of the output signal after changing the variable supply voltage to the second value; and selecting one of a plurality of predetermined sets of AM/PM predistortion coefficients as AM/PM predistortion coefficients defining the AM/PM predistortion of the transmitter of the mobile terminal based on the phase shift.