Abstract: Computer-implemented methods, computer software, and computer systems for adjusting receiver distortion caused by transmitter signals. A first signal is transmitted by a transmitter of the wireless terminal. A second signal is detected by a receiver of the wireless terminal. The second signal includes distortion caused by at least one of the first signal, a conjugate of the first signal, a harmonic of the first signal, or a conjugate of a harmonic of the first signal. At least one distortion coefficient is estimated in a digital domain based on the first signal and the second signal. Distortion of a third signal received by the receiver of the wireless terminal is adjusted based on the at least one distortion coefficient. Adjustment of distortion can be in the form of reduction, as well as elimination, of the distortion.

Abstract: Computer-implemented methods, computer software, and computer systems for adjusting receiver distortion caused by transmitter signals. A first signal is transmitted by a transmitter of the wireless terminal. A second signal is detected by a receiver of the wireless terminal. The second signal includes distortion caused by at least one of the first signal, a conjugate of the first signal, a harmonic of the first signal, or a conjugate of a harmonic of the first signal. At least one distortion coefficient is estimated in a digital domain based on the first signal and the second signal. Distortion of a third signal received by the receiver of the wireless terminal is adjusted based on the at least one distortion coefficient. Adjustment of distortion can be in the form of reduction, as well as elimination, of the distortion.

Abstract: Phase and gain of a transmit signal are measured at a transmitter by determining a first time delay having a first resolution at a measurement receiver between a reference signal from which the transmit signal is generated and a measured signal derived from the transmit signal by comparing amplitudes of the reference signal and the measured signal. A second time delay having a second resolution finer than the first resolution is determined at the measurement receiver between the reference signal and the measured signal based on the first time delay. The reference signal and the measured signal are time aligned at the measurement receiver based on the second time delay and the phase and gain of the transmit signal are estimated after the reference signal and the measured signal are time aligned.

Abstract: The present invention is a method for calibrating a phase distortion compensated polar modulated RF transmitter, which uses amplitude pre-distortion to compensate for phase distortion, called AMPM compensation. Some embodiments of the present invention may include a method for calibrating polar modulated RF transmitters that use amplitude pre-distortion to compensate for amplitude non-linearities, called AMAM compensation. The AMPM and AMAM compensations may enable the polar modulated RF transmitter to conform to RF output power tolerances, meet EVM specifications, and meet ORFS requirements. The pre-distortion calibration methods may be used to determine calibration constants by measuring phase distortion and amplitude non-linearities. During normal operation, the calibration constants may be used to provide the AMPM and AMAM compensations.

Abstract: Phase and gain of a transmit signal are measured at a transmitter by determining a first time delay having a first resolution at a measurement receiver between a reference signal from which the transmit signal is generated and a measured signal derived from the transmit signal by comparing amplitudes of the reference signal and the measured signal. A second time delay having a second resolution finer than the first resolution is determined at the measurement receiver between the reference signal and the measured signal based on the first time delay. The reference signal and the measured signal are time aligned at the measurement receiver based on the second time delay and the phase and gain of the transmit signal are estimated after the reference signal and the measured signal are time aligned.

Abstract: A system and method are provided for calibrating Amplitude Modulation to Phase Modulation (AM/PM) pre-distortion in a transmitter operating according to a polar modulation scheme. In general, phase modulation is disabled during transmission of an actual polar modulation signal. As a result, the transmitter provides a radio frequency (RF) output signal having an amplitude modulation component and ideally a constant phase. However, the AM/PM distortion of the transmitter creates a phase modulation component in the RF output signal. The phase component of the RF output signal, which is the AM/PM distortion of the transmitter, is measured by test equipment. The AM/PM pre-distortion applied by the transmitter is then calibrated based on the measured AM/PM distortion such that the AM/PM distortion of the transmitter is substantially reduced.