Patent ID: 7460614

Claim:
A digital baseband (DBB) transmitter comprising: a digital amplitude imbalance compensation module having real and imaginary signal paths, the digital amplitude imbalance compensation module being configured to adjust the amplitude characteristics of the real and imaginary signal paths; a controller in communication with the digital amplitude imbalance compensation module, the controller being configured to determine an amplitude compensation value used to adjust the amplitude characteristics of the imaginary signal path such that the real and imaginary signal paths substantially have the same amplitude; a digital chase imbalance compensation module in communication with the controller and having real and imaginary signal paths in communication with the real and imaginary signal paths of the digital amplitude imbalance compensation module, respectively, wherein the controller determines a phase compensation value used by the digital phase imbalance compensation module to adjust the phase difference between the real and imaginary signal paths to 90 degrees; a modem switchably connected to the real and imaginary signal paths of the digital amplitude imbalance compensation module, the modem having real and imaginary signal outputs; and first and second switches connected to the real and imaginary signal outputs of the modem, the real and imaginary signal paths of the digital amplitude imbalance compensation module and the controller, wherein the amplitude and phase compensation values are determined after the switches disconnect the modem from the real and imaginary signal paths of the digital amplitude imbalance compensation module and connect the controller to the real and imaginary signal paths of the digital amplitude imbalance compensation module.