Viasat, Inc.
Reducing signal distortion using I/Q imbalance or DC offset errors

Abstract:

To reduce signal distortion, a remote terminal receives a quadrature-modulated transmitter-check signal from a user terminal. The remote terminal measures an in-phase/quadrature (I/Q) imbalance error and/or a direct current (DC) offset error in the transmitter-check signal. The remote terminal then transmits to the user terminal transmitter-correction information derived from an I/Q imbalance error or a DC offset error. The transmitter-correction information is for counteracting the I/Q imbalance error or the DC offset error at the user terminal.