Abstract: In a method for cancelling interference caused by a terrestrial transmitter at a satellite receiver in a hybrid satellite-terrestrial network, a satellite receiver generates an interference cancellation signal based on a reference terrestrial signal from the terrestrial transmitter and a received over-the-air (OTA) signal. The satellite receiver then cancels the interference caused by the terrestrial transmitter by combining the interference cancellation signal with the received OTA signal. The interference cancellation signal is a modified version of the reference terrestrial signal.

Abstract: In a method for cancelling interference caused by a terrestrial transmitter at a satellite receiver in a hybrid satellite-terrestrial network, a satellite receiver generates an interference cancellation signal based on a reference terrestrial signal from the terrestrial transmitter and a received over-the-air (OTA) signal. The satellite receiver then cancels the interference caused by the terrestrial transmitter by combining the interference cancellation signal with the received OTA signal. The interference cancellation signal is a modified version of the reference terrestrial signal.

Abstract: Methods and systems for recovering a DC component in a zero-IF radio receiver are disclosed that involve receiving a frequency modulated radio frequency broadcast signal, down-converting the frequency modulated radio frequency broadcast signal directly to an original baseband frequency signal, wherein the original baseband frequency signal includes an original DC component, filtering the original baseband signal to obtain a filtered baseband signal, wherein the original DC component is removed, analyzing modulus values of the filtered baseband signal to determine an estimated quantity for the original DC component, and adding the estimated quantity for the original DC component to the filtered baseband signal to compensate for removal of the original DC component such that a reconstructed baseband signal is obtained.

Abstract: Methods and systems for recovering a DC component in a zero-IF radio receiver are disclosed that involve receiving a frequency modulated radio frequency broadcast signal, down-converting the frequency modulated radio frequency broadcast signal directly to an original baseband frequency signal, wherein the original baseband frequency signal includes an original DC component, filtering the original baseband signal to obtain a filtered baseband signal, wherein the original DC component is removed, analyzing modulus values of the filtered baseband signal to determine an estimated quantity for the original DC component, and adding the estimated quantity for the original DC component to the filtered baseband signal to compensate for removal of the original DC component such that a reconstructed baseband signal is obtained.

Abstract: A phase tracker receives a signal component xn and forms a phase- and gain-corrected signal zn. In particular, the phase tracker performs a Hilbert transform of xn to produce a quadrature phase component yn to form the constellation defined by (xn, yn). Consequently, phase rotation and gain adjustment are combined into a linear transform of the constellation defined by (xn, yn). The linear transform zn=&agr;xn+&bgr;yn employs two coefficients &agr; and &bgr;. The coefficients &agr; and &bgr; of the linear transform are derived so as to provide an optimal solution according to minimum mean square error. Approximations to the coefficients &agr; and &bgr; of the linear transform may be iteratively determined with a stochastic gradient method. Advantages of employing the phase- and gain-corrected signal zn as an I-phase detection result of a demodulator include 1) the phase rotation and gain adjustment are combined into one operation, and 2) the a sine/cosine lookup table is not employed.