Patent ID: 8238817
Filing Date: 2012-08-07
Classification: H04B

Abstract:
1. A method for reducing echo noise in satellite communications, the method comprising the steps of: transmitting a transmit signal from a hub to multiple remote stations, where the transmit signal contains at least one carrier; storing a replica of the transmit signal; distorting the replica according to satellite transponder nonlinearities; determining a scaled, delayed and distorted replica of the transmit signal to provide a compensated distorted replica of the transmit signal; using the compensated distorted replica to compensate for satellite transponder nonlinearities and reduce echo noise from a received aggregate signal received by the hub from the multiple remote stations; wherein the determining step further comprises applying a block conversion to the transmit signal to form the distorted replica occupying a predetermined frequency range; wherein the determining step further comprises correcting means for correcting for distortion in the aggregate signal by determining normalized gain and phase error in the aggregate signal to compute the replica of an echo noise signal; and wherein the determining step further comprises second means for determining a delay in the aggregate signal by computing a least mean square fractional sample of the aggregate signal and tracking changes therein to determine the delay.