Patent ID: 11916704
Assignee: HUGHES NETWORK SYSTEMS, LLC
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A satellite demodulator comprising:
an analog-to-digital converter (ADC) block to receive analog forward downlink communications via a satellite channel and to output a corresponding stream of digital samples, the forward downlink communications manifesting satellite channel filter distortions associated with one or more channel filters in the satellite channel, such that the stream of digital samples is a channel-distorted sample stream, wherein the forward downlink communications includes a sequence of communication frames having at least one pre-equalizer frame that encodes a pre-equalizer frame code and a predetermined training sequence of digital symbols;
a demodulator path to generate a digital symbol stream from an undistorted sample stream; and
a pre-equalizer subsystem comprising:
a training buffer coupled with the ADC block to receive the channel-distorted sample stream;
an update trigger block to generate a trigger signal responsive to detecting decoding of the pre-equalizer frame code by the demodulator path, the trigger signal indicating receipt via the ADC block of the at least one pre-equalizer frame resulting in presence in the training buffer of a segment of the channel-distorted sample stream representing at least the predetermined training sequence of digital symbols;
a dynamic coefficient processor to:
receive at least a portion of the channel-distorted sample stream corresponding to the predetermined training sequence of digital symbols from the training buffer responsive to the trigger signal;
compute an updated set of compensation filter coefficients based on correlating the at least a portion of the channel-distorted sample stream to the predetermined training sequence; and
output the updated set of compensation filter coefficients; and
a pre-equalizer filter block coupled between the ADC block and the demodulator path to generate the undistorted sample stream by filtering the channel-distorted sample stream based on the set of compensation filter coefficients previously computed by the dynamic coefficient processor to at least partially compensate for the satellite channel filter distortions of the satellite channel.