Universal automatic frequency control for multi-channel receivers
AssigneeSirius XM Radio Inc.
InventorsCarl Scarpa, Robert Joseph Topper
Life of this patent
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Abstract
Systems and methods for performing automatic frequency control are provided. Instead of relying on individual frequency tuners for each channel of a multi-channel receiver system, the present subject matter uses a single frequency tuner for receiving each channel of the multi-channel receiver system. A locked demodulator may be designated as a reference demodulator and frequency offset values associated with the reference demodulator may be applied to other demodulators of the multi-channel receiver. These frequency offset values may be used by individual demodulators of each channel for correcting corresponding frequency offsets.
Claims13
A data receiver, comprising:
- a tuner, wherein the tuner receives a plurality of modulated signals;
- and
- at least one processor, wherein the processor designates one of the plurality of modulated signals as a reference signal;
- wherein the at least one processor further detects a first demodulator that is locked onto a first signal of the plurality of modulated signals;
- wherein the at least one processor further determines that a frequency drift of the first demodulator satisfies a predetermined threshold drifts;
- and
- on a condition that the frequency drift satisfies the predetermined threshold shift, the at least one processor further calculates a frequency offset associated with the reference signal and the first demodulator adjusts the first modulated signal, based on the frequency offset, to generate a first demodulated signal.
A data receiver comprising:
- a tuner for receiving, over a satellite broadcast, a plurality of signals, wherein the plurality of signals are respectively demodulated by a plurality of demodulators;
- and
- at least one processor for designating one of the plurality of demodulators as a reference demodulator based on a predefined order;
- wherein the at least one processor further determines that a first demodulator of the plurality of demodulators is unable to lock to a corresponding first signal of the plurality of signals;
- and
- wherein the at least one processor further applies a reference frequency offset associated with the reference demodulator to the first demodulator, wherein the reference frequency offset is based on a frequency offset between a reference signal being received by the reference demodulator and an oscillator.
Dependencies are inferred from the claim text.