RF carrier synchronization and phase alignment methods and systems
AssigneePhasorLab, Inc.
InventorJoshua C. Park
Life of this patent
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Abstract
A method comprising generating a baseband information signal by mixing a received modulated carrier signal with a local oscillator (LO) signal having an LO frequency; obtaining baseband signal samples of the baseband information signal having a baseband signal magnitude and a baseband signal phase; determining a cumulative phase measurement associated with baseband signal samples having a baseband signal magnitude greater than a threshold; and, applying a correction signal to compensate for an LO frequency offset of the LO frequency based on the cumulative phase.
Claims18
A blind frequency synchronization method comprising:
- generating a baseband information signal by mixing a received modulated carrier signal with a local oscillator (LO) signal having an LO frequency;
- obtaining baseband signal samples of the baseband information signal having a baseband signal magnitude and a baseband signal phase;
- determining a cumulative phase measurement associated with baseband signal samples having a baseband signal magnitude greater than a threshold;
- and,
- applying a correction signal to compensate for an LO frequency offset of the LO frequency based on the cumulative phase,
- wherein the cumulative phase measurement is based on an instantaneous phase of a data signal within the received modulated carrier signal, and
- wherein determining a cumulative phase measurement comprises accumulating a plurality of differential phases between successive complex signal points, each of the successive complex signal points having magnitude greater than the threshold.
An apparatus comprising:
- a mixer and a local oscillator (LO) configured to generate a baseband information signal by mixing a received modulated carrier signal with an LO signal having an LO frequency;
- an analog to digital converter configured to generate baseband signal samples of the baseband information signal;
- a phase accumulator configured to receive the baseband signal samples and to determine a cumulative phase measurement associated with baseband signal samples having a baseband signal magnitude greater than a threshold;
- and,
- an LO correction module configured to apply a correction signal to compensate for an LO frequency offset of the LO frequency based on the cumulative phase,
- wherein the cumulative phase measurement is based on an instantaneous phase of a data signal within the received modulated carrier signal, and
- wherein the phase accumulator is further configured to accumulate a plurality of differential phases between successive complex signal points, each of the successive complex signal points having magnitude.
A method comprising:
- generating a baseband information signal by mixing a received modulated carrier signal with a local oscillator (LO) signal having an LO frequency, the modulated carrier signal being an in-phase signal and quadrature signal uncorrelated with each other and derived from different input data sets;
- obtaining baseband signal samples of the baseband information signal having an in-phase signal sample and a quadrature signal sample;
- determining an offset frequency rotation based on an estimated correlation between the in-phase signal samples and the quadrature signal samples;
- and,
- processing the baseband information signal using the offset frequency rotation,
- wherein the received modulated carrier signal is a quadrature-modulated signal with arbitrary orthogonal in-phase and quadrature signal components.
Dependencies are inferred from the claim text.