| 摘要 |
A system and method for synchronizing a Costas Loop for demodulating a received spread-spectrum signal having data and a first arbitrary phase angle, phi (t), using a phase detector, a phase unwrapping subsystem, an oscillator, a derotator and a decision device. A second arbitrary phase angle, theta (t), is generated from an in-phase component and a quadrature-phase component of the received spread-spectrum signal. The second arbitrary phase angle, theta (t), is proportional to the first arbitrary phase angle, phi (t). A value of theta proportional to theta (t) is then estimated. The estimated theta value is processed to obtain an estimate for the phi value, and a cosine and a sine of the estimated phi value are generated by the oscillator. The derotator derotates the in-phase-component and the quadrature-phase component of the received spread-spectrum signal with the cosine and the sine of the estimated theta value to generate a demodulated signal. The decision device evaluates the demodulated signal and outputs data.
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