| 摘要 |
<p>A symbol timing recovery (STR) error detector (10) includes a complex multiplier (14) and a Gardner-type symbol timing error estimator (12) for operation with carrierless amplitude phase (CAP) signals. Quadrature Ir and Qr signals from the system are input to the complex multiplier, which also receives signals from a numerically controlled oscillator (16) operating at the CAP center frequency. The output of the complex multiplier is provided to the input of the Gardner STR error estimator. An added frequency shift allows the Gardner error estimator to function with CAP signals. The output from the error estimator is provided to a loop filter (110) the output of which is provided to an oscillator (112) which generates the symbol timing information (114) for a symbol sampling network (106).</p> |
