| 摘要 |
A system and method are provided for detecting the frequency acquisition of a synthesized signal in a non-synchronous communications receiver. The method accepts a non-synchronous communication signal having an input data signaling frequency, and compares the input data signaling frequency to a synthesized signal frequency. In response to the comparing, a difference signal pulse is generated. More explicitly, the difference signal is generated at a rate responsive to the difference between the input data signaling frequency and the synthesized signal frequency. The method counts synthesized signal pulses occurring simultaneously with the difference signal pulse. If the counted synthesized signal pulses exceed a threshold (before the disappearance of the difference signal pulse), it is determined that the input data signaling frequency is about equal to the synthesized signal frequency, and a lock signal is generated. |
