| 摘要 |
Data is extracted from a demodulated signal by sampling the signal in successive phases over successive cycles; determining whether each sample value corresponds to a zero cross-over point; recording the occurrence of each cross-over point against the phase in which it occurs in a cycle so as to build up a histogram of cross-over points; selecting a sampling point P from the histogram as the phase of a maximum number of cross-over points; recording the occurrence of successive sample values over successive cycles of the signal in an array of samples values against the phase of a cycle so as to build up the data equivalent to an eye-pattern; determining selection thresholds T both sides of the zero value as minima in the distribution of the recorded occurrences of sample values at the sampling point; and determining whether the sample value at the sampling point P in successive cycles has a value within or outside the selection thresholds T and allocating a corresponding decoded value to that cycle of the signal. |
