| 摘要 |
In order to obtain a phase-error signal from a convolution code signal for synchronisation purposes, the difference is formed between the minimum and maximum path metric. The magnitude and change with respect to time of this difference metric (DELTA-M) are evaluated in terms of magnitude and mathematical sign (SUBIII, SUBII). Values derived from the difference metric are subsequently added up or subtracted (ADD/SUB). If the change in the difference metric with respect to time is positive, a previously defined magnitude is subtracted from a current magnitude of the summation. If, in contrast, the change with respect to time is negative, the complement of a previously defined magnitude is added to the current magnitude of the summation. If the summation exceeds a threshold value (THRI), a phase-error signal (FAIL) is emitted (Figure 3). <IMAGE>
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