| 摘要 |
In pulse signal transmission, the low-frequency signal components weakened or suppressed by a distorting transmission channel are transmitted in the form of a series of equi-spaced auxiliary pulses intercalated between successive groups of equal numbers of signal pulses. The distorted auxiliary pulses, which may have a zero, constant or quantized amplitude, are segregated at the receiver from the composite receiving signal and the segregated pulses converted by means of a low-pass filter into a subfrequency correcting signal which is applied to the composite signal in proper time phase and amplitude, to restore the original undistorted pulse signal. Where a continuous signal pulse series is transmitted having a constant pulse spacing distance throughout, special time compression and expansion means serve to compress successive groups of the pulses, to provide spacing intervals for the intercalation of the auxiliary pulses at the transmitter, on the one hand, and to restore the original continuous signal pulse series at the receiver, on the other hand.
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