| 摘要 |
A voice-protected, frequency-selective signal receiver for signals which consist of several simultaneously occurring individual frequencies, includes circuits for converting the received analog sum signal into a beat pulse pattern of positive and negative pulses of equal amplitude. The time interval between two pulses of identical operational signal and identical duration is determined, since this time interval corresponds to the duration of the sum signal and thus represents a clear criterion for the signal to be received. The signal receiver is utilized to advantage in multi-frequency code receivers in telecommunication systems, particularly telephone systems. |
