| 摘要 |
PURPOSE:To make constitution simple and miniature, by detecting an error rate by passing four signal waves, branched from the output of a phase detector performing synchronous detection from a four-phase phase-modulated wave and regenerated carrier, through an amplitude discriminator to obtain a pulse wave. CONSTITUTION:Phase-modulated signals are applied to phase detectors 11 and 12 and detected synchronously, outputs equivalent to phase differences are waveform- shaped by LPFs 14 and 15, and data signals discriminatively regenerated by level discriminators 16 and 17 are sent out. Outputs 1 and 2, branched from outputs of those detectors 11 and 12, have cross phase relation and are passed through amplifiers 18 and 19 to obtain positive and negative outputs. By being supplied with those four signals waves, the phase shifter composed of potentiometers 201 204 generated corresponding outputs to amplitude discriminators 211 214, where they are converted into pulses, and their outputs are multiplied, two by two, in a tournament way by OR-ELSE circuits 221 223, so that error-rate detector 24 will detect an error rate from the variation in output. Consequently, the constitution can be made simple and miniature. |
