| 摘要 |
PURPOSE:To enhance measuring efficiency, by calculating an error percentage characteristic by one measurement at each carrier wave-to-noise (C/N) point. CONSTITUTION:A transmitting side error percentage measuring device 1 is used as a mere pulse signal generator and a pulse signal la is applied to a PCM modulation device 2. Noise is added to the modulation output 2a of the device 2 by a noise applicator 3 and a modulation wave 3a having noise added thereto is applied to a PCM demodulation device 4. The number of errors or error rate of the output 4a of the device 4 is measured by a receiving side error percentage measuring device 5. Herein, a noise level to be applied is changed by the control signal 6a from a computer 6. In the computer 6, the value corresponding to the number of errors or error rate outputted from the measuring device 5 with respect to each C/N point is substituted for an approximate formula showing a constant straight line to calculate an error percentage characteristic. Therefore, labor is dispensed with and a measuring time is also shortened.
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