| 摘要 |
PURPOSE:To obtain frequency characteristics reducing inter-bit interference and displaying cosine square characteristics by means of a simple constitution by cutting off a half of the integer times a bit rate from an output of a converting means for converting cosine square frequency characteristics data previously stored in a storing means into an analog signal. CONSTITUTION:The cosine square frequency characteristics data are previously stored in a ROM 7 and the cosine square frequency characteristics data are supplied to a D/A converter 9 by specifying its address by outputs of delay elements 1-4, the input data of an input end 5 and the output of a counter 6. The D/A converter 9 converts the output of the ROM 7 into an analog signal and supplies the analog signal to a sample holder 10. The sample holder 10 samples the output of the D/A converter 9 on the basis of a reference clock supplied to an input end 8 and supplies the sampled signal to a filter 11. The filter 11 cuts off more than a frequency component corresponding to a half of the period of the reference clock supplied to the input terminal 8 and supplies the filtered component to an output terminal 12.
|
