| 摘要 |
<p>PURPOSE:To provide the digital modulation circuit suitable for the application to a data storage device such as a digital VTR or a transmission line system. CONSTITUTION:A converter 2 forms 1st and 2nd data strings by adding redundant bits being r-bits to each n-bit of an incoming digital signal and pre-coders 3, 4 are used to apply partial response code modulation to the data. Then detection means Eor1, 2 are provided respectively to the data strings to detect autocorrelation between prescribed bits of the incoming data. Which of the 1st and 2nd data strings are to be adopted is decided based on the result of detection to cause a peak or a dip for tracking. Thus, a signal for tracking with high accuracy is obtained and the integrated circuit is made small.</p> |
