Device and method of data recovery

A data recovery device, comprising:

• an equalizer, receiving an radio frequency (RF) signal and a compensation signal, tuning the RF signal according to the compensation signal, and outputting an equalized RF signal;
• a slicer, having an input terminal coupled to an output tenninal of the equalizer for receiving the equalized RF signal and slicing the equalized RF signal according to a slicing level to output an alternating current RF (AC_RF) signal, the AC_RF signal comprising a plurality of signal segments;
• a phase locked loop (PLL) circuit, having an input terminal coupled to an output terminal of the slicer for receiving the AC_RF signal and outputting a clock according to phases of the AC_RF signal;
• a detection circuit, coupled to the output terminal of the slicer and an output tenninal of the PLL circuit for receiving the AC_RF signal and the clock, calculating the time intervals of the AC_RF signal in the signal segments according to the clock, and detecting and outputting sampling heights of the signal segments;
• and
• a compensation circuit, coupled to the detection circuit and the equalizer, the compensation circuit selecting at least two of the sampling heights of the signal segments according to an output of the detection circuit, calculating a ratio of the at least two of the sampling heights, comparing the ratio with a corresponding reference to obtain a comparison result, and outputting the compensation signal to the equalizer according to the comparison result, the compensation circuit comprising:
• a gain calculation circuit coupled to the detection circuit, the gain calculation circuit categorizing the signal segments into m signal segment sets according to the time intervals of the signal segments, each of the signal segment sets comprising a plurality of signal segments having a same time interval, the gain calculation circuit averaging a plurality of sampling heights of each of the signal segment sets to generate an average amplitude, selecting at least two average amplitudes from m average amplitudes corresponding to the m signal segment sets, and calculating a ratio based on the at least two average amplitudes, wherein the ratio serves as a gain roll-off rate, and m is a positive integer;
• and
• a comparison circuit coupled to the gain calculation circuit, the comparison circuit receiving the ratio, comparing the ratio with the corresponding reference, and outputting the compensation signal accordingly.