In order to solve the signal attenuation through channel at high data rate, a 1.5 GHz adaptive equalizer using error feedback at Rx(Receiver) is introduced. An equalizer based on discrete signal process is applied to reduce convergence time. Firstly, PRBS used as the training data will be transported to the equalizer filter for high frequency compensation. Then it is sampled and sliced by the S/H circuit and slicer to obtain steep rising and falling characteristics. Finally, it is sent to a comparator which is different with conventional comparator. There is an internal register in proposed comparator to store input signal. Error between input and desired value will be fed back through the closed loop to increase equalizer boosting gain. After several times iteration, useable gains are acquired and the median is selected as the optimal gain. If no suitable gain is found, Tx(Transmitter) will increase pre-emphasis setting and adaptive iteration progress at Rx repeats. Finally, the setting gain will be sent to inform Tx. The compensation range is from 1 to 16 dB. An experiment at 165.1 cm(65 in) 8 K module using CSPI protocol is carried out, where the validity of the proposed design is verified by feedback setting at Tx. The requirement that CSPI protocol data could be received and recovered without distortion by Rx at high data rate is met.