Implementation of the echo cancellation for DTMB repeater

Echo cancellation is one of the key technologies for digital repeater. Based on the Standard of China for DTMB (Digital Television Terrestrial Multimedia Broadcasting), a scheme of actualizing echo cancellation with adaptive filter is presented in this paper. Using matlab Simulink as the platform, we added PN sequence to digital TV signals, then, estimated the response of the coupling channel by using DLMS (Delayed Least Mean Square) algorithm. Finally, we generated a feedback signal to cancel echo with the estimation. In order to implement this scheme on hardware, we used retiming and folding technologies to save the hardware cost. The results of the computer simulation indicate a favorable performance in echo cancellation and low hardware cost.