Method and apparatus for implementing the training phase of adaptive decision feedback equalization

The invention relates to the system configuration; the transmission for QAM or a CAP modulating the digital communication circuit of signal based on self-adaptive channel equilibrium training stage method and device, the emitter or a receiver in the system configuration or the two comprises the band elimination filter formed solution, at least to form a stop-band on the signal spectrum. The method, using sparse tag set trained the joint equalizer, wherein sparse tag set and a symbol and instrument (S) is less than a symbol group symbol and number of the normal data transmission and a. The sparse mark units in a falling the stop-band the signal spectrum in marks of making interference floor with a relative to the power very low level, such length equalizer can be used to achieve a training a decision feedback balancer the correcting signal to the ratio high enough state recovery according to fix.