V.A. Malishev, N.A. Mihailov

The First method duplex relationship uses the algorithm Widrow and is redused to artificial calculation of the estimation echo-signal in special adaptive filter or echo-compensator is realized on signal of the mistake with leaving the subtractor. The Other method to organizations duplex relationship uses the characteristic to invariance any linear echo-tract. Under invariance is understood conservation some characteristic sent signal and echo-signal on nearby block of the processing. In invariant echo-compensator manage-ment is produced by signal of the issue. The principle distinguish such echo-compensator from classical echo-compensator management is produced by signal of the issue. This principle distinguish such echo-compensator from classical echo-compensator, working at base of the algorithm Widrow. Algorithm of the operation invariant echo-compensator of the second order and his(its) structure is brought In article. Emphases is spared questions to stability of the work. They Are Shown way of the provision to stability. The first of them expect use special quadrupole. The second way of the provision to stability have brought about syntheses of the invariant asymmetric structure. The analytical expression is Brought on calculation own noise synthesized structure. It Is Made comparison of the technical features synthesized echo-compensator and echo-compensator, working at base of the algorithm Widrow. It Is Shown that designed invariant echo-compensator in size own noise greatly exceeds the classical echo-compensator. The Results of the study can be used in equipment xDSL and allow to enlarge the send rate on subscription network of the general use.