ADAPTION METHOD FOR COEFFICIENT OF MODEM EQUALIZER AND ADAPTION CIRCUIT

摘要

PURPOSE: To ascertain that a coefficient always takes out an appropriate code for a still value by storing the still value of the coefficient and taking out the coefficient while an instantaneous difference between the still value and a present value on the coefficient is calculated. ;CONSTITUTION: A memory cell 13 storing the coefficient Ci(t) and the next coefficient Ci(t+1), an adaptive module 16 outputting a signal C'i(t+1) from the coefficient Ci(t), an error signal E and a data value X are shown. An additional memory 30 is connected to the memory cell 13 in parallel at a write mode. Write mode connection is encoded by a switch 32. The content Ci(0) of the memory 30 is compared with a value C'i(t+1) in a comparator 34 but the comparator outputs plus or minus value as the function of the code of the difference. The value +1 or -1 is multiplied by the coefficient (k) approximated to '0'. Furthermore, the value ±k is added to the signal C'i(t+1) in an adder 38 and the value Ci(t+1) is outputted.;COPYRIGHT: (C)1993,JPO