JPS56158538A - Automatic equalizer - Google Patents

Abstract

PURPOSE:To obtain an automatic equalizer without offset, by extracting the difference of input and output of a discriminator which obtains the estimated value of a transmission signal by taking the output of an equalizer as the input, and subtracting a value integrating it from the output of the equalizer. CONSTITUTION:An input signal 1 is given to a tapped delay line 2, and a value picked up via multipliers 3-5 to weight the output of each tap is added at an adder 6. The output of the adder 6 is outputted via a subtractor 11 and a discriminator 12. The transmission data estimated at the discriminator 12 and the input to the discriminator are given to a subtractor 13 to extract the error component, the value is given to multipliers 22-24, this is multiplied with the output of each tap of the delay line 2, the result is fed to integrators 28-30 via attenuators 25- 27 respectively, and the output of the integrators is given to the multipliers 3-5. Further, the output of the subtractor 13 is given to the subtractor 11 for the offset value integrating at 15 it via an attenuator 14. Thus, the multipliers 3-5 controls the weight of each tap of the delay line 2 automatically so that the output error is made smaller, and output is made from the adder 6 by the subtraction of the offset value.