JPS5496945A - Automatic equalizer - Google Patents

Abstract

PURPOSE:To obtain an automatic equalizer which has the normal operation in the section of a long-distance cable by providing (N+1)-units of filters which emphasize the high-band frequency component in proportion to n-power of the frequency plus the 1st and 2nd multipliers to multiply the coefficient by the output of the filter. CONSTITUTION:With supply of the signal which received the amplitude distortion from terminal 1, the signal is supplied to filters 21-2N whose frquency characteristics are proportional to f, f<2> ... fN respectively. Coefficients a1-an are memorized in memory circuits 50-5N, and a multiplication is given between these coefficients and the output of the filters via 1st multipliers 30-3n to obtain the signal by which a fixed coefficient is multiplied. Coefficient (b) memorized in memory circuit 11 is multiplied by the output of the 1st multiplier via 2nd multipliers 40-4N. The difference between the ideal waveform from terminal 15 and the equalization output given from terminal 14 is obtained through difference circuit 10, and the error signal of the output is multiplied by the output of the 2nd mutiplier through multipliers 70-7N. The difference between the coefficients given from output circuit 5 of multiplier 7 is memorized in circuit 5 as the new coefficient (a). With repetition of these processes, the signal the input signal of which is equalized is delivered from terminal 14 via adder 9.