| 摘要 |
PURPOSE:To prevent that a value to be corrected is corrected by an excessive error quantity and a system diverges, by monitoring a mean value of amplitude of a receiving data, and limiting a correcting quantity of an automatic equalizer when said value exceeds a fixed value. CONSTITUTION:In case when an instantaneous amplitude increase is generated in a transmission line, a large value is generated in an output of an averaging circuit 7, is inputted to a deciding circuit 8, is compared with a value decided in advance, and in case of exceeding it, it is decided that an impulse noise is generated, and ''1'' is outputted to a timing circuit 9. An output of the timing circuit 9 becomes ''0'', and thereafter, it outputs ''0'' for a fixed period, and is returned to the original state ''1''. A selecting circuit 10 which receives the ''0'' output of the timing circuit 9 selects the reference decided in advance, instead of an excessive error quantity from a discriminator 6, outputs it to a correcting circuit 4, and it is prevented that a value of a register 2 is corrected abnormally by the excessive error quantity. |
