Apparatus for error-correct decoding in a digital data communications system

摘要

In order to effectively error-correct decode a plurality of data frames transmitted over a noisy transmission channel, control data is applied to a maximum-likelihood decoder such as to change decoding parameters thereof. The control data is generated based on frame characteristic information obtained from at least one data frame which precedes a data frame currently decoded at the maximum-likelihood decoder. Thus, the error-correct decoding is implemented using estimated correlation between at least two consecutive data frames one of which is under error-correct decoding. Further, a cyclic code decoder is provided in a receiver for checking a transmission error in the output of the maximum-likelihood decoder. The cyclic code decoder issues a check result which is used to change the contents of the control data.