| 摘要 |
PURPOSE:To attain wide use of the titled circuit to a PB receiver used overseas by using a stable adaptive filter for the identification of a voice and a PB signal so as to provide conventionality to the voice mulfunction preventing circuit. CONSTITUTION:The adaptive filter 11 and the decision circuit 12 discriminate whether an input signal is a PB signal or a voice and this information controls a function check logic 10. That is, a decision 15 of the decision circuit 12 supervises a difference signal being an output of the adaptive filter 11 and when the signal is a prescribed value or below, that is, when a forecast signal outputted from a forecast filter 14 is approximated to the input signal of the adaptive filter 11, a signal is outputted to a control circuit 16. The control circuit 16 compares the movement of the root of the forecast filter 14 with a root table of the voice stored in a table 17 and also a root table of the PB signal so as to discriminate whether the input signal is the voice or the PB signal and its information is outputted to the function check logic 10. Thus, the function check logic 10 prevents malfunction by the voice. The said table copes easily with various languages by changing or replacing the table. |
