| 摘要 |
PURPOSE: To obtain an audio signal band compression transmission system in which a noise component resulting from interference of system parameters is not generated in the case of synthesizing analog waveform. CONSTITUTION: A base signal outputted from a down sampling circuit 109 is given to a power detection circuit 113, where an absolute value is extracted and it is multiplied with a low frequency noise signal generated from a white noise generator 114 to obtain a base signal without no correlation to a linear prediction coefficient 8. obtained by a linear prediction analyzer 103. The base signal is fed to a linear prediction synthesizer 110, in which autoregression system arithmetic operation is applied to the base signal by using the linear prediction coefficient ai (i=1, 2, 3,...,N-1) obtained by a linear prediction analyzer 103 as a regression coefficient to obtain a narrow band time series signal. |
