| 摘要 |
PURPOSE:To reduce the distortion of a reproduced waveform, to decrease the number of patterns of a code book, and to compress information to be transmitted by performing decoding reproduction processing as to all possible combinations of linear prediction coefficients, and reselecting the linear prediction coefficient which has the smallest waveform distortion and transmitting the information. CONSTITUTION:A linear predicting circuit 10 takes a linear predictive analysis based on a residual signal X after the pitch prediction of an input signal to extract a linear prediction coefficient Cj and a matching part 16 matches a noise sequence stored in the code book 15 with the residual signal E obtained by said linear predictive analysis to perform coding the information. Further, a linear prediction coefficient correcting means 1 performs the decoding reproduction processing of a residual signal E' selected by the matching part 16 as to all linear prediction coefficients which are possible at the time of coding transmission, and then process the residual signal X after the pitch prediction and respective S/Ns to reselect and transmit the linear prediction coefficient with the smallest waveform distortion to a decoding side. Consequently, the number of noise sequence patterns in the code book is reduced and code number information to be sent is reducible as well. |
