LPC/RC to Autocorrelation
Convert linear prediction coefficients or reflection coefficients to autocorrelation coefficients
Library
Estimation / Linear Prediction
dsplp
Description
The LPC/RC to Autocorrelation block either converts linear prediction coefficients
(LPCs) to autocorrelation coefficients (ACs) or reflection coefficients (RCs) to
autocorrelation coefficients (ACs). Set the Type of conversion
parameter to LPC to autocorrelation or RC to
autocorrelation to select the domain from which you want to convert
your coefficients. The A port corresponds to LPC coefficients, and the K port
corresponds to the RC coefficients.
The block input can be an N-by-M matrix or an unoriented vector. Each column of the matrix is treated as a channel. When the input is an unoriented vector, the input is treated as one channel.
Use the Specify P parameter to set the value of the prediction
error power. You can set this parameter to 1 by selecting Assume
P=1. When you select Via input port, a P
port appears on the block. You can use this port to input the value of the actual,
non-unity prediction error power for each channel. The length of this vector must equal
the number of channels in the input.
The If first input value is not 1 parameter specifies the behavior of the block when the first coefficient of the LPC coefficient vector is not 1. The following options are available:
Replace it with 1— The block changes the first value of the coefficient vector to 1. The rest of the coefficient values are unchanged.Normalize— The block divides the entire vector of coefficients by the first coefficient so that the first coefficient of the LPC coefficient vector is 1.Normalize and Warn— The block divides the entire vector of coefficients by the first coefficient so that the first coefficient of the LPC coefficient vector is 1. The block displays a warning message telling you that your vector of coefficients has been normalized.Error— The block displays an error telling you that the first coefficient of the LPC coefficient vector is not 1.
Parameters
- Type of conversion
From the list select
LPC to autocorrelationorRC to autocorrelationto specify the domain from which you want to convert your coefficients.- Specify P
From the list select
Assume P=1orVia input portto specify the value of prediction error power.- If first input value is not 1
Select what you would like the block to do when the first coefficient of the LPC coefficient vector is not 1. You can choose
Replace it with 1,Normalize,Normalize and Warn, andError.
References
Orfanidis, S.J. Optimum Signal Processing. New York, McGraw-Hill, 1988.
Makhoul, J. Linear Prediction: A tutorial review. Proc. IEEE. 63, 63, 56 (1975).
Markel, J.D. and A. H. Gray, Jr., Linear Prediction of Speech. New York, Springer-Verlag, 1976.
Supported Data Types
Double-precision floating point
Single-precision floating point
See Also
| Levinson-Durbin | DSP System Toolbox |
| LPC to LSF/LSP Conversion | DSP System Toolbox |
| LSF/LSP to LPC Conversion | DSP System Toolbox |
| LPC to/from RC | DSP System Toolbox |