DSP Blockset

LSF/LSP to LPC Conversion

Convert line spectral frequencies (LSFs) or line spectral pairs (LSPs) to linear prediction coefficients (LPCs)

Library

Estimation / Linear Prediction

Description

The LSF/LSP to LPC Conversion block takes a vector or matrix of line spectral pairs (LSPs) or line spectral frequencies (LSFs) and converts it to a vector or matrix of linear prediction polynomial coefficients (LPCs). When converting LSFs to LPCs, the block outputs match those of the lsf2poly function.

The inputs to the block can be in one of three formats that you must indicate in the Input parameter, which has the following settings:

• LSF in radians (0 pi) -- Vector of LSF values between 0 and radians in increasing order. Do not include the guaranteed LSF values, 0 and .
• LSF normalized in range (0 0.5) -- Vector of normalized LSF values in increasing order, (compute by dividing the LSF values between 0 and radians by ). Do not include the guaranteed normalized LSF values, 0 and 0.5.
• LSP in range (-1 1) -- Vector of LSP values in decreasing order, equal to the cosine of the LSF values between 0 and radians. Do not include the guaranteed LSP values, -1 and 1.

Dialog Box

Output

Specifies whether to convert LSP in range (-1 1), LSF in radians (0 pi), or LSF normalized in range (0 0.5) to linear prediction coefficients (LPCs).

Supported Data Types

• Double-precision floating point
• Single-precision floating point

To learn how to convert to the above data types in MATLAB and Simulink, see Supported Data Types and How to Convert to Them.

Reference

Kabal, P. and Ramachandran, R. "The Computation of Line Spectral Frequencies Using Chebyshev Polynomials." IEEE Transactions on Acoustics, Speech, and Signal Processing, Vol. ASSP-34 No. 6, December 1986. pp. 1419-1426.

See Also

LPC to LSF/LSP Conversion	DSP Blockset
lsf2poly	Signal Processing Toolbox

Also see Linear Prediction for a list of all the blocks in the Linear Prediction library.

LPC to LSF/LSP Conversion

LU Factorization