International Journal of Emerging Engineering Research and Technology
Volume 2, Issue 2, May 2014, PP 91-95
©IJEERT www.ijeert.org 91
Implementation of Speech Compression Using Linear Predictive
Coding (LPC) with Tms320c6713dsk and Comparison with Other
Platforms
Uday Mithapelli , Suraj P. Patil
Dept. of E & Tc, KJEI’s Trinity College of Engineering & Research,
Pune, India
Abstract: In recent multimedia system, people consider speed, power, and size very important. People want
the process to have very high performance and high quality, while consume only small amount of power. Beside
the development on better algorithm, special hardware design techniques can also help in increasing
performance. This project mainly focuses on the linear predictive coding algorithm on speech. The algorithm is
analyzed and implemented on DSP processor TMS320C6713 .
The implementation is done using Code Composer Studio(CCS) for which we also have a chance to evaluate
the effectiveness of the software in implementing the encoder from a hardware level perspective. This LPC
coding is having wide application in wireless communication and also used for accurate estimation of Speech
Properties.
Keywords: Linear Predictive Coding(LPC), DSP processor TMS320C6713,Code Composer Studio(CCS
3.1),Segmental Signal To Noise Ratio (SEGSNR) and Power Signal To Noise Ratio (PSNR )MATLAB platform.
1. INTRODUCTION
Linear Predictive Coding (LPC) is one of the
methods of compression that models the process
of speech production. Specifically, LPC models
this process as a linear sum of earlier samples
using a digital filter inputting an excitement
signal.
An alternate explanation is that linear prediction
filters attempt to predict future values of the
input signal based on past signals. LPC
“...models speech as an autoregressive process,
and sends the parameters of the process as
opposed to sending the speech itself” . It was
first proposed as a method for encoding human
speech by the United States Department of
Defense in federal standard 1015, published in
1984. Another name for federal standard 1015 is
LPC-10 which is the method of Linear
predictive coding that will be described in this
paper.[1]
Speech coding or compression is usually
conducted with the use of voice coders or
vocoders. There are two types of voice coders:
waveform-following coders and model-base
coders. Waveform following coders will exactly
reproduce the original speech signal if no
quantization errors occur. Model-based coders
will never exactly reproduce the original speech
signal, regardless of the presence of quantization
errors, because they use a parametric model of
speech production which involves encoding and
transmitting the parameters not the signal. LPC
vocoders are considered model-based coders
which means that LPC coding is lossy even if no
quantization errors occur.
Speech coder that is developed analyzed using
both subjective and objective analysis.
Subjective analysis will consist of listening to
the encoded speech signal and making a
judgment on its quality. The quality of played
back signal will solely depends on opinion of
listener. Objective analysis will be introduce to
technical access the speech quality and to
minimize human bias.[4]
The Objective Analysis will be performed by
computing between the original and coded
speech signal . Also speed of operating platform
in terms of second is also analyzed.
2. KEY FEATURES AND BASIC OPERATION
OF 6713 PROCESSOR
This project is implemented on TMS3206713
DSK kit. A Texas Instruments TMS 320C6713
DSP operates at 225 MHz It has 16 Mbytes of
synchronous DRAM
and512 Kbytes of non-volatile flash memory
(256 Kbytes usable in default configuration).
Digital signal Processing is one of the most
powerful technologies that will shape science
and engineering in the twenty first century.