The human voice communication through GSM has become most important part of life. The voice speech requires encoding and decoding of the signal. It determines the quality of recovered speech and the capacity of the system. In Global System for Mobile communication (GSM) wireless system, bandwidth is precious goods and telecom service providers are continuously met with the challenge of accommodating more users within a limited allocated bandwidth. Low bit rate speech coding offers a way to meet this challenge. If the bit rate of the speech coding is low then the coder will be deliver quality speech, the more speech channels can be compressed within a given bandwidth. Earlier, the Code Excited Linear Prediction (CELP) coding technique has been used to meet this challenge.