الفهرس | Only 14 pages are availabe for public view |
Abstract THIS THESIS REPRESENTS AN EFFICIENT METHOD FOR REDUCING THE QUANTIZATION NOISE FOR CODING SPEECH SIGNALS AT LOW BIT RATS.THISMETHOD HAS GAIND INTEREST DUE TO ITS EASE OF IMPLEMENTATION AND CHANNEL NOISE ROBUSTNESS COMPARED TO OTHER DIGITAL CODERS. ADAPTIVE DIFFICIENT SCHEMES FOR DIGITAL ENCODING OF SPEECH. DIFFERENT ALGORITHMS HVE BEEN PROPOSED FOR INCREASING OF DINAMIC RANGE FOR A GIVEN VALUE OF SIGNAL-TO-QUANTIZATION NOISE RATIO (SNR). THE PREDICTOR IS A VITAL PART OF THE OVERALL SYSTEM. THIS THESIS ALSO INVESTIGATES THE USE OF SECONDorder PREDICITION TO INCREASE THE SNR FOR SEVERAL ADPCM SYSTEM AT LOW BIT RETES SPECHIALY JAYANT ADAPTIVE QUANTIZER JAQ. INADDITION A STUDY AND COMPARSION HAS BEEN DONE BETWEEN THE DIFFERENT ADAPTATION SYSTEMS. MOREOVER COMPUTER SIMULATIONS HAVE BEEN PERFORMED USING THREE DIFFERENT TYPES OF INPYT SIGNALS, SINUSOIDAL SIGNAL, RANDOM SIGNAL AND REAL SPEECH SIGNAL. |