Algorithm Of Fuzzy Control Delta Modulation In Speech Coding Based On DSP

With the integration of multimedia communications to keep our life, speech coding plays an increasingly important role. At present, there is a broader application of waveform coding and the parameter coding and hybrid coding, although parameters of coding and hybrid coding have on the advantages at coding rates, but for its decoding restored voice's nature is low and high complexity algorithm for real-time processing so they have limitations, for waveform coding circuit has easy hardware implementation, strong interference capability and Security, so it is still very widely used in military communications and other fields, now there is a widely used algorithms such as DPCM, ADPCM,ΔM. the main principle of it is to code with the difference between forcasting value and the actual value .the changes ofΔin the predictor are dependent on the precise mathematical model . which still causes severe slope overload noise or distortion for some particularly high rate of change of the signal.To address these issues, come up with an algorithm—fuzzy delta modulation algorithm using fuzzy control theory, which needn't to determine the accurate mathematical model of the process, that is put the difference between Predictive value and the actual value as input , then by application of fuzzy control theory to predict the difference (e(n))between the value of prediction and the actual value and the difference (Δe (n)) between e (n) and e (n-1) in fuzzy way , get a a series of fuzzy control through fuzzy inference based on fuzzy control rules .then get precise value of control output ofδthrough fuzzy theory. Select the parameters of the initial adoption of a reasonable value, simulate and analysis of its performance on matlab, in order to further test this algorithm in real-time processing capability, at last migrate this algorithm to a powerful digital signal processing capability of DSP chip TMS320C5402 development board as the core, the results show that this algorithm in the DSP codec better effect: the volume ofδsize changes automatically with the voice signal amplitude changes which make the forecast better track the rapid changes in the signal waveform, it has not only the advantage of ADM, but also a better SNR performance and more dynamic the scope, fulfill the basic realization of the 'transparent' coding, then achieve the design requirements.