Speech Processing with the Usage of Cosine Transform on the Basis of Synthetic DPCM

In the last years the methods of speech processing especially for cellular systems and Internet voice communication particularly with the use of discrete cosine transform (DCT), have been greatly developed. One of the most popular formats used for speech processing is PCM (pulse code modulation) format, which has a high processing accuracy. However, the restrictions of the usage of PCM codes are their long words and time-consuming multiply operations. In order to decrease the wordlength we can use DPCM (differential pulse code modulation), which has a similar resolution as PCM but operates on shorter word lengths. The efficiency of the usage of DPCM in speech processing can be improved by fast parallel shift operations instead of the multiplications. However, similar ways have not been studied enough yet. This work shows the possibility of the speech processing on the basis of DCT and parallel operations on DPCM codes