Speech Coding Techniques for VoIP Applications: A Technical Review
Manas Ray, Mahesh Chandra · 2015
Voice over Internet Protocol (VoIP) is a revolutionary technology which is acting as a platform for the development of latest trends in modern communication world. The speech signal quality in VoIP is governed by the speech coding techniques employed. Currently various standard coders like FS-1015(LPC-10), ITU-G.711, ITU-G.726, FS-1016(ITU-G.728), etc. are used to digitize the speech signal. Modern research trends in signal processing are concentrating on the wavelet based compression techniques. This paper analyzes the performance of the standard codecs with various wavelet based codecs by statistical analysis of the coding capabilities of the codecs for English and Hindi language sentences spoken by a male and a female speaker. The performance is measured in terms of Compression Ratio (CR), Signal to Noise Ratio (SNR), Normalized Root Mean Square Error (NRSME) and Mean Opinion Score (MOS)