Comparative study on digital noise suppressors for PCM speech
Kiyosumi Yoshiya · Electronics and Communications in Japan (Part I Communications) · 1984
Abstract In PCM transmission systems a digital, click‐like noise due to bit errors is added to the demodulated speech. In former reports by the author an effective receiver side noise suppression system (SUNDER) was proposed which provides better error detection ratio and output S/N characteristic than other known error detection methods. the characteristics of the system for PCM speech containing background noise and for various binary codes were also published. the present paper considers a comparative study of the SUNDER and other proposed digital noise suppression systems, based on a computer simulation experiment of the output S/N improvement and other related characteristics in the case of PCM speech (8‐bit folded code, μ = 100 logarithmic companding) under the same error conditions. the results have shown that for error rates in the range of 10−5 to 10−2 the output S/N improvement by the SUNDER system is about 18 dB, which is higher by 8 to 9 dB than that by other systems.