Title :
Variable rate speech coding techniques for the DECT system
Author :
Torres-Guijarro, Soledad ; Sanchez-Perez, R. ; Casajus-Quiros, F.J.
Author_Institution :
Dept. Inf., ETSI Telecommun., Spain
Abstract :
Variable rate coding techniques are proposed to improve the speech quality of the DECT system in poor channel conditions. The basic idea is to estimate in advance the quality of the channel, and subsequently select the best source-channel rate combination. The channel quality is predicted from the characteristics of the signal received in previous frames. The introduction of G.727 variable rate embedded speech coder, combined with FEC codes provides the rate adaptation. Objective quality measurements demonstrate the possibilities of this approach
Keywords :
channel coding; cordless telephone systems; forward error correction; speech coding; speech intelligibility; variable rate codes; ADPCM; DECT system; FEC codes; G.727 variable rate embedded speech coder; channel coding; channel conditions; channel quality estimation; objective quality measurements; rate adaptation; received signal characteristics; source-channel rate; speech quality; variable rate speech coding; Bit error rate; Decoding; Demodulation; Forward error correction; Propagation losses; Pulse modulation; Speech coding; Switches; Telecommunication standards; Telephony;
Conference_Titel :
Electrotechnical Conference, 1998. MELECON 98., 9th Mediterranean
Conference_Location :
Tel-Aviv
Print_ISBN :
0-7803-3879-0
DOI :
10.1109/MELCON.1998.699314
