Duration: 1:04:44

150 views

2

Voice telephony will remain a key service in mobile communication networks. As the audio frequency range is today still limited to the traditional telephone-bandwidth of about 3.4 kHz, there is a high potential to improve the audio quality and the speech intelligibility. Recent developments in speech-audio coding for HD-telephony (at least 7.0 kHz) and binaural telephony with spatial perception are presented. In the long transition period from today�s narrowband telephony to future voice audio communication, the acceptance of the new mobile HD-phones can be supported by artificial bandwidth extension, which is a mixture of pattern recognition, statistical estimation and speech synthesis. A particularly interesting variant is the bandwidth extension that works with methods of steganography (digital watermark technology). Furthermore it is shown that, by iterative source-channel decoding, the improved audio quality can be ensured even on highly disturbed mobile radio channels. The different concepts of coding, artificial bandwidth extension and iterative error protection will be explained and demonstrated by audio examples.