A real-time IMT-2000 audio transmission system

For real-time audio streaming services over next-generation mobile phone systems, such as live concert broadcasting and radio relaying, we have developed a realtime IMT-2000 audio transmission system. This system consists of a real-time encoder and a portable real-time decoder, which are both based on fixed-point DSP chips. TWINVQ technology is used for audio compression, and a scheme to protect audio data against bit-errors was designed based on error sensitivity observations. Self-synchronization and adaptive error concealment are carried out at the decoder. We confirmed that the system can transmit high-quality stereo audio samples at 32 kHz with a total bit rate of 64 kbit/s over a simulated IMT-2000 channel. We also checked that this system can connect to a real IMT-2000 experimental network, and found that it is easily applicable to various audio streaming services