The Broadvoice Speech Coding Algorithm

This paper describes the BroadVoice® speech coding algorithm, which has been standardized as PacketCable™, SCTE®, and ANSI standards for VoIP cable telephony. The BroadVoice family of codecs includes a 16 kb/s BroadVoice 16 narrowband codec and a 32 kb/s BroadVoice32 wideband codec. BroadVoice is based on two-stage noise feedback coding with vector quantization of excitation and is optimized for low delay, low complexity, and high quality. It has an algorithmic delay of merely 5 ms and a complexity of only 12 and 17 MIPS for BroadVoice16 and BroadVoice32, respectively. The speech quality of BroadVoice16 is better than that of G.728, G.729, and 32 kb/s G.726. The speech quality of BroadVoice32 is better than that of 64 kb/s G.722.