Low complexity speech coder for personal multimedia communication

In personal multimedia communication systems, portable terminals are used to transmit many types of digital data such as coded speech and images simultaneously. The requirements for the speech coder used in these systems are: (1) low bit rate transmission of coded speech and (2) low computational complexity for low power consumption. This paper presents a low complexity, medium bit rate speech coding method suitable for these systems. The coder is based on CELP (code excited linear prediction). It employs two schemes to achieve low complexity: moving average scaler quantization and algebraic code search with orthogonalization. The bit rate of the proposed speech coder is 9.3 kbit/s and its computational complexity is about 3.5 MOPS. The performance of the coded speech is equivalent to that of ITU-T G.726 at 32 kbit/s.