Study And Implementation Of Low Bit-rate Speech Coding And Decoding Based On Embedded System

With the development of technology, speech technique becomes more and more widely used in new generation of cell phone, PDA, home gateway, set-top box, and VoIP, etc. But because of the constraint of channel bandwidth and the attempt to broaden the communication capacity, low bit-rate speech coding technique is badly needed in embedded system application.ARM processor is small in size, low in power dissipation, low in cost and high in performance, and it has both 16 and 32 bit instruction set. ARM processor is widely used in the solution to 16/32 bit embedded RISC and it nearly occupy 75% of embedded RISC microprocessor market share.This paper focuses on the implementation of low bit-rate speech encoding and decoding based on embedded system. The coder and decoder adopt G732.1 recommendation, which is a standard of low bit-rate voice codec, proposed by the International Telecommunications Union (ITU). The system model and algorithms of encoding and decoding of G723.1 is analyzed in this paper, then a digital speech encoding and decoding scheme based on ARM is proposed and its implementation scheme is also discussed.