The Voice Gateway Signal Processing Based On Arm

The signal transmited in the PSTN(Public Switched Telephone Network) can be divided into two categories basically: the DTMF signals and FSK signal which be modulated by carrier signal to carry data.The public telephone networks also use these two categories of signals for data communication between the remote telephone terminal, aiming to achieve a variety of intelligent functions through public telephone networks first have to be able to detect and generate FSK/DTMF signals. To sum up, the research for voice gateway signal DTMF/FSK transmitting in public telephone networks is particularly important.To further the application of DTMF/FSK signal ,we need to research reliable and stable DTMF/FSK generating and decoding algorithm, the formation of function is simple, voice gateway processing module is highly integrated.The transmission rate of voice gateway DTMF signal in phone terminal is slow, but DTMF signal has a good anti-interference, generally used for telephone tone dialing; FSK signal modulated by carrier signal to carrying the data is usually used for high speed communications occasions, such as Modem. The research of voice gateway signal processing system based on ARM aim to complete the voice signal DTMF identification and dialing, modulation and transimmiting of FSK signal , decoding support functions to the caller ID information.In the last, we designed software algorithms process of the whole system,and complete the gateway of voice recognization and signal transmission ultimately.Firstly, for a brief introduction about the system principle and functions;Secondly, for the control of the core of the hardware platform build on the ST's STM3210B EVAL evaluation board, the basis of a telephone interface circuit to complete the testing and simulation of ring hook and hang up, using Winbond's W681310 voice codec chip for analog voice to digital voice conversion;Finally, the software design are discussed in detail to illustrate the advantages of using Gozertel algorithm and explore the feasibility about ARM implementation DTMF/FSK signal detection and proposed DTMF/FSK soft decoding method, complete the corresponding algorithm process.