A Design Of Telephone Terminal In Vehicle Based On SOPC

The environment of the calls in armored car was extraordinary foul and seriousnoisy. While they fighting with the enemies，It was very difficult to discoursecommunication whether the passengers converse with each other or communicate withthe outside in the vehicle，because of the voice signal’s signal-to-noise ratio is very low.So that we need to design a telephone terminal.In order to solve the problem, this dissertation designs a telephone terminal. Theinvestigation and realization of this thesis as follows:1) We set up a hardware system based on SOPC. In this paper, we use the virtex4FXwhich is the series of Xilinx to set up the hardware circuit. The chip of Virtex4FXitself has CPU and logic circuit. The CPU handles all the connection of voice andthe voice’s carry packet processing. The logic circuit mainly completes the data intoa complex interface of circuit.2) With the EDK which is the SOPC’s development tools of Xilinx, we set up a intactSOPC system. And we use the language of VHDL to realize logic circuit completetreatment of every interfaces.3) The dissertation analysed the interior noise of armored car to find out the identity ofnoise. We use the algorithm of speech enhancement to extract voice from the yawp,so that we can gain the point of improve the signal-to-noise ratio. In this paper,through using the improved spectral subtraction to decrease noises, and making usethe method of real-time update noise sample to apply noise environment better.Through using the MATLAB to make a well result of simulation in the laboratory,then we can transplant the algorithm to DSP to do real-time application.4) Finally we test the system simply, through the test to discover and solve problems inactual use. So that we can make it to achieve a better performance.