Hardware Design And Implementation Of Train Voice Amplifier Unit Based On Zynq

With the application of multimedia technology in modern train,the information content of train communication has increased rapidly,thus the rail transit puts forward new requirements about the train passenger broadcasting system,including audio performance index,automatic volume control,stability and security,etc.In recent years,with the rapid development of communication technology,especially Ethernet technology,train radio technology has been a great development.In view of the above requirements,this thesis designs a train voice amplifier unit based on Zynq.It can not only encode and decode various formats of audio signals,but also can shunt the output of high frequency and low frequency components of the audio signal,thus improving the audio performance indicators.Whereafter,this thesis uses the noise detection and automatic gain control function to achieve the volume of automatic control.In addition,two Gigabit Ethernet communications and analog audio channels are used to maintain normal broadcasts for communication failure.Finally,magnetic induction current detector and voltage detection module are used to monitor the changes of output current and voltage,through the changes of impedance to detect the speaker network faults.Firstly,this thesis introduces the development process of train passengers broadcasting system and basic knowledge of the power amplifier and digital audio format,then according to the specific needs of the train voice amplification unit,this thesis proposes a design scheme based on CPU plus FPGA architecture of the processor,audio codec chip TLV320AIC3106 IZQE and VS1063,digital amplifier chip TPA3118D2 DAPR,magnetic induction detection chip TLI4970-D025T4 and RS485 bus.Next,this thesis introduces the schematic design of each function module in detail.Whereafter,based on electromagnetic compatibility and signal integrity knowledge,this thesis introduces the PCB stack selection,the basic principles of layout and wiring and DDR3 simulation test.Afterwards,the thesis describes the basic hardware test,function test and reliability test of the board and gives the test results.At last,the conclusion is given and the future improvement suggestions are put forward.