Design Of High-reliability Frequency Shift Signal Receiving And Demodulation Device

Nowadays,my country’s railway industry is developing rapidly.The increasing speed of high-speed railways and the increasing density of trains impose higher technical requirements on the control of trains by the current railway sector in my country.By consulting a large number of relevant technical documents,analyzing the current development status of the main railway signal demodulation methods at home and abroad,discussing the system principle and technical indicators,the reception and demodulation of the track frequency shift signal is the main research direction of this article.At the same time,this paper also analyzed and compared the advantages and disadvantages of the hardware design scheme and demodulation algorithm,and worked out a solution for the design of a highly reliable frequency shift signal receiving and demodulation device.The content of the plan mainly includes the formulation of the hardware plan,the selection of the software demodulation algorithm,the compilation of the software program for receiving and demodulation,and the feasibility of the plan through simulation in the corresponding software environment.The main research contents of this paper are as follows:In terms of hardware system,this article compares the performance of industrial-grade DSP processors that are widely used in the current market,and chooses the DSP processor TMS320377 S with excellent demodulation speed and high demodulation accuracy as the main control chip.In order to achieve high-reliability signal demodulation and reception,this article adopts a dual-channel simultaneous signal reception and demodulation design scheme,and the hardware design of the two channels is the same.The main components of the hardware circuit mainly include three parts: signal conditioning circuit,analog-to-digital conversion circuit,data processing and communication interface circuit.Among them,the signal conditioning circuit is mainly composed of a voltage follower,a low-pass filter,a high-pass filter,a voltage amplifier,and an AGC circuit.The communication interface circuit adopts an isolated RS-485 communication interface to ensure the reliability of data transmission.In terms of software design,it mainly includes the two algorithms of ZFFT and wavelet transform with higher stability and reliability as the demodulation algorithm,and the demodulation operation is performed on the two channels respectively.After data verification,the two algorithms can be obtained within the error range.The signal demodulation work is completed with high precision inside.In this paper,the high-reliability frequency shift signal receiving and demodulation device is designed in detail from the hardware and software respectively.With DSP as the core processor,dual-channel simultaneous reception and demodulation,and data transmission through an isolated communication interface,so as to achieve High reliability of the device.Two algorithms of ZFFT and wavelet transform are respectively applied to the demodulation operation of the track frequency shift signal of the two channels,and finally,within a reasonable judgment range,a reliable signal demodulation result is obtained.Finally,the design analysis and testing of each functional module of the system are completed,and the overall system is debugged and verified,which proves the correctness of the high-reliability frequency shift signal receiving and demodulation system designed in this paper.