Digital Implementation Of The Receptor In Civil Aviation Communication Radio

Air traffic control refers to the command and dispatch of aircraft take-off and landing processes by ground control personnel through dedicated communication systems.It is an effective means to ensure aircraft flight safety and improve flight efficiency.The radio station is the main equipment in the communication system,and achieve the send and receive function.The receivers in traditional radio stations use Surerheterodyne structures,which are mainly composed of analog devices.The technical level is relatively backward.The indicators are greatly affected by the aging factors of components,the functions are single,it is difficult to upgrade,and the maintenance and repair process is cumbersome.They are gradually eliminated.With the development and application of the Software Definitional Radio(SDR)technology,it is replaced by a receiver composed of digital chips such as A/D conversion chips,DSP processing chips,and MCU control chips.Its main function is to write program software in DSP and MCU.Therefore,the performance indicators are better,more stable,and have strong flexibility.The purpose of this paper is to design the receiver based on the principle of intermediate frequency band pass sampling in SDR theory and to digitize the receiver in the radio,in order to better applied in civil aviation ATC communication systems.In this paper,the receiver is designed with band pass sampling,direct digital frequency synthesis and digital orthogonal demodulation technology.First,the signals received by the antenna are selected,amplified,and converted down to455 kHz.Secondly,the intermediate frequency signal is sampled with band pass to achieve A/D conversion;Finally,the digital signal processing chip TMS320VC5509 A completes digital downconversion and orthogonal demodulation,controls the D/A converter output the audio,and the MCU chip NUC140 L to achieve the control of the frequency synthesizer and the monitoring of the entire machine state.This paper is divided into two parts,the first is to explain the principle of the design and the technology used;The second is to complete the design of the receiver system structure,hardware circuit design,simulation,and software design,and strictly control the design,assembly and debugging of the product,and complete the machine implementation.After testing,the whole machine index is higher than the requirements of the civil aviation industry standard for receivers in radio products.The results show that it is feasible to digitize the receiver by using the intermediate frequency band pass sampling structure.