Research On Short - Band Frequency Synthesis And Remote Control Technology

With the continuous development of electronic science and technology, direct digital frequency synthesis technique has been used more widely. For example, in elecommunications, radio and television, aerospace, radar, satellite positioning and other fields.In this paper, according to a radio and television company’s needs, to design a set of short wavelength simulcast carrier signal synthesis system with remote debugging fiinctions,which is based on the theory of direct digital frequency synthesis technology and combined with embedded system.After considering hardware circuit design of the direct digital frequency synthesis chip and software implementation, according to the system needs to choose Embedded solutions of ARM9 and embedded Linux systems.At the time of project implementation, using S3C2440 as the main controller, his main purpose is that making circuit of the frequency synthesizer to output specified frequency and amplitude of signal, communications with a remote PC to achieve good human-computer interaction, collected the value of peak to peak of output signal by ADC, receiving value of FPGA frequency measurement,setting and displaying frequency and amplitude on LCD. acquiring and compressing the image.In remote communications, consider the company’s needs to select PSTN as the communication network, and according to the characteristics of this system and the communication mode to design a set of protocol in line with the communication of the system.Complete telecommunications portion of the programming on the basis of this agreement and realize the remote control of system. When the software is designing, write function interface of each module separately.to make full use of system resources, create a thread in the primary process,which is to process the task simultaneously.Finally, complete the entire system software design and system can be very good to complete the task after debugging.