Research On Baseband And System Of Terahertz Wireless Communication Based On Direct Modulation

With the rapid development of communication and information technology,high-speed communication has become the research focus in the world,at the same time,the growing shortage of wireless communication bandwidth resources has become a key issue in limiting the rate of communication,in this context,terahertz wireless communication with its wide-band,high-speed characteristics caused by the concern of researchers from all walks of life.In this paper,the use of direct modulation based on the terahertz wireless communication technology,using FPGA to achieve wireless communication baseband control design.The terahertz source and modulator of direct modulation independent of each other,the biggest advantage of this modulation method is that the terahertz source and modulator can be independently studied,and the other can be flexible with different terahertz sources.The modulator used in the subject is the OOK amplitude modulator designed by the research group,the modulator has a high modulation rate,and can achieve high-speed modulation mode switching.Therefore,this paper builds a terahertz wireless communication system based on the direct modulation method,and systematic design and research the wireless communication baseband.The main contents and results of this thesis are as follows:1?This paper studies the overall technology of terahertz wireless communication system with direct modulation method,studies the access problem of external modulation devices and FPGA,analyzes the baseband hardware and software processing platform using FPGA direct modulation technology.2?Design the structure of the terahertz wireless communication system based on FPGA and introduce the basic working principle of the system,set up the hardware platform and software platform of baseband of wireless communication system,providing a basis for the implementation of baseband design.According to the working principle of the wireless communication baseband and the system requirements of the system requirements to determine the data transmission interface for the USB3.0 and GPIFII interface,the modulation signal is an analog signal during the transmission of the space and the system receiver needs to perform analog / digital(A / D)conversion on the analog signal,In this paper,the use of integrated ADC FMC150 sub-board and the master of the program to achieve analog signal data acquisition and A / D conversion.3?Combined with the basic theory of wireless communication baseband and system indicators,proposed the scheme of baseband data transmission controlled by the FPGA.First,complete the data transmission interface design,the system sender PC sends baseband data to the USB module,the FPGA receives the data and provide the baseband signal to the terahertz external modulator after performs some column baseband signal processing.System receiver first completes the reception and demodulation of the modulation signal,and then under the control of FPGA to achieve analog signal AD acquisition and A / D conversion,FPGA to complete the reconstruction of baseband signals and a series of baseband signal processing,finally,the baseband data is transmitted to receiver PC.In this paper,high-speed baseband joint test of terahertz wireless communication system with direct modulation is realized by using FPGA.The transmission of high-definition video image is observed in the experiment.