Key Technologies And Verification Of 300GHz Long-distance Wireless Communication

Terahertz wave has the advantages of large bandwidth and good concealment,so it is considered to be a potential technology.But so far,when the classical RF modulation method is applied above the 300 GHz band,the output power of the amplifier will be insufficient,which makes long-distance wireless communication very difficult.In this thesis,on the premise of this background,the frequency multiplier is used as the last-stage device in the RF transmission part,which can not only improve the output power of the last stage,but also reduce the performance requirements of the amplifier.On this basis,this thesis focuses on the digital baseband signal processing technology in 310 GHz long-distance wireless communication system,and demonstrates the feasibility of the technical scheme through simulation analysis and experimental testing.The main work of this thesis is as follows:First,according to the communication application scenario of this thesis,it is analyzed from two aspects: performance requirements and functional requirements.In order to meet the performance requirements,the technical specifications of 310 GHz long-distance wireless communication are analyzed and evaluated,and the physical layer baseband signal processing scheme is designed according to the analysis results.In order to meet the functional requirements,the digital baseband signal processing part uses programmable system-on-chip architecture to obtain better flexibility and extensibility.Secondly,a low complexity frequency tripler linearization method suitable for long-distance terahertz wireless communication is proposed.The advantages and disadvantages of the existing memory polynomial predistortion methods and fundamental demodulation methods are analyzed,and then the influence of frequency tripler on the amplitude and phase of broadband signal is deduced.In the end,a low complexity predistortion method is proposed in this thesis.the effect of predistortion signal bandwidth on reception performance is studied by simulation.Thirdly,the whole digital baseband signal processing system is realized by Xilinx FPGA.The basic flow of signal processing is introduced,then the design and implementation of the bus in the baseband signal processing part is described in detail,and the implementation process of the key algorithms in the baseband signal processing unit is described.Finally,the equivalent experimental test of QPSK signal is carried out in 220 GHz band,and it is found that the receiving SNR is 16.2dB and the bit error rate is below,which meets the requirements of demodulation.The experimental results in terahertz band prove the feasibility of the frequency multiplier as the final RF device,and also show that the tripler linearization method proposed in this paper has good practicability.In this thesis,a digital baseband system suitable for long-distance wireless communication in 300 GHz band is designed,and the communication system scheme is verified by theoretical analysis,algorithm simulation,hardware implementation and experimental testing,which is of great reference significance to the engineering implementation of long-distance wireless communication in 300 GHz band.