Verification On Digital Baseband Transmission Of Terahertz Wireless Communication

As an important direction for the development of future communication technologies,terahertz wireless communication provides an effective way to solve the current shortage of spectrum resources and high demand for wireless communication speed.How to improve the data rate of the terahertz wireless communication physical layer is a hot issue that has been studied for a long time.Based on the terahertz wireless communication,this thesis studies the waveform design of digital baseband and verifies it through hardware implementation and testing.The main work of the thesis includs following aspects:First,this thesis analyzes the baseband waveform requirements for terahertz wireless communications.Based on the point-to-point communication between the inter-satellite and the satellite-earth business scenario,the idea of high-speed terahertz communication is proposed,and the idea of parallel processing of baseband is proposed as well.Combined with the requirement of peak-to-average ratio of the system,the SC-FDE(Single Carrier Frequency Domain Equalizations)technology is used as the digital baseband process scheme;Characteristics of terahertz wireless communication are analyzed for channel feature,and its channel is mainly affected by large frequency offset and in-band fluctuation.The above analysis indicates the direction of the specific design of the digital baseband.Second,the thesis designs and simulates the terahertz wireless communication physical layer.A serial frame structure is designed for terahertz communication for the first.A parallel digital signal processing scheme is designed according to the serial frame structure and terahertz data rate requirement.Then,the transmitter processing scheme is designed for parallel structure and terahertz communication requirements with parallel structure and terahertz channel.The special structure and method of receiver digital signal processing are designed in the therahertz channel background.Finally,the system is simulated by simulating the frequency selective fading characteristics of the terahertz channel,and the performance curves of three modulation methods are given.Third,this thesis depict the implementation of the entire digital baseband system based on a software defined radio platform.The overall implementation architecture of the system is described at first,then we explaines the module interconnection scheme and inheritance relationship.Namely,we describe the hardware micro-architecture of the key modules of the system in detail,and explaine the parallelization processing scheme is.The optimization design method in the implementation is expounded in the thesis,through resource analysis and evaluation proves the rationality of hardware implementation.Fourth,we verify the performance of the terahertz wireless communication digital baseband by actual test.The transmitted signal bandwidth reaches 1.84GHz.Under the condition of cable coupling direct connection,the system data rate reaches 9.6Gbps,and the bit error rate is less than 10-6 when Eb/N0 is 15.3dB.In the terahertz-coupled testing scenario,it is difficult to achieve the data transmission capability of 9.6Gbps under the condition of single channel.The system scheme is modified to transmit signals with two channels,and the final data rate reaches 12.8Gbps,which can complete the high-quality transmission of ultra-clear video.This thesis proposes a digital baseband waveform scheme that meets the needs of terahertz wireless communication,this waveform features high bandwidth and high data rate.Through theoretical simulation,hardware implementation,and atmospheric point-to-point measurement,the verification of this scheme is completed,which has engineering reference significance in the development of high-rate terahertz wireless communication.