Research And Key Technology Verification On Satellite-earth Communication Transmission Waveform Of 800Mbps Throughput

Satellite-earth communication has the advantages of wide coverage,high information rate,and being unaffected by the terrain environment.Satellite-earth communication has played a vital role in the context of emergency communication and communication in remote areas.With the increase in demand and business expansion,high-speed broadband satellite-earth communication has become the development trend of satellite-earth communication.In order to implement broadband transmission under the current spectrum resource constraint,only the high-frequency centimeter wave band can be used.Therefore,satellite-earth communication needs to overcome the weather effect,multipath effect and Doppler effect of the centimeter wave channel.Based on the application scenarios of Ka-band?26.5 GHz⁴0 GHz?satellite channels and the requirements of specific indicators,this paper studies a multi-carrier modulation scheme using Orthogonal Frequency Division Multilexing technology and implements a broadband satellite-earth communication link with the 800 Mbps throughput rate on the Field Programmable Gate Array.The specific work of this paper is as follows:Firstly,the paper introduces the history and development trend of satellite-earth communication,and summarizes the modulation techniques commonly used in satellite-earth communication,including orthogonal frequency division multiplexing technology and digital frequency conversion technology.Combined with the implementation of specific transmission waveform,the challenges in the design of satellite-earth communication link are analyzed.Secondly,the Ka-band channel characteristics and channel model are analyzed,and a broadband high-speed satellite-earth communication link design scheme using Orthogonal Frequency Division Multilexing modulation is studied based on the link index requirement.At the same time,performance simulation of the communication link is performed in the simulation software.When the link has a maximum Doppler frequency shift of 450 k Hz and a maximum multipath delay of 200 ns,E_b/N₀ is 6.6 dB,and the bit error rate is less than10^-6.Thirdly,based on the design of communication link,the implementation of Field Programmable Gate Array function is achieved by software radio platform.The overall implementation structure of the transmitter link and the receiver link is designed.The implementation composition,interface and timing arrangement of parallel IFFT/FFT unit and parallel digital frequency conversion unit are mainly designed.The integration,debugging and implementation of the transmitter link and the receiver link are completed.Finally,according to the requirements of the communication link,the internal performance test of the Field Programmable Gate Array for communication link is completed,and the test results are compared with the index requirements.Participate in the system test and complete the overall system functional test and performance test including the upper computer,digital baseband-IF link,RF channel and antenna channel.The test results meet the indicator requirements.In this paper,a multi carrier modulation scheme using Orthogonal Frequency Division Multilexing technology is studied for the Ka-band satellite channel.A broadband satellite-earth communication link with the 800Mbps throughput rate is implemented on Field Programmable Gate Array,and it participates in system test.It provides a reference for the development of high-speed broadband satellite communication.