Ultra High-speed Real-time Communication System Based On Software Defined Radio

RF communications technology is difficult and hot in the whole electronic system design from its birth. The bandwidth of the traditional radio communication system based on hardware is limited, it has been increasingly unable to fully meet the needs of the current development of various industries, particularly in the space field. Because of our country’s development in the space industry in recent years, the requirements of satellite communication rate is getting higher and higher, especially the emergence of the relay satellite, need for customized ultra high-speed communication system to meet the entire satellite relay link construction.This paper proposes a method to achieve ultra-high-speed real-time data communication system based on software radio. For ultra high-speed communication system based on software radio technology in the design of the construction of the hardware platform and software algorithm, The simulation of the algorithm, the development and implementation of the system hardware,finally completed the prototype development. The performance and the parameters of the system are verified by various instruments.The software radio system is generally divided into two kinds. One is the realization of the software radio algorithm with high speed computer. This method is easy to implement for the realization of the software algorithm, but the power consumption of the system is higher, and the operation speed and the calculation efficiency are lower. Another way is to use the FPGA chip as the core of the system, so that all the communication algorithm can be realized in FPGA in a hardware way, use space for time. The system has a higher final operation rate and the power consumption of the system is lower, but the development of the system is complex. And because FPGA is generally programmed by HDL language, this language is different from other computer programming languages. This increases the difficulty of the algorithm, making the development cycle and the development costs increased.In this paper, a software radio realization method is proposed, which is based on NI FlexRIO and Labview FPGA. Reduce the difficulty of the system, shorten the development cycle, save the system development costs. And it got the higher technical index in the final prototype.This paper first takes the commonly used modulation and demodulation algorithm of satellite communication has made the theoretical analysis. Communication system described in this paper supports BPSK, QPSK, SQPSK, UQPSK,8PSK. In the 8PSK communication mode, the communication rate can reach the highest 800Mbps.Then in this paper, the system of transmitter and receiver hardware platform structures and software algorithm has made the detailed introduction.In this paper, the hardware platform with FPGA as core device platform realization algorithm, by using NI FlexRIO and FLexRIO’s adapter module, and by using PXIE bus to control the FlexRIO and other modules equipment to complete the whole system hardware platform.This paper describes the modulation and demodulation algorithm of the whole system, including the modulation system of high speed serial and transmitter module, phase searching module, high speed parallel phase digital filter module, the receiver demodulation system of bandpass sampling module, digital down conversion module, AGC module, carrier estimation module, timing recovery, carrier recovery module and so on. The simulation analysis of the core algorithm, and using Labview FPGA software on FlexRIO FPGA platform to realize the algorithm.Finally, this paper also will eventually realize the prototype debugging demodulation part made a detailed test, and presents the final results and test data.