Study And Design Of Intersatellite Links Signal Acquisition And Tracking Processor

With the rapid development of the intersatellite links, the number of satellites are on the increase, the electromagnetic environment is more and more complex, at the same time,with the improvement of transmission, rateanti-interference ability and the continuous improvement of the on-chip processing and interactive technology, all brought great difficulties to intersatellite link between signal transmission, intercept and interference.how to extract the characteristic parameters of intersatellite link between signals and track accurately under the situation of the unknown priori knowledge, low signal-to-noise ratio, broadband and complex electromagnetic interference, is currently the research direction in the field of intersatellite link between signal against. No matter who first master the core technology of satellite communication links, who get the initiative of space in the future. Since the 1980 s, digital integrated circuit and microelectronic technology have entered a rapid development stage, the reliability of electronic components, integration, volume, power waste, etc have improved a lot, at the same time, with the rise of software radio theory and engineering application, all make it become a reality to design more efficient angle tracking receiver.Combined with the research background, it is for the intersatellite link between signals,V band, the maximum bandwidth of intermediate frequency signal is 300 MHz, the modulation types of signals are given priority to MPSK and MQAM, symbol rate is up to 150 Mbps. This paper designed the processor for capturing and tracking star signals,which is based on FPGA and DSP hardware platform. The TMS320C6713 B of TI company is the key signal processing part, the core algorithm is completed on it.Combined with the FPGA XC4VLX80 of Xilinx, EV10AS150 B ADC chip of E2 V,CDCE62005 low jitter clock chip of TI. Implement the extraction of the characteristic parameters of link signal and track accurately.This paper first introduces the application background and significance of this topic,make brief analysis of the current research of domestic and foreign. Then, according to the topic request, the overall scheme of the capture tracking processor is designed,demonstrates the feasibility of design scheme from the transmission attenuation, receiver sensitivity and signal to noise ratio was synthesized by means of single channel.Then, studys the key signal processing technology, which are involved in the high speed sampling, digital down conversion, extraction of signal characteristic parameter and angle error. The high speed sampling converted the input analog to digital quantity; The digital down conversion achieved the baseband processing of input signal using polyphase filter algorithm; The extraction of signal characteristic parameter completed the estimation of the carrier frequency, modulation types and information symbol rate.Studied carrier frequency estimation based on nonlinear change,modulation type identification based on cyclic cumulant, angle error extraction algorithm based on the method of single channel monopulse and a small number of bandwidth.Then, completed the construction of the capture tracking processor hardware platform, selection has made the detailed introduction to the device. Finally, completed the program design of the key signal processing algorithm, algorithm optimization and hardware testing,estimated the tracking capture time, analyzed the application of resource, the measured results comply with the design requirements. In the end of this article,summarizes the design of parts in need of improvement, propose the method of improvement, analyse the future development of the capture tracking processor, in general, with the rapid development and application of intersatellite communication,this topic is worth in-depth study.