Subjects: Geosciences >> Space Physics submitted time 2017-01-22
Abstract： In order to ensure quantum science experiments can be developed smoothly, a high data rate two-way link for Space-Ground microwave communication must be established. Via following the study on Consultative Committee for Space Data Systems (CCSDS) and taking into account the scientific requirements of microwave communication link for quantum science experiment satellite, the physical layer hardware architecture and modulation/demodulation algorithm of microwave communication link for the satellite are presented.The uplink modulation type of the microwave communication link is SRRC-OQPSK, which accord with CCSDS spectrum standard. The specification of uplink data rate is 1.024Mbps,. The downlink modulation type of the microwave communication link is SRRC-OQPSK/GMSK, and the data rate is 4Mbps. By compatible tests with several ground stations, we find that the sensitivity of carrier acquisition is superior to -100dBm, and AGC ability is greater than 43dB. Moreover, the bit error rate of actual transmission is superior to 1�0-9 as the received signal level is equal to -96 dBm. The measured results indicate that the physical layer design scheme of microwave communication link meets the requirements of space quantum science experiments.
Peer Review Status:
Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2016-05-13
Abstract： GMSK modulation plays an important role in space telecommunications. Local oscillator phase noise has significant influence on GMSK demodulation system. Some characteristics of phase noise and its math expressions on both time and frequency domains are analyzed. Furthermore, the simulated phase noise sequence is added to the GMSK modulation system to show how the different levels of phase noise affect the demodulation performance. The conclusions have deep reference value to optimize the GMSK demodulation system. This method to analyze phase noise and its effect can be extended to any modulation system.
Peer Review Status:Awaiting Review
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