"风云二号B星"原始云图数据解调技术

“风云二号B星”气象卫星的原始云图数据是时分复用的突发载波调制信号,本文就其特殊的预告码对于载波恢复电路捕捉性能的影响进行了分析,并对具有不同类型和带宽的低通滤波器的载波恢复电路性能进行了仿真。结果表明,理论上最优的积分泄放检测滤波器将可能使突发载波的捕获无法实现。论文针对不同滤波器带宽的误码率性能进行了仿真,结果表明基带5MHz带宽的FIR滤波器在突发载波模式下,可以获得比4MHz带宽更好的误码率性能。最后给出了一种经过优化的载波恢复和检测电路,并成功应用于工程实践中。

Demodulation of the Nephogram Signal of FY-2B Meteorological Satellite

The nephogram signal of FY-2B meteorological satellite is a burst QPSK modulated carrier, and the effect of the special preamble on the carrier recovery loop is analyzed in this paper. The performance of carrier recovery loop with baseband filters of several types and different bandwidth is analyzed, and it is shown that the optimum integral and dump filter for rectangle wave will lead to loss capture of carrier probably. Simulations on BER performance with different filter bandwidth show that the BER with the baseband FIR filter of 5MHz bandwidth is superior to that of 4MHz bandwidth in the mode of burst carrier. Finally, the optimized carrier recovery and detection circuits are formed and applied in the FY-2B ground receiving station.