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为减小边坡监测雷达系统中巨大的数据运算和传送压力，并充分利用Xilinx Kintex-7 FPGA内部富余的硬件资源，设计了针对调频连续波的地基合成孔径雷达回波数据的快速预处理系统。该系统利用FPGA的并行处理能力与流水线结构，结合Xilinx ISE14.7开发平台中AM/ROM、Divider、FFT IP核，实现了任意数量PRT信号相干积累、汉宁窗加窗滤波以及距离向压缩三项功能。经该系统处理后，在雷达回波数据到达DSP之前，雷达回波信号的信噪比得到了显著提高,距离向旁瓣得到了有效抑制，同时雷达系统的实时处理能力得到了极大的提升。 相似文献
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A full-duplex optical passive access scheme is proposed and verified by simulation, in which hybrid 64/16/4-quadrature amplitude modulation (64/16/4QAM) orthogonal frequency division multiplexing (OFDM) optical signal is for downstream transmission and non-return-to-zero (NRZ) optical signal is for upstream transmission. In view of the transmitting and receiving process for downlink optical signal, in-phase/quadrature-phase (I/Q) modulation based on Mach-Zehnder modulator (MZM) and homodyne coherent detection technology are employed, respectively. The simulation results show that the bit error ratio (BER) less than hardware decision forward error correction (HD-FEC) threshold is successfully obtained over transmission path with 20-km-long standard single mode fiber (SSMF) for hybrid downlink modulation OFDM optical signal. In addition, by dividing the system bandwidth into several sub-channels consisting of some continuous subcarriers, it is convenient for users to select different channels depending on requirements of communication. 相似文献
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