GPS卫星信号模拟器中频信号处理与实现

利用数字内插、数字滤波、A/D(Analog／Digital)变换等软件无线电方法,建立GPS卫星信号模拟器中频信号处理的数学模型,提出了数字IF(Intermediate Frequency)的实现方法,且在matlab中进行了中频电路建模、优化和验证,完成了从数字基带信号处理到模拟中频信号生成.电路实现时尽量降低信号处理频率,缩小高频信号处理范围.利用verilog在ISE6.3中完成了数字中频模块的设计和仿真,对仿真输出的数字序列进行FFT(Fast Fourier Transform Algorithm)频谱分析,并在FPGA(Field Programmable Gate Arrays)中实现.

Implementation of IF signal processing in GPS satellite signal simulator

With the technique of software radio in digital interpolation, digital filtering, A/D(analog/digital) converter, a mathematic model for signal processing of digital IF(intermediate frequency) in the GPS satellite signal simulator was established, and the approaches achieving the practical hardware design was implemented. The algorithm and design model for the circuit implementation was verified and optimized with Simulink in Matlab, the processing from digit base-band signal to analogue IF signal generation was achieved. The signal processing frequency was reduced to the best of our abilities for the circuit, and the processing area in the board for the high frequency signal was minimized. With the Xilinx′ ISE development tool and FPGA(field programmable gate arrays) using Verilog, the design and emulating of digital IF was implemented,and the digit signal was also analyzed with FFT(fast Fourier transform algorithm) frequency spectrum.