无人机测控系统中数控振荡器的FPGA实现与仿真

FPGA Implementation and Simulation of NCO in UAV Telemetry & Control System

无人机的测控系统要求数控振荡器(NCO)的频率分辨率高、相位噪声低、杂散小。在分析相位截断、幅度量化会导致NCO的输出产生杂散的基础上,提出了抖动信号注入与函数值校正的混合算法,并利用FPGA芯片实现了一种适用的频率、相位、抖动信号、校正因子等参数可调的NCO,取得了较好的整体性能。仿真结果显示:设计的NCO适合无人机的测控系统,并与理论分析相吻合。

In the UAV telemetry ＆ control system, it is required that the numerical control oscillator （NCO） having high frequency resolution and small spurious signal. On the basis of analyzing phase truncation and amplitude quantification, the hybrid algorithm of dither signal injection and function value correction is proposed. The applicable NCO that its parameters （ such as frequency, phase, dither signal and correction factor） are controllable is realized with FPGA. Simulation results indicate that designed NCO is suitable for UAV telemetry ＆ control system and consistent with theory analysis.