基于AD9361的中频幅相误差自校准方法

Self-calibration Method of Intermediate Frequency Amplitude and Phase Error Based on AD9361

基于AD9361实现的中频多输入多输出(MIMO)通信系统中,由于多芯片间本振锁定时存在随机相位差,且经过滤波及模数/数模转换等处理,导致多通道间存在幅相误差。针对该问题提出一种收发通道幅相误差自校准方法。该方法通过选择一定长度的采样数据,对其进行快速傅里叶变换(FFT),并进行幅相误差估计,可以方便快捷地实现通道间幅度相位误差的自动校准,且校准精度高,信噪比性能好。校准后通道间一致性较好,从而保证了后续波束成形的方向图性能。

In intermediate frequency(IF)multiple input multiple output(MIMO)communication system based on AD9361,due to the random phase difference of local oscillator(LO)locking between multiple chips,as well as filtering,analog to digital/digital to analog conversion and other processing,there are amplitude and phase errors between multiple channels.To solve this problem,self-calibration method of transceiver channels is introduced.By selecting sampling data sequence and performing fast Fourier transform(FFT)calculation,this method can conveniently and quickly realize the automatic calibration of amplitude and phase errors between channels,with high calibration accuracy and good signal-to-noise ratio performance.Good consistency can be obtained between channels after calibration,so as to ensure the performance of following beam forming.