Dynamic Pre-compensation of Memory Nonlinear Distortion for High-Speed Signal Generator Based on Volterra Inverse

The spectral purity of input signal is extremely important for exciting the device-under-test in high-speed broadband applications. To improve spurious-free dynamic range of signal generator, a dynamic nonlinear pre-compensation method based on the Volterra pre-distortion filter is developed to compensate memory nonlinearities of the signal generator. The filter coefficients are iteratively identified and updated to track the changes of the system´s time-varying characteristics by employing an adaptive Volterra kernel identification method. With the increase of spectrum components contained in stimulus signal, the Volterra filter needs the longer memory and the lower order, and vice versa. So the amount of the calculation will keep in an acceptable level by proper setting. The results show good performance, moderate complexity and high availability.