A New Compensating Method of Non-Ideal Lowpass Filters in Modulated Wideband Converter

Abstract

There are several non-ideal factors in the hardware implementation of Modulated Wideband Converter (MWC), which is an efficient sub-Nyquist system for sampling the sparse multiband signals. The non-ideal lowpass filter is one of these factors and can distort the reconstructed signal. In this paper, we concentrate on how to eliminate the impact of non-ideal lowpass filters and propose a new compensating method which can correct the non-ideal characteristic of actual lowpass filters. This solution remedies for the Fourier coefficients of samples in frequency domain with a bit more oversampling, compared to the standard MWC. The direct compensation in frequency domain is intuitive to acquire the Fourier compensating coefficients. And numerical simulations demonstrate that, this method can compensate many kinds of lowpass filter no matter what radical fluctuations and non-linear phases in the pass band of the filter.