Undersampled Spectrum Reconstruction Using Multichannel Multifrequency Sampling

Signal undersampling is a technique used in digital signal processing where the sampling rate is less than what the sampling theorem requires. In this case, there is the effect of aliasing, which can lead to unacceptable distortion. The paper proposes a method to restore the spectrum distorted by aliasing. To do this, the signal is sampled in several channels with different sampling rates. All these frequencies do not satisfy the sampling theorem, so aliasing takes place in all channels. However, the spectrum distortions in the channels differ from each other. These differences are used to restore the spectrum. The paper presents an example of spectrum restoration in the case of three channels.