Determining the frequency spectrum of a multicomponent radio signal in a digital receiver with sub-sampling

An algorithm for registration and subsequent calculation (recovery) of the frequency spectrum of the signal using a digital receiver is proposed. The receiver is implemented as a multichannel device with parallel operation of channels in the downsampling mode with different sampling frequencies of ADC with the subsequent processing of these parallel channels spectrum in a digital processor – frequency comparator. Restoration of the spectral composition of the input signal from the totality of the spectra recorded in the channels is performed by a special algorithm. The receiver is broadband one: its working frequency band covers dozens of Nyquist zones. The use of this method allows to significantly simplify the block diagram of the receiver – an signals spectrum contents meter. The description of signal conversion in the receiver and the results of numerical experiments – modeling of its work on the examples of a multi-component input signals are given.

The development of the work involves a change in the simulated “input scenario”: adding noise with a controlled intensity to the input-deterministic signal and calculating the probability of errors in recovering the spectrum of the input signal at different signal-tonoise ratios at the receiver input.