Design of Broadband Compressed Sampling Receiver Based on Concurrent Alternate Random Sequences

Modulated wideband converter (MWC) is a multi-branch sub-Nyquist sampling structure for processing the spare wideband signals. By mixing with a periodic pseudo-random bit sequence (PRBS), each branch of MWC compresses the information of the input signal into a narrow baseband which can be sampled at low speed. Based on the several sampling sequences, the input signals can be reconstructed by compressed sensing (CS) optimization algorithms. However, the classic MWC (C-MWC) still consumes a lot of hardware resources because of its complex structure. Especially when the spectrum is blind, the total sampling rate is required to be four times the Landau rate for joint sparse reconstruction. To solve this problem, this paper proposes alternate MWC (A-MWC). A-MWC replaces the periodic PRBSes with two sets of alternating PRBSes and uses a trigger to synchronize the PRBSes and the sample sequences. Based on a reasonable assumption that the input signals are the wide-sense stationary (WSS) signals which have the same power spectral density (PSD) in each time slice, this paper reduces the requirement the sampling rate for blind joint sparse reconstruction to twice Landau rate successfully. Both simulation and experiment prove that A-MWC reduces the number of branches required for blind reconstruction without reducing the quality of the reconstructed signal.