Wideband Sparse Signal Acquisition With Dual-rate Time-Interleaved Undersampling Hardware and Multicoset Signal Reconstruction Algorithms

A new undersampling-based dual-rate signal acquisition technique for measuring a wideband sparse signal (i.e., a multiband signal) is presented in this paper. The proposed architecture employs a combination of dual-rate time-interleaved undersampling hardware and associated multicoset back-end signal processing algorithms. In dual-rate sampling hardware, a pair of uniform samplers is used to acquire a common incoming wideband sparse signal while the operation frequencies of the two samplers have a small frequency offset. Due to the sampling frequency offset, the time grids of the samples obtained from the two samplers are irregularly spaced. These nonuniform periodic samples are then digitally re-sequenced and applied as input to a multicoset signal reconstruction algorithm. The multicoset signal reconstruction algorithm uses the re-sequenced nonuniform periodic samples to achieve a perfect reconstruction of the original wideband signal with an enhanced time resolution beyond the sampling hardware's capability. Compared to the conventional multi-channel sampling approach commonly used with multicoset algorithms, the proposed method uses fewer sampling channels and does not require their accurate clock phase adjustment.