  Cognitive radio (CR) requires spectrum sensing over a broad frequency band.
One of the crucial tasks in CR is to sample wideband signal at high sampling
rate. In this paper, we propose an acquisition receiver with co-prime sampling
technique for wideband sparse signals, which occupy a small part of band range.
In this proposed acquisition receiver, we use two low speed analog-to-digital
converters (ADCs) to capture a common sparse multiband signal, whose band
locations are unknown. The two ADCs are synchronously clocked at co-prime
sampling rates. The obtained samples are re-sequenced into a group of uniform
sequences with low rate. We derive the mathematical model for the receiver in
the frequency domain and present its signal reconstruction algorithm. Compared
to the existing sub-Nyquist sampling techniques, such as multi-coset sampling
and modulated wideband converter, the proposed approach has a simple system
architecture and can be implemented with only two samplers. Experimental
results are reported to demonstrate the feasibility and advantage of the
proposed model. For sparse multiband signal with unknown spectral support, the
proposed system requires a sampling rate much lower than Nyquist rate, while
produces satisfactory reconstruction.
