Practical architecture of a broadband sensing receiver for use in cognitive radio

This paper proposes a dedicated sensing receiver architecture that addresses some challenges of broadband sensing in Cognitive Radios. Specifically, we address broadband sensing challenges for delay sensitive applications such as voice. A subjective calculation of an acceptable voice delay is used as a reference in our analysis. In the proposed architecture, fast response and accurate sensing is aided by the combination of power sensing at RF, baseband and in the digital domain. Since the sensing workload is distributed, the performance requirement on the main receiver is relaxed. The proposed architecture provides the ability to perform adaptive coarse and fine sensing at different points in the receiver chain. The estimated sensing time is derived and simulation results to illustrate the performance improvement are presented.