Cascaded Clear Channel Assessment: Enhanced Carrier Sensing for Cognitive Radios

In this paper, a new clear channel assessment (CCA) method: cascaded-CCA, is proposed that is apropos for next generation cognitive radios. The primary motivation for the proposed approach is to integrate the respective advantages of two ´standard´ CCA mechanisms (energy detection and preamble detection) to arrive at a new dual-threshold CCA family that can provide greater flexibility towards tuning MAC performance. The performance of cascaded-CCA is explored via MATLAB simulations that implement the CCA modules and medium access control (MAC) protocol for IEEE 802.11 and IEEE 802.15.4 as representative examples.