On the performance of spectrum handoff for link maintenance in cognitive radio

Cognitive radio (CR) has the potential for resolving the spectrum scarcity issue in wireless communications. A CR device can establish unharmful links in the spectrum of the legacy system. Among many enabling functions for CR, spectrum handoff can restore CRpsilas connection when the primary user appears in the occupied channel. In this paper, we study three types of spectrum handoff for the link maintenance: (1) non-spectrum handoff method, (2) the pre-determined channel list spectrum handoff, and (3) the spectrum handoff based on radio sensing scheme. We examine the performances of the three mechanisms in terms of the link maintenance probability and the effective data rate of the secondary userpsilas transmission. Our numerical results show that erroneous channel selection probability, radio sensing time and the number of handoff trials are important for spectrum handoff schemes. We also provide the design guideline for these parameters.