Sensing-throughput tradeoff in a cognitive radio under outage constraints over non-identical fast fading Rayleigh channels

摘要

Sensing-throughput tradeoff under outage constraints has been studied before by assuming that sensing channels are independent and identically distributed (i.i.d). However, the plausible and reasonable assumption is that the sensing channels are independent but not necessarily identically distributed (i.n.i.d). In this work, we derive a closed form expression for the false alarm probability of cooperative spectrum sensing using an energy detector under outage constraints. This false alarm probability relies upon a new threshold which takes into account an outage constraint on the probability of detection due to the i.n.i.d slow and fast fading Rayleigh channels. The results showed that the throughput still improves as the number of secondary users increases over i.n.i.d Rayleigh fading channels. In addition, the throughput degrades dramatically as we move from fast fading to slow fading ones.