Sensing-throughput tradeoff for OFDM-based cognitive radio under outage constraints

Abstract

Sensing-throughput tradeoff under outage constraints has been studied before with an energy detector (ED). However, the ED does not work well in the presence of noise power uncertainty. So we study sensing-throughput tradeoff by using an autocorrelation detector (AD) for an OFDM signal. In this paper, we derive a closed form expression for the false alarm probability over both Nakagami-m and Rician fading channels. This false alarm probability relies upon a new threshold which takes into account an outage constraint on the probability of detection due to fading environments. The results show that the throughput improves with an increase in the Nakagami-m fading parameter and the Rician factor. In addition, the throughput improves dramatically with an initial increase of the number of multipath and then levels out.