Performance analysis of opportunistic scheduling with HARQ for cognitive radio networks

This paper analyzes the secondary network performance under the joint constraint of the primary user (PU) peak interference power and maximum transmit power limit of the secondary user (SU). In particular, N SU transmitters (SU-Txs) communicate with an SU receiver in the presence of a primary network with a PU transmitter and multiple PU receivers. Moreover, we exploit opportunistic scheduling where the SU-Tx with the best channel condition is scheduled for transmission. Analytical expressions of the outage probability and symbol error probability of the SU are obtained considering either perfect or statistical knowledge of the PU channel gains. Furthermore, we analyze the SU throughput for delay constrained applications with two hybrid automatic repeat request protocols, namely, repetition time diversity and incremental redundancy. Numerical results are provided to assess the effect of the number of SU-Txs and number of packet retransmissions on the secondary network performance. In addition, the impact of the primary network parameters on the secondary network is investigated.