Packet timeout probability for uplink spectrum sharing

In this paper, we consider an uplink spectrum sharing cognitive radio network (CRN). In particular, we assume that μ secondary user (SU) transmitters (SU-Txs) communicate with an SU receiver (SU-Rx) in the presence of a single primary link. Under the joint constraint of the primary user (PU) outage probability and SU-Tx maximum transmit power, the SU transmit power policy is obtained. Moreover, the SU-Tx with a minimum transmission time is scheduled for transmission. Accordingly, the cumulative distribution function (CDF) of packet transmission time is derived under independent but not necessary identically distributed (i.n.i.d.) Rayleigh fading channels to evaluate the packet timeout probability. Numerical examples are provided to investigate the impact of the SU transmit power policy, the interference from the PU transmitter (PU-Tx) to the SU-Rx, the number of SU-Tx, and the packet size on the secondary network performance. The results indicate that the packet transmission time can be minimized as the number of SU-Tx becomes large.