Asymptotic Performance Analysis of Generalized User Selection for Interference-Limited Multiuser Secondary Networks

Abstract

We analyze the asymptotic performance of a generalized multiuser diversity scheme for an interference-limited secondary multiuser network of underlay cognitive radio systems. Assuming a large number of secondary users and that the noise at each secondary user's receiver is negligible compared to the interference from the primary transmitter, the secondary transmitter transmits information to the k-th best secondary user, namely, the one with the k-th highest signal-to-interference ratio (SIR). We use extreme value theory to show that the k-th highest SIR converges uniformly in distribution to an inverse gamma random variable for a fixed k and large number of secondary users. We use this result to derive asymptotic expressions for the average throughput, effective throughput, average bit error rate and outage probability of the k-th best secondary user under continuous power adaptation at the secondary transmitter, which ensures satisfaction of the instantaneous interference constraint at the primary receiver caused by the secondary transmitter. Numerical simulations show that our derived asymptotic expressions are accurate for different values of system parameters.

Transmit Power Policy and Ergodic Multicast Rate Analysis of Cognitive Radio Networks in Generalized Fading

“…Therefore, the SU-Tx must transmit at a power that keeps the outage at each of the PU-Rx below a predetermined level. Thus, transmit power policy at the SU-Tx can be mathematically formulated as follows [18], [19],…”

“…Similarly, recent contributions [18], [19] have also considered the performance of an interferencelimited underlay CRN relying on continuous power adaptation at the SU. In [19], the secondary transmitter is assumed to transmit information to the specific SU, having the kth highest signalto-interference ratio (SIR).…”

“…In [16], different-power adaptive transmit antenna selection (TAS) schemes were analyzed for the underlay CRN. Furthermore, the authors of [17] have determined the optimal rate sharing parameters for both the SU and the PU, so that the achievable rates were maximized.Similarly, recent contributions [18], [19] have also considered the performance of an interferencelimited underlay CRN relying on continuous power adaptation at the SU. In [19], the secondary transmitter is assumed to transmit information to the specific SU, having the kth highest signalto-interference ratio (SIR).…”

“…Furthermore, the authors of [17] have determined the optimal rate sharing parameters for both the SU and the PU, so that the achievable rates were maximized.Similarly, recent contributions [18], [19] have also considered the performance of an interferencelimited underlay CRN relying on continuous power adaptation at the SU. In [19], the secondary transmitter is assumed to transmit information to the specific SU, having the kth highest signalto-interference ratio (SIR). The authors of [18] have also investigated the ergodic capacity of the secondary network in an underlay CRNs contaminated by the interference arriving from the primary network in conjunction with various scheduling schemes, including a multicast scheduling (MS) scheme designed for enhancing the fairness among the users.…”

“…Quite recently, the authors of [57] derived the statistical upper channel capacity bounds for FAS systems using EVT in the large-scale limit for Rayleigh fading channels. Furthermore, in [19] EVT is used for determining the average throughput of the k-th best SU under continuous power adaptation at the SU. Even though these are asymptotic results, they are observed to hold fairly well even for 20 receivers in the SU network.…”