On the data services of secondary user with primary exclusive region

In this paper, we propose a scheme to evaluate performance of data services of secondary users (SUs) in Cognitive Radio (CR) CDMA networks. Specifically, we develop a simulation test bed for analyzing throughput and delay performances of a SU in a single cell, where primary users (PUs) are present in an exclusive region of operation, viz., primary exclusive region. CR users or SUs which are present only outside the exclusive region belong to an infrastructure less ad hoc network that coexists with a primary radio network (PRN) forming pair wise ad hoc links. We assume spectrum underlay type of spectrum sharing, where SUs transmit in presence of PUs maintaining a predefined interference limit for primary radio network (PRN). A SU transmits packetized data for its corresponding receiver. A stop and wait ARQ protocol at MAC layer has been assumed for packet retransmission by SU. Effects of various network and channel parameters such as cell radius, standard deviation of shadow fading on the several performance metrics are indicated.