Channel-Aware Random Access in the Presence of Channel Estimation Errors

In this paper, we consider the random access of nodes adapting their transmissions based on the local channel state information (CSI) in a decentralized manner, which we call channel-aware random access (CARA). The CSI at each node is not perfect but has some errors. Thus, the performance of CARA depends on the accuracy of CSI, which is the focus of this paper. Specifically, an exact stability analysis is carried out for the scenario in which two sources that have bursty packet arrivals compete to access a common receiver. The analysis needs to resolve the complex coupling between the queues at the sources having interdependent services. The analysis also takes into account the compound effects of the multipacket reception capability at the receiver. In summary, our contributions in this paper are twofold: first, we obtain an exact stability region of CARA in the presence of channel estimation errors; such an assessment is necessary as errors in channel estimation are inevitable in practical situations. Second, we compare the performance of CARA to that achieved by the class of stationary scheduling policies making decisions in a centralized manner based on the CSI feedback.